Home

1990 , Volume , Issue Oct-1990

1. 78 Statistical Simulation Chee K Chow Manufacturing develop mentengineer Chee Chow specializes in computer integrated manufacturing manufacturing data bases and analog and microwave circuits He joined HP s Santa Clara Technology Center in 1984 and has want done research in statistical circuit simulations for circuit designs He recently transferred to HP s Microwave Semiconductor Division Inthe past Chee worked on bipolar high speed circuits at HP and researched coal conver sions and materials at Washington State University where he received his PhD degree in 1974 in phys ical chemistry He aiso earned an MS degree in 1984 in electrical engineering from Oregon State University Cheeis the author of 15 technical art cles on fue processing physical chemistry and electronics 82 Air Flow Analysis Kent P Misegades lt As manager of compuler fluid dynamics applications at Cray Research Inc Kent Misegades collabo rated with HP on airflow simulation in the HP 9000 Model 850 computer At Cray Research he Is sponsible for all fluid dynamics related applica tions in the aerospace automotive metals elec tronics and chemical industries His experience also includes work as an aerodynamicist for Dor nier GmbH in West Germany from 1980 to 1984 member of the AIAA Kent s professional in terests include aircraft design and fluid mechanics He is a graduate of Auburn
2. f 2 8 MHz Oe H Ha 1 resonance where H is the applied dc magnetic field and H is the internal anisotropy field 70 Oe for YIG Using this equa tion the maximum usable frequency of a YIG sphere can calculated to be about 64 GHz assuming that the material used in the tuning magnet pole tip has the highest satura tion flux density available approximately 23 kilogauss for a cobalt iron alloy The anisotropy field H can be thought of as a built in magnetic field that acts along a crystal axis or in some cases a crystal plane When the anisotropy field is parallel to the applied field it gives a frequency offset that reduces the applied dc magnetic field needed for reso nance at a given frequency It was obvious that a new resonator material would be H 25 5 kOe H 0 01 kOe go Sot H 12 5 kOe 50 0 0 GME 10 kOe 5 40 735 H 8 kOe 2 30 lt or L T t 5 10 15 20 25 Applied DC Magnetic Field H kOe Fig 1 Ferrite resonance frequency as a function of dc mag netic field for various values of the anisotropy field required to make tunable bandpass filters to serve as pre selectors for the HP 11970 Series harmonic mixers covering from A band 26 5 to 40 GHz up to V band 50 to 75 GHz Using equation 1 it can be seen that if ferrite materials similar to YIG but with higher H could be found then it would be possible to build m
3. Fig 3 Data organization for text objects created with the function ZtCreate or ZtClone intreturn val Ztldtexti Id text2 Id pointld object identifiers arglistfortextobject containing attribute valuepairs The text Arglist and the point Arglist are the same asin the previous example arglistforcloned text object static ZtArgListltemcloneArglist ZIPOINT ZtValueType NULL ZtSTRING ZtValueType NULL NULL ZtVatueType NULL The reference points and the first text object are created the same as inthe previous example createthesecondtextobjectat 10 60 usingthe ZtClone function y 60 0 return val ZtChange pointld pointArglist NULL cloneArglist 0 ZtValue ZtValue Type pointld cloneArglist 1 ZtValue ZtValueType Second text object text2 Id ZtClone Text Id cloneArglist NULL free point objectif itisno longer needed 7 ZtFree pointld NULL ZiClone is particularly useful for models and composite objects With one call the model or the composite object and its descendants can be duplicated A call to ZtClone can be modified to control the depth of cloning for a list of objects In the following example there are two model ob Copr 1949 1998 Hewlett Packard Co jects that have identical properties except for the back ground and foreground colors The first model object has been created with the child list modeltid Instead of repeating the
4. the back cover that is closest to you When submitting a change of address piease include your zip or postal code and a copy of your old label Submissions Although articles in the Hewlett Packard Journal are primarily authored by HP employees articles from non HP authors dealing with HP related research or solutions to technical problems made possible by using HP equipment are also considered for publication Please contact the Editor before submitting such articles Also the Hewlett Packard Journal encourages technical discussions o the topics presented in recent articles and may publish letters expected to be of interest to readers Letters should be brief and are subject to editing by HP Copyright 1990 Hewlett Packard Company All rights reserved Permission to copy without fee all or part of this publication is hereby granted provided that 1 the copies are not made used displayed or distributed for commercial advantage 2 the Hewlett Packard Company copyright notice and the title of the publication and date appear on the copies and 3 a notice stating that the copying is by permission of the Hewlett Packard Company appears on the copies Otherwise no portion of this publication may be produced or transmitted in any form or by any means electronic or mechanical including photocopying recording or by any information storage retrieval system without written permission of the Hewlett Packard Company Please address inquiries submissi
5. State Table File Jusers test Device xx Endofcase ECASE IDLE WAIT send message f CASE2 Good Y F State Command f IDLE WLRA 020002012000 000000 000 0015020003000 f Endolcase ECASE IDLE IDLE reply message CASE 3 State Command IDLE WURA 012000 WAIT WLRA 1020006 End of case ECASE WAIT WAIT ACK CASE 4 7 State Command IDLE WURA 1012000 WAIT WLRA 020025 End of case i ECASE WAIT WAIT NAK Fig 10 Action command file OCTOBER 1990 HEWLETT PACKARD JOURNAL 69 Copr 1949 1998 Hewlett Packard Co HP UX Message Queues Factory Floor Device Intertace HP UX Message Queues Fig 11 Testing interfaces vices perform checksums and pass them to the next level This ensures that all messages are acknowledged promptly by a dedicated protocol interface while less time critical functions are handled by separate protocol interfaces Fig 15c shows three protocol interfaces each dedicated to a port Device specific message processing is done for each port The upper level PI4 directs and organizes mes sages before passing them up to the application A developer can choose where to put common functions The performance will be slightly better when the number of protocol interfaces in serial is smaller since fewer mes sages are passed between processes On the other hand a centralized function may be desirab
6. OCTOBER 1990 HEWLETT PACKARD JOURNAL 61 Copr 1949 1998 Hewlett Packard Co HP DIS A Development Tool for Factory Floor Device Interfaces The HP Device Interface System provides a development facility that includes a high level Protocol Specification Language a testing facility and a run time facility for device interfaces that run in an HP UX environment on HP 9000 computers by Kent L Garliepp Irene Skupniewicz John U Frolich and Kathleen A Fulton tween computers and factory floor devices can be a serious challenge in factory automation projects These factory floor devices consist of programmable logic controllers PLCs robots numerically controlled ma chines gauges scales and other devices The problem is that they may come from many manufacturers and may have different proprietary interfaces For a few major brands of programmable controllers there are off the shelf communications packages that can be purchased This solution has limited applicability if the needs vary from what is implemented in the package If flexibility is needed a customized interface can be written At present development of specific device inter faces is a time consuming exacting and expensive process requiring a fairly high level of expertise The process gen erally consists of characterizing the device s communica tion protocol and then writing changing or enhancing programs subroutines and test suites This pro
7. state receives before any other message is sent to the state except exit Hit A state gets a hit message when the user presses a mouse button in the workspace window that is currently active HP IVIBuild allows the user to construct and edit as many windows as desired but only one can be active at a time To activate another window the user only has to press a mouse button over the window that is to become active Depending on their hit methods states are classified as either multiaction or single action states A multiaction state requires the user to select multiple points in the active window to perform the operation im Interstate Transition Es return Current State a Intrastate Transition input __ backup User S undo _ Workspace start return Current_State b Fig 7 HP IVIBuild state protocol a An interstate transition b Intrastate transition 36 HEWLETT PACKARD JOURNAL OCTOBER 1990 plemented by the state An example of a multiaction state is one that allows the user to create polylines or splines When the user presses a mouse button in the active window and a multiaction state is the current state the action of the state is said to go forward Fig 8 shows the intrastate transition diagram for a multiaction state that translates objects A single action state does not require a hit in the active window to go forward Single action states can only do one
8. driver currents flowing in the inductance of the package and circuit board conductors To produce mean ingful simulations it is necessary to include models of all these components in the circuits The simulations are par ticularly sensitive to the IC package model since the pack age lead inductance accounts for most of the inductance L in the Ldi dt term for computing power supply bounce The values of the power supply inductances that need to be added in the simulations range from about 70 picohen ries to about 0 5 nanohenry In addition ground models Bounce in ground and power supplies relers to a temporary droop or rise in the supply voltage caused by large currents drawn by devices using the supplies GND Plane Plating Bars Signals GND Plane Signals GND Plane Vos Plane Dielectric Layer 7 TL 7 Plane Dielectric Layer 8 Dielectric Layer 9 GND Plane Von Plane Dielectric Layer 10 TL 10 Dielectric Layer 11 TL 11 Vo Plane Fig 1 PGA pin grid array con GND Plane struction detail not to scale All dielectric layers are 0 008 inch thick OCTOBER 1990 HEWLETT PACKARD JOURNAL 73 Copr 1949 1998 Hewlett Packard Co and signal trace models including cross coupling need to be included in the system simulations Model Verification Creation of electrical models for the PGA was facilitated by various software tools and by leveraging previous w
9. 1 0 5 110 10 0 005 NDCs WC and for the y coordinate SF 1 0 5 85 10 0 0067 NDCs WC To transform the pushbutton coordinates shown in Fig 10a from WCs to NDCs 0 05 NDCs 0 3 NDCs Pix 2 P 10 SF 0 067 NDCs Pa 47 5 SFy 0 318 NDCs Fig 10b shows the pushbutton scaled to NDC coordinates The NDC system maps the coordinate 0 0 0 0 to the lower left corner of a window Therefore if the viewable WC region does not map the coordinate 0 0 0 0 to the lower left corner of the window a translation factor is added to the NDC coordinates The translation factors are computed as SF x WC origin T SF x WG origin wow ABC Original Widget Widget Scaled Anc Larger Widget Scaled Xr Smaller Fig 11 The effects of scaling widgets larger and smaller around characters For the pushbutton example the translation factors are T 0 005 x 10 0 05 NDCs T 0 0067 x 10 0 067 NDCs y Adding the translation factor to the NDC points P and P results in 0 05 0 05 0 NDCs 0 3 0 05 0 25 NDCs 0 067 0 067 0 NDCs 0 318 0 067 0 25 NDCs Fig 10c shows the results of the translation Like most graphics packages the API follows the conven tion of defining the origin in the lower left corner of the drawing area However because the X Window System defines the origin to be the upper left corner an ad
10. An application can have any number of windows They can overlap one another and they can be manipulated using a window manager or Model 12 High Level High Level Model 21 High Level Primitive Row Column Composite Text Primitive Rectangle Primitive Row Column Composite Toggle Button Primitive Pushbutton Primitive Text Primitive Fig 1 The API object hierarchy of a simple application OCTOBER 1990 HEWLETT PACKARD JOURNAL 11 Copr 1949 1998 Hewlett Packard Co the API functions The last high level object the model object is the only valid child of a window object The model object allows an application to put composite primitive or other model objects into a single group or collection When these objects are grouped together func tions can be performed on them as if they were a single object At the same time each part will retain its individu ality Models can represent a symbol or template that can be saved and restored as many times as desired Models can have other models composites or primitive objects as children Primitive Objects These are basic visual objects that are part of one of two categories graphic primitives or widget primitives The graphic primitives are visual objects e g circles rectangles and arcs that can receive mouse input An application can use these objects for graphically repre
11. data In the case of a read request the data field from the computer contains the address and the length of the re quest The reply data from the device consists of the values requested In the case of a write request the data field from the computer contains the address and the values for the request The reply data from the device consists of an inter nal status for the request In the event of a communication failure either the com puter or the device can reply with a failure message NAK The protocol interface must also recognize that no response TO is a failure Other failure mechanisms are not taken into account in this example PLDEFINITIONS Runtime Name Runtime File Name Runtime Type P Runme Prony 51 Port Name AB PORT DEFINITION 02 03 0405 Queue Link 05 gt Device xx Device Q3 Q4 Device xx Device lt Q2 Fig 6 Device interface configuration file Copr 1949 1998 Hewlett Packard Co In Finite State Machine The finite state machine model has been used in such diverse disciplines as computer design neurophysiology linguistics au tomata theory and communications The finite state machine model is a natural way to describe systems that process signals This model is particularly convenient for specifying how mes sages are processed in device protocols Two standard representations used to describe a particular finite state machine are the state table and
12. development and testing of HP DIS software for HP 9000 computers as amember of HP s Industrial Applications Center in Sun nyvale California After joining HP in 1959 he pro Kathleen A Fulton After joining HP s Engineer 984 software engineer WE Kathy Fulton helped de 1 velop the equipment con trol portion of HP s Semiconductor Productiv ity Network She also de signed and coded the con figuration initialization and run time portions of the HP DIS product and is now testing and maintaining HP Sockets software at HP s Industrial Applications Center Before joining Kathy was a semiconductor fabrication en gineer at Burroughs Corp anda software develop ment engineer Trilogy Corp and Amdahl Corp member of the IEEE she received her BA degree in 1975 in applied physics and information science with a specialization in computer science from the University of California at San Diego Born in Reno Nevada Kathy is married and lives in Cupertino California Her interests include traveling to unusual locations reading science fiction and quilting Irene Skupniewicz For the past lour years at HP Irene Skupniewicz has worked as an RAD software engineer in the develop ment of manutacturing ap plications Currently she is inthe Manufacturing Appli cations Group working on the Device Interface Sys tem and Software Integra tion Sockets two products that are of HP s in dustria
13. intemal TimePeriod gt TimeOutVal retry exceeded internal RetryCount gt MaxRetry intemal BocFiag TRUE intemal BocFlag FALSE States IDLE HOME Homestate State table IDLE send message DclO Read Applic read RegPacket Result START Build outgoing buffer DcMove ReqPacket dst DataPacket dst DcMove HP id DataPacket src DcMove ReqPacket cmd DataPacket cmd DcMove StatusOK DataPacket sts DcMove tns DataPacket ns DcMove ReqPacket data DataPacket data DcCksum Caiculate DataPacket data AB DataPacket boc END Build outgoing buffer DclO Write Device Write DataPacket Result DcMove 0 RetryCount DcCntr Increment tns DcClock Start timer TimePeriod TimeOutVal WAIT IDLE reply message DclO Read Device read O Text Result DcIO Write Device Write ReplyAck Result IDLE WAIT ACK DcCiock Stop timer TimePeriod DclO Read Device read Text Resuit DcCiock Start timer TimePeriod TimeOulVal WAIT WAIT NAK DcCiock Stop timer TimePeriod DclO Reac Device read Text Result DclO Write Device Write Q DataPacket Result DeCnitr Increment RetryCount By one DcCiock Start timer TimePeriod TimeOutVal WAIT WAIT reply message DcCiock Stop timer TimePeriod DclO Read Device read DataPacket Result DcCksum Check Data
14. targets of messages being sent to it The box on page 29 provides a brief review of object oriented concepts and the HP IVI object oriented environ ment Input Handling Messages sent by the state machine to a particular state can result in either an interstate transition or an intrastate transition depending on the message that is sent Interstate transitions are transitions among the various state objects of HP IVIBuild and intrastate transitions are transitions within a particular state object A new state becomes current by an interstate transition Interstate transitions are handled by the state machine All input in HP IVIBuild goes through the state machine The state machine is an API callback function that is attached to all the components of HP IVIBuild s user interface and all of the workspace windows created by the user The objects in the HP IVIBuild user interface are called user interface objects and the objects created by the user during an HP IVIBuild session are called user workspace objects Using this mechanism HP IVIBuild is able to control the context of the user s input This is an important require ment of any interactive design tool The state machine performs the following functions It changes the active workspace windows when the user requests it It interprets the meanings context of the mouse buttons when they are pressed in the active workspace window according to a user definable mouse button ma
15. the experiments the boards had actual components on them Conclusions Steady viscous three dimensional air flow within a computer SPU has been analyzed using finite element model ing General flow characteristics including velocity profiles and pressure drop across the system were computed Nu merically simulated particle traces were recorded using video equipment It was found that numerical simulation of particle traces can show good qualitative features of the flow through the system The particle traces show some extremely interesting flow characteristics that could not have been known easily otherwise The computed velocity profiles through the boards and the computed system pres sure drop have reasonably good accuracy Modeling pre dicted the air velocities through the CPU board slots to be about 1 5 m s to 2 75 m s whereas the experimental mea surements showed about 1 25 m s to 2 25 m s However finite element modeling can be relatively expensive in terms of computation time References 1 H Schlichting Boundary Layer Theory McGraw Hill 1979 2 FIDAP Theoretical Manual Fluid Dynamics International OCTOBER 1990 HEWLETT PACKARD JOURNAL 87 Copr 1949 1998 Hewlett Packard Co Faz DICK DOLAN 152U3 33955113 LEWES KAREN E GRIDRATE HEADQJA1TE1S 5 Div 000 2033 Hewlett Packard Company 3200 Hillview Bulk Rate Avenue Palo Alto California 94304 U S Postage Paid ADDRESS CORRECTION REQUESTED Hewl
16. the top frequency in the band The one wavelength cavity mode can thus be eliminated by shortening the transverse guide However this brings the one half wavelength cavity mode in band at about 15 of the band The one half wavelength cavity mode is not as strong as the one wavelength mode and can be suppressed very well Fig 12 by introduction of a distributed loss in the transverse guide to detune the cavity This loss is effected by a thin sheet of Kapton plastic between the sides of the transverse guide and the iris plate to allow some energy to leak out The Kapton sheet is shown in Fig 13 which also shows the four sphere filter assembly Four sphere filters using scandium doped barium fer rites as resonators are presently being built in A Q U and Fig 10 Four sphere filter design OCTOBER 1990 HEWLETT PACKARD JOURNAL 53 Copr 1949 1998 Hewlett Packard Co Ref 0 0 dB 10 0 dB au Frequency GHz ds Fig 11 First four sphere filer response shows cavity mode resonance V bands They typically have insertion loss of 8 to 12 dB 3 dB bandwidth of 120 to 200 MHz image rejection greater than 55 dB and off resonance isolation greater than 70 dB These performance figures represent trade offs that were made between the different parameters For instance by mounting the spheres closer together top to bottom a four sphere V band filter was made having 4 to 6 dB insertion loss across the band Unfo
17. the voltage drops across all of the above items The capaci tor across the coil shunts unwanted high frequency cur rents away from the coil The Zener diode across the coil provides a discharge path for the coil at the end of a sweep when the current through the transistor goes to zero The effect of temperature on the filter s frequency is another consideration in filter tuning Some filters such as the Q band filter have very little frequency drift with temperature while others such as the V band filter are very sensitive to temperature With a constant coil current a V band filter drifts at a rate of 11 4 MHz C For a tem perature increase of 50 the center frequency of the filter would increase by nearly 600 MHz Compensation for the temperature drift had to be considered because the 3 dB bandwidth of the filter is typically between 120 and 200 MHz and this would mean that an input signal would no longer be within the passband of the filter Temperature and Delay Compensation Temperature drift is compensated by monitoring the tem perature at the filter and modifying the coil current A thermistor network is used to monitor the temperature of the filter The thermistor network consists of a thermistor composite composed of two thermistors encapsulated in epoxy and two linearizing resistors The thermistor com Differential Amplifier High Frequency cs Pas Reference Voltage ial Amplifier Low Frequency E
18. to achieve the required performance The design and performance of the HP 11974 Series preselected mixers are described in the article on page 49 The article on page 59 gives the reasons for the choice of scandium doped M phase barium ferrite for this application and tells how the spheres are made Software for computer integrated manufacturing CIM is in great demand and HP development laboratories are responding with a steady stream of new products Two are featured in this issue The first HP Interactive Visual Interface or HP IVI uses object oriented design the industry stan dard X Window System and widget technology to help application software developers provide graphical user interfaces for industrial applications Widgets are standard pieces of software that produce pushbuttons scrollbars and the like on computer screens HP improves its users productivity in designing user interfaces because it is interactive facilitates saving and reusing interfaces and doesn t demand that users know the details of the X Window System or widgets The article on page 6 gives an overview of HP IVI which consists of two main parts Users construct their interfaces using HP IVI s interactive editor described on page 32 and then activate the objects created with the editor by writing C language programs using a toolkit of functions provided by HP IVI s application program interface Details of the application program interface s object orie
19. 1 57 1 33 1 53 1400 1200 1000 800 400 200 od 100 80 40 20 60 Output Offset mV Fig 6 Distribution of the output offset of the op amp from production data The mean is 49 mV and the standard de viation is 11 mV Copr 1949 1998 Hewlett Packard Co production data the low frequency output offset voltage of the op amp had been observed to be large The op amp output offset voltage is defined as the output voltage of the op amp when the two high frequency outputs inverting and noninverting are equal Under balanced conditions the output offset should be close to zero It was not known what the standard deviation caused bv process latitudes should be Fig 6 shows a typical distribution of this param eter from six months of production data It has a mean of 49 mV and a standard deviation of 11 mV The op amp circuitry has 22 random variables of which 12 are highly matched resistors and 10 are the transistor model parameters Correlated simulations were carried out as for the first example A 200 sample simulation revealed the distribution of the offset voltage to have a mean of 11 mV and a standard deviation of 3 4 mV Such a large dis crepancy between the manufactured and simulated distri butions suggests some hidden process anomaly that has not been discovered Subsequently the process defect that caused this wide distribution of the output was identified The circuit was redesig
20. 1998 Hewlett Packard Co fluid flow characteristics On all solid surfaces of both physical and blocked re gions a no slip velocity boundary condition was specified At the two air flow entrances on the top front and back of the cabinet no boundary conditions were set For the air outlet at the bottom of the cabinet a constant velocity bound ary condition was defined However for the outlet bound ary condition not enough information was available ini tially The flow rate produced by a fan is dependent on the pressure drop it experiences Flow rates are given in tabular or graphical form as a function of pressure drop The data used in this work was for the fans running at 60 Hz at sea level Since we did not know the pressure drop of the system at the outset it was not possible to know the fan flow rate that would define the air exit boundary con dition To get around this problem the following iterative procedure was used 1 An initial fan flow rate was guessed 2 For this given fan flow rate the flow field including the pressure drop was calculated based on the uniform exit velocity across the exit area that would result in the same volumetric flow rate as produced by six fans 3 For this computed pressure drop the corresponding flow rate from the fan manufacturer s performance curve was found 4 An average of this new flow rate and the previously guessed flow rate was used to calculate the exit velocities which were u
21. 5 768 1 1 383 Modeling Coordinates The API provides modeling transformations that allow any object within the user interface hierarchy to be trans formed by scaling enlarging or shrinking rotation and translation This lets the user draw a symbol that can be reused by providing only the data that differentiates its position and size from another instance of the symbol The API concatenates modeling transformations so that an ob ject is affected by the transformations on its ancestors This allows an entire subhierarchy of objects to be transformed by one operation on a common ancestor instead of requiring transformations on every object in the subhierarchy These transformations are used when an object is being drawn The modeling transformation values are converted to WCs by multiplying the transformation on an object to its WC attributes A current transformation matrix CTM is main tained during a drawing pass on the objects Each object multiplies its transformation matrix with the CTM contain ing the transformations of its ancestors In the API the CTM is initialized to be the VTM Doing this reduces the number of matrix multiplications and improves the perfor mance of the drawing operation Adjustments and Scaling Besides allowing the application developer to work in a display resolution independent manner when creating the windows for an application the world coordinate system allows a user to resize the wi
22. A TDR does not have the ability to drive such a low impedance load Since simulations are done with the HP Spice software package using models made up of discrete R L and C elements these are the parameters that need to be verified Because TDR or direct measurements with an impedance analyzer cannot give this kind of detail it was deemed necessary to develop another measurement technique which is described in the following sections Capacitance Measurement A typical PGA signal trace structure including the signal wirebond and the PGA pin is modeled in the passive cir cuit of Fig 2 This is a useful model for HP Spice simula tions It can also be approximated in the form of transmis sion lines with Z VL C and propagation time t VL C The transmission line approach is more dif ficult to apply when the mutual coupling and resistive losses are important This is the case in any IC package where a number of I O lines and internal circuits are switching simultaneously The RLC equivalent is applica ble to any circuit where the time delay of the element is less than about half the shortest rise time of the propagating signal In the case of pin grid array packages the odd geometry gives the device non TEM properties for exam ple the capacitive and inductive coupling coefficients are not equal To overcome the shortcomings of traditional measure ment techniques the following method is used The R L and C values in
23. Call Windows Calibacks Fig 5 The API server object event handling loop OCTOBER 1990 HEWLETT PACKARD JOURNAL 23 Copr 1949 1998 Hewlett Packard Co Callbacks on Graphics Graphic objects include shapes such as arcs rectangles and circles Because graphic objects can be manipulated the same as windows and widgets in the HP IVI environ ment we decided to have button press and button release events associated with them Therefore graphic objects need callback functions For example an octagon shaped graphic object representing a stop sign may require a callback object with a method for stopping some operation Callbacks on graphic objects are handled differently from widgets Since the graphic objects are not widgets the Xt Intrinsics cannot be relied on to call API functions when an event occurs on a graphic object All widget and graphic objects have a corresponding extent object The extent ob ject consists of two point objects that define a rectangular region When associated with an object the extent defines the smallest rectangle that encloses an object see Fig 7 When the minifunction for window events detects a button press or button release it converts the x y coordinate posi tion of the sprite to a point object Since the window minifunction is called this indicates that the button event did not occur over a widget remember the widget mini function converts widget data to API usable data The button even
24. Fig 2 are measured using slightly different electrical circuits The only source used is a ramp generator and the only detector used is an oscilloscope with a matched 500 input impedance Fig 3 illustrates the mea surement of a capacitance such as the coupling capacitance between the two traces The use of a ramped input signal cancels effects of circuit elements that are not under test and aids in the interpretation of results The charging cur rent i t defines the voltage across the oscilloscope s chan nel 2 inputs and the unknown capacitance C can be calcu lated from C Vinax Rscope2dVin At a where voltage is measured at the center time of the Vgen ramp The voltage Vow is small but its accurate measurement is important to the determination of the parameter values The measurements that must be taken on the oscilloscope screen are the slope of the Vi ramp dV dt and the plateau voltage on V Matched coaxial cables be tween the instruments and the device under test introduce time delays but do not introduce any additional factors in the equation for C above For example losses in the coaxial cables from the sample to the oscilloscope will introduce no error if they are the same length for both channels since the measurement depends on the quotient of the measured voltages The voltage drops across the series resistance and inductance in the trace are small since they are in series with the capacitive impeda
25. LIST attribute Replacement An object can replace another object using ZtReplaceListindex to place the object at a specified index ZiReplaceListObject to place the object before an object with a known identifier ZtReplaceListTail to place the object at the end of a list replace a point object at the index position of a point list pointListid with a new point object newpointID pointListld Ztld of a ZtLIST OBJ to replace the 4 r object in newpointld the Ztld of the object to replace the indexed object with l replacedid the Ztid of the replaced object This variable may be given as NULL if this return value is not of interest Fig 7 Inserting the object pointld in the list pointListld at index 2 b Inserting the object insert pointld into the list pointListid in front of the object retpointid 1949 1998 Hewlett Packard Co Zild pointListid replacedid newpointid INT32 objlndex 2 int ret ZtReplaceListindex pointListid objindex newpointld amp replacedid The next code fragment illustrates using ZtReplaceListObject The object identifiers have the following meanings pointListld same as above point _index_1d the Ztld of the object to replace newpointid the 210 of the object to replace point index ld replacedid same as above ret ZtReplaceListObject pointListld point index Id newpointl
26. Library Definition File e g graphic Run Time Class Information File e g circle rtc Glue File e g classiibs c 1 Run on Library Definition File circle rte graphic h graphic c 2 Compile the Class Definition File Tircie c 3 Compile C Source File graphic c Generated from rtc Tool Z 49 c graphice 4 Glue Library Definition Object File T D graphic h Fig 13 The process of adding a new object to the API object hierarchy Copr 1949 1998 Hewlett Packard Co Object Oriented Design in HP IVI HP IVI is an object oriented system It uses a set of facilities called the HP IVI object oriented environment OOE to provide the framework for its implementation The OOE has two parts a messaging interface and a tool for compiling an external descrip tion of the class hierarchy into C language code The C code defines the dispatch tables used by the OOE s interface functions to perform messaging object communication Presented here are some basic concepts of object oriented design and an over view of how the OOE implements some of these concepts Object oriented design and programming are proving to be a natural and productive paradigm for software development be cause they enable developers to represent relationships among system components and the tasks to be performed on these components in a
27. O sphere alignment 167 505 3800 25800 950 63 M phase BaFe Sc O 3800 8000 430 39 wm s 670 81 17 3 890 9 300 500 U phase Ba Zn Fe sO o 3 900 4 800 310 Notes 1 Sc and dopings can be varied continuously 2 Y phase has planar anisotropy f 2 8 MHz Oe H H H when the anisotropy plane is aligned with both dc and RF fields Fig 3 Summary of hexagonal ferrite and YIG parameters a ferrite sphere with the applied magnetic field aligned with H will not all line up or saturate until a field of at least 47M 3 has been applied Third for very high Q unloaded Q ferrites at low frequencies such as YIG with fields between one and two times 47M 3 the effect known as coincidence limiting limits the amount of power that a ferrite device can handle to much less than 0 dBm There fore YIG spheres are generally used with applied fields above two times 47M 3 For hexagonal ferrite sphere tuned devices this power limiting effect has not been seen at power levels up to 20 dBm for our bandpass filter con figurations and thus should not present a problem for this application As Fig 5 shows scandium and aluminum dopings can be varied arbitrarily in M phase hexagonal ferrites to give the desired H The scandium doped M phase barium fer rite will satisfy the frequency range requirements at the lower
28. Systems Division in 1981 He has worked as a development engineer and a technical leadin the development of the HP Advanced Graphics Package the HP Device Independent Graphics Library the HP Manufacturing Automation Protocol pilot for General Motors Corp and the HP Graphics Inter face System Roger earned a BA degree in micro biology in 1976 an MS degree in microbiology in 1978 and an MS degree in computer science in 1981 all at the University of Hawai Born in Honolulu helives in San Jose California wh enjoys volleyball and baliroom dancing he Software engineer Mark Thompsorr joined HP s Data Systems Divis 1980 where he worked on disk diagnostics and util ities VO drivers for HP 1000 computers and a quality decision manage ment program For the HP IVI project he was respon sible for graphic objects the error handler and the quality function deployment analysis His profes sional interests center around 2D and 3D graphics Mark received his BS degree in computer en gineering from Boston University in 1980 Bo San Francisco California he lives in Berkeley His interests include automobile restoration beer mak ing photography bicycling gardening hiking mping and audio electronics jon in HP IVI Toolkit Mydung Thi Tran Software engineer Myung Tran was responsible for widget development test ing and native language support for the HP IVI pro ect She joined H
29. U S Air Force from 1963 to 1967 attaining the rank of sergeant Born in Bar ron Wisconsin he is married has two boys anda girl and resides in Fort Collins Colorado His hob include weight lifting and taking karate lessons with his children Dave says they hold advanced belts inthe martial arts but he s still working on the basics Frank J Perezalonso Frank Perezalonso specializes in hardware de sign engineering and analog circuit design and measurements He joined HP Laboratories in 1984 as a semiconductor process technician and is now a member of the technical staff of HP s Circuit Tech nology Group He worked on the electrical charac terization of the high performance HP 408C PGA integrated circuit package In the past Frank was involved in E beam lithography process develop ment evaluation and test of HP s membrane probe Gard and test methods for the electrical characten zation of IC packages Before he joined HP he worked on semiconductor processing for Fairchild Semiconductor Corp and as an instructor in math physics and semiconductor processing at Foothill College in Los Altos California He studied semiconductor processing at Foothill College re ceived a BSEE degree in 1985 from the University of Santa Clara and expects to receive his MSEE degree in December Born in Managua Nicaragua Frankis married has a daughter and lives in San Jose California He enjoys sports and teaching
30. ZIDo ZIERASE ZiDo ZIFLASH ZiDo ZILOWER ZiDo ZIRAISE ZiDo ZIREDRAW ZiDo ZIUPDATE Manipulate Lists ZtCheckListObject ZtCountList ZiGetListindex ZtGetListObject ZtGetListTail ZtinsertListindex ZtInsertListObject ZtinsertListTail ZiMergeListindex ZtMergeListTail ZiMergeListObject ZtRemoveListIndex ZiRemoveListObject ZtRemoveListTail ZtReplaceListindex ZtReplaceListObject ZtReplaceListTail Manipulate Argiists ZiFreeArgList OCTOBER 1990 HEWLETT PACKARD JOURNAL 13 Copr 1949 1998 Hewlett Packard Co Create and Free Objects Objects are created using the function ZtCreate Any attri butes that are required to be different from the defaults can be passed in the object ArgList when calling ZtCreate For all the attributes not included in the object ArgList the API will automatically set them to defaults Once an object exists multiple copies of this object can be made by cloning it with the function ZtClone ZtClone also allows the users to alter some of the attributes of the newly cloned objects in the same call The following example shows the creation of two text objects with one fixed size different text strings and differ ent positions on the display Fig 3 shows the data organi zation resulting from this example intreturn val Ztldtexti Id text2 Id pointld objectidentifiers arglist for text object containing attribute valuepairs static REAL
31. and going through the printed circuit boards and exiting the fan outlet region An interesting aspect of the results is that a substantial portion of the flow entering the I O side or the rear of the cabinet actually passes over the backplane obstruction in the top section and flows to the CPU side at the front of the cabinet It can also be seen that the velocities are low at the entrance increase between board slots and then decrease again at the exit of the board slots The air velocities are higher in the four CPU board slots than in the memory and I O board slots and are in the range of about 1 to 2 75 m s As mentioned earlier simulated particle paths or traces were recorded on video The traces represent the path that a massless particle would take through the computer cab inet if released at various locations along the inlet planes Such traces are very useful in giving a qualitative represen tation of the three dimensional complex flow field Using MPGS the Multi Purpose Graphics System from Cray Re search these traces were animated to show the details of the flow The animation very clearly shows the cross flow of air from the I O side of the cabinet to the CPU side and other complex features of the flow A typical picture of particle simulation is shown in Fig 6 Experimental Results Experimental measurements of the air velocities were carried out on an actual system with the help of a hot wire anemometer The cabinet wall
32. are designed to operate with three families of Hewlett Packard spectrum analyzers the HP 70000 modular spectrum analyzer family with the HP 70907B external mixer interface module the rugged portable spectrum analyzer family including the HP 8560A 8561B HP 8562A and HP 8563A and the HP 8566B a high performance R amp D bench spectrum analyzer Fig 17 shows the HP 11974 Series and the spec trum anal s Older models of these spectrum analyzer families can be made compatible by installinga retrofit kit To be compatible with the HP 11974 the spectrum analyzer must meet certain requirements First the spec trum analyzer must have a first LO frequency range of 3 to 6 GHz at the proper power level The nominal power level of the first LO output is 14 5 dBm to 16 dBm Second the first IF of the spectrum analyzer must be com patible with the HP 11974 Each spectrum analyzer men tioned above has a first IF of either 310 7 MHz or 321 4 MHz Finally the spectrum analyzer must provide a voltage output that is proportional to the frequency of the first LO 56 HEWLETT KARD JOURNAL OCTO s 2 882 8 8 8 z 600 50 60 70 80 Filter Frequency GHz ig 16 V band filter tracking error with temperature compen sation of the spectrum analyzer Each of the three spectrum analyzer families has a different definition for the tuning voltage provided Because
33. are sent to the application This is done through callback techniques based on the Xt callback mechanism There are also mechanisms and data structures to provide a linkage between X event data formats and API data formats Graphics Most graphics packages such as Hewlett Packard s Star base graphics package provide coordinate systems that allow users to write device independent graphics programs Since creating a user interface with the X Window System is currently done using pixels the API project team decided to provide API functions that enable user interface design ers the same type of device independent coordinate system features as offered by Starbase Graphics packages provide coordinate systems that Communicate with a particular device device coordi nates Provide display resolution independence normalized or virtual device coordinates Allow the user to work in a system that reflects their world world coordinates Allow users to move scale or rotate images easily with out recalculating the placement and size of the image modeling transformations Device coordinates DCs are the coordinates used to write to a device For the X Window System device coor dinates are defined in pixels Virtual device or normalized device coordinates NDCs provide a means to gain independence from the resolution of the display This coordinate system maps the width and height of a display to the coordinate range from 0
34. at HP Software Engineering Systems Division see the article on page 39 The objective of the collaboration was to design a user interface for HP start backup Interstate wis Transition return NULL return Current State 4 Current State Fig 9 Intrastate transition diagram for single action states These states are substates of the current state shown in Fig 7b IVIBuild that was both attractive and intuitive to the user Besides the appearance HP IVIBuild is structured to han dle native language support and user customization One other interesting feature is that the HP IVIBuild user inter face presentation is not bound to the functionality until run time Native Language Support and Customization HP IVIBuild s user interface conforms to HP standards regarding support for native languages and cultures All text that is presented to the user such as labels prompts and error messages is contained in message catalogs and is retrieved by HP IVIBuild at run time To localize HP IVIBuild the user only needs to change the contents of the catalogs In general these tasks are performed by HP per sonnel in the country whose native language is the target language This way text can be presented with as much context sensitivity as possible Idiomatic nuances of text presentation are not lost as they sometimes are with straight translations Another feature of HP IVIBuild s user interface presenta tion is th
35. bits of the selector defines the offset of the category to which that message belongs in the class s category table The lower 16 bits defines the offset of the method function pointer in the method table If the value of a particular position in the dispatch table is NULL the messaging routines traverse up the class hierarchy searching for a method function pointer When a function pointer is found it is copied to the position in the dispatch tables where the upward traversal of the class hierarchy began This tends to improve the performance of the messaging system over time because the amount of upward searching is slowly replaced by direct function calls and the NULL values in the dispatch tables gradually disappear Also the implementation of categories im proves memory use by eliminating method tables when a class does not support that category Polymorphism The concept of polymorphism in object oriented programming enables different types of objects to share a com mon operational interface and to be manipulated by user code independent of the actual types of objects This means that the application program does not have to differentiate the object type at run time This differentiation is performed automatically by the messaging system For example a message to a clock object to display the time would redraw the hands in a particular position if the clock were drawn as an analog clock while the same message would cause the time to be
36. busy working on HP OSF Motif Our users will see their work every time HP IVIBuild displays its user inter face Thanks to everyone who gave us their comments and encouragement Copr 1949 1998 Hewlett Packard Co Creating an Effective User Interface for HP IVIBuild The HP IVIBuild user interface was a collaborative effort between the software engineers developing the code for the product and a group of industrial designers who understand the requirements of an effective graphical user interface by Steven R Anderson and Jennifer Chaffee HP s computer systems are companies that are in creasingly integrating computers into their manu facturing processes However the computer focus of these companies is more on solutions than on hardware and software development To help provide these solutions on HP computer systems there are efforts within the company to encourage or enable independent software vendors ISVs to develop these software solutions HP IVI from HP s Industrial Applications Center IAC is one such effort Its purpose is to help ISVs build graphical user interfaces for their applications used in industrial applications Why the need for a graphical user interface Many of the operators and users of computer based systems in an indus trial environment are not computer literate They typically perform tasks like controlling an automated spray paint line and the interfaces to the tools they use are typically knob
37. commented out in Fig 10 were already successfully executed Test cases three and four were created by a second pass of the test generator based on the previous tests The test generator generates cases to trigger external events messages from the application or device by creat ing a message from the values involved State event pairs WAIT ACK and WAIT NAK Fig 9 were successfully generated because the test generator was able to use the structures ReplyAck and ReplyNak as the basis for triggering the events The test generator generates cases for internal events based on the associated values of the constants or variables involved If the values will satisfy the event the case is generated If not the case cannot be generated Each case is rechecked on every pass to see if the variables involved have been changed in previous test runs For more complete automatic test coverage the PSL program variables can be set to values favorable for test case generation In some cases the contents of the messages in the actions command file must be altered to affect subsequent cases The test exerciser Fig 11 starts the interface under con trol of the run time facility using the test configuration file Fig 12 and executes the test actions At the conclusion of the test the interface is terminated and the results are stored for examination Fig 13 shows the comparison results file The expected state event pairs for the expected results an
38. frequencies while the aluminum doped M phase strontium ferrite will satisfy the requirements at the higher frequencies Although it is possible to dope M phase barium ferrite with aluminum to raise its resonant fre quency and dope M phase strontium ferrite with scandium to lower its resonant frequency in general the higher the doping level the more the Q of the resonator is degraded Therefore dopants and materials are chosen so that the Hs Fig 4 Uniaxial anisotropy in hexagonal ferrites 60 HEWLETT PACKARD JOURNAL OCTOBER 1990 least amount of dopant is used to cover a given frequency range Other desirable properties of M phase hexagonal ferrites are that they have high 47M 3 for good coupling to the RF fields high Curie temperatures for low sensitivity to temperature change and fairly high Q 40 T 4 CES u 170 t n t E Fig 5 Anisotropy field changes with doping Adapted with permission from reference 4 Copr 1949 1998 Hewlett Packard Co Sphere Production and Test Once the selection of the M phase hexagonal ferrites was made and it was found that crystals were unavailable com mercially a crystal growth program was begun at the HP Microwave Technology Division In the literature hexag onal ferrite crystals are typically grown from a BaO B O flux using slow cooling We used a slow cooling furnace with multiple small crucibles per run and free nucleation no se
39. in file Device xx tr and filo Device xx da Event Path taken and Case Status in fle Device x tr IDLE reply message DCIO DCIO IDLE Case Status 0 Event Path taken and Case Status in file Device xx da IDLE reply message DCIO DCIO IDLE Case Status 0 Fig 13 Comparison results file Execution Number Number 1 Runtime Name Device xx Trace Data Available Action Command WURA Protocol Message Transmission Elapsed Time Thu Apr 13 14 33 30 1989 Protocol Message Data Packet 000 012000 Status Triggered State IDLE Event send message Variable Retrieval Elapsed Timo Thu Apr 13 14 33 30 1989 State Variables ReplyPacketdata RepiyPacket status 0 ReqPacketdata ReqPacketcmd 0 ReqPacket dst 10 DataPacketbcc 0 DataPacket data DataPackettns DataPacket sts DataPacket dst Text Fig 14 Trace data output file Copr 1949 1998 Hewlett Packard Co e oo BELL 6 Channel Multiplexer Fig 15 Configurations for HP DIS built interfaces One protocol interface handles one port and one device b Three protocol interfaces work together c Three protocol inter faces each dedicated to a port with an upper level interface 4 directing and organizing messages connected HP UX message queues HP DIS handles the message buffering This decreases development time since port configuration and buffer
40. lives in Campbell Califor nia He enjoys family activities reading mysteries and photography Software development en gineer Gary Thomsen who Joined HP s Data Systems Division in 1979 helped design widget classes lor the HP project Before that as an R amp D software engineer he provided sup port for the HP 1000 Series Forms 1000 product and as an R amp D product design engineer he designed the HP 1000 Series A hardware packaging Gary earned his BA degree in mathematics from San Jose State University in 1977 He is married lives in San Jose California and enjoys softball biking and woodworking 32 ZHP IVIBuild Steven P Witten The principal architect of the HP IVIBuild portion of the HP interactive Visual In terface Steve Witten im plemented the state chine and window and model handling for the proj ect Now an R amp D engineer at HP s Industrial Applica tions Center he joined HP s Data Systems Division in 1978 Initially he worked on Datacap 1000 and supported HP 307x termi nals and then developed an energy management system for HP using the PMC 1000 system Before joining HP he worked for Environmental Research and Technology Inc where he compiled a data base of airborne sulfate particulate measurements for the Electrical Power Research Institute s study of acid rain Steve is a frequent contributor to INTEREX the HP users group writing technical ar ticles on object
41. management code does not have to be written However the performance of this port interface will fall short of a similar interface with integrated port management functions It is also relevant that HP DIS is an HP UX application An HP UX cell controller whether written in HP DIS or in C is subject to normal HP UX timesharing policies and will have nondeterministic response times With HP UX on HP 9000 Series 800 computers processes can be run under a real time priority to decrease the chance that a Multiplexer Loopback Ports Fig 16 HP DIS performance test mode for multiple ports PModel is a simulated HP DIS application process will be preempted HP DIS uses this HP UX exten sion With real time HP DIS processes response time vari ability can be decreased Performance Test Results HP DIS performance studies were conducted to answer these questions w What is the performance HP 9000 Series 300 and Series 800 computers w What is the throughput of an HP DIS interface The flexibility of HP DIS allows device interface modules to be configured and combined in an infinite number of ways A simple model was chosen that gives representative data involving the major items contributing to performance Fig 16 depicts a typical configuration An application PModel is connected to a device interface module P11 which is connected to an HP UX RS 232 multiplexer port The port has a physical loopback connection and
42. manipu lated Attributes and Arglists Associated with API objects are attributes that describe properties of these objects Examples of object attributes include properties that define appearance characteristics such as colors and fill patterns for graphic objects and font highlight area and 3D shadowing for widget objects There are also coordinate system attributes that control the position and sizing of objects including their point height width scale rotation and translation Table I lists the categories of API attributes There is a specific list of attributes assigned to each API object type Users can set these attributes to desired values or can query the values contained in them through a data structure called an Arglist An Arglist is a variable length array of attribute value pairs The following is the C structure declaration for an attribute value pair struct ZtArgListStruct ZtAttributeType ZtAttribute ZtValueType ZtValue k typedef struct ZtArgListStruct ZtArgListltem where 1 r ZtAttribute is the defined attribute kj ZwWalueTypeis defined as a pointerto a P variable containing the attribute value x Arglists are used to define attributes of objects or functions Some of the advantages of using Arglists include 8 Arglists free users from fixed parameters in a function call The number of attributes that the user can pass as param eters can vary The number of function calls can
43. model used for simulation accurately reflects the behavior of the device or system being designed Engineers at HP s Colorado Integrated Circuits Division wanted to verify the accuracy of the electrical models of a 408 lead multilayer ceramic package for a large Integrated circuit chip The models were made up of discrete inductances capacitances and resistances To verify the models these parameters had to be measured on a real package When traditional high frequency measurement methods proved inadequate new methods were developed These methods are the subject of the paper on page 73 In integrated circuit design the objective of simulation is sometimes to predict in the design phase the statistical distributions of a circuit s performance parameters in production A problem is that IC parameter variations aren t all completely random as they are assumed to be by commercially available circuit simulators Those within a chip such as side by side resistor values are highly correlated and failure to take this into account leads to inaccurate simulations In the study reported in the paper on page 78 this problem was solved by applying principal component analysis a branch of multivariate statistics Each circuit parameter was expressed in terms of a set of independent random variables The independent variables were then used as the inputs to the circuit simulator program and the results were later converted to circuit parameter data Anothe
44. more natural manner The main concepts of this methodology include objects messaging polymorphism and inheritance Objects An object is the basic unit in object oriented methodol ogy It is a structure that contains local data structures and refer ences to local procedures called methods that operate on the data see Fig 1 The current values of an object s internal data define the object s current state The object s behavior is depen dent on its current state The data inside an object is private and accessible only through one of the methods associated with the object An object acts on its data when it receives a request asking one of its methods to perform some operation This mech anism is called messaging Objects are created from a template called a class There can be many objects of each class These objects are called in stances of the class Each instance is an independent object with its own data and state However an object instance has the same data structures shares the same methods and behaves the same way as all other instances of the same class This means that objects of the same class will respond to the same messages differences in object behavior depend on the current state the values of the object instance s data For example all object instances of an object class that draws rectangles will respond in the same way to a request to draw a rectangle How ever because of differences in the state of the inte
45. of HP micro wave spectrum analyzers and a magnetically tuned pre selection filter to remove unwanted signals The preselec tion filter uses barium ferrite resonator material doped so that it starts resonating at the beginning of the waveguide band see article page 59 Table I lists the four preselected RF sections and their frequency ranges Each RF section covers a full waveguide band 20 bandwidth one of the four standard bands from 26 5 to 75 GHz The HP 11974 Series preselected mixers are compatible with the HP 8566B spectrum analyzer the HP8563A port able spectrum analyzer the HP 70000 modular measure ment system with the HP 70907B external mixer interface module and other HP microwave spectrum analyzers They provide a displayed average noise level at 10 Hz bandwidth that is lower than 106 dBm in the A Q and U bands and lower than 95 dBm in the V band Image rejection is better than 55 dB in all four bands T HE NEED FOR HIGHER PERFORMANCE has driven Table I HP Millimeter Wave Preselected Spectrum Analyzer RF Sections HP 11974 Series Preselected Mixers RFSection Waveguide Frequency Band Range HP11974A A 26 5to40 GHz HP11974Q Q 33to50 GHz HP11974U u 40 to 60 GHz 11974V 501075 GHz Methods Extending the Frequency Range There are three principal ways to extend the frequency range of a microwave spectrum analyzer The first method shown in Fig 1a uses a classic superheterodyne
46. of solid color could be used This was a significant breakthrough With the capability to use color we added three colors to the black and white By using light middle and dark versions of a color we could make a button look very three dimensional This was achieved by making the top and left edges light the flat surfaces the middle value and the bottom and right edges dark This technique makes it appear as though a light is shining on the button from the upper left Another nice by product of this technique is that by momentarily switching the light and dark colors when a button is selected it actually appears to be pushed in It was so effective that people got a little silly pushing buttons the first time they saw a working prototype People intuitively grasp the notion that if something ap pears to protrude it can be pushed or selected to generate some action Widgets that accept or display inputs appear to be recessed Noninteractive things like labels are flat Convert Converted DOS file will be displayed in Al J10 Convert From 005 File File Name enter text here Scrollbars are hybrids with a recessed groove containing raised controls Menu bars look like large buttons with several labels on them When the mouse drags over a menu item it appears to raise transforming itself into a button When a menu item is selected by releasing the mouse but ton the feedback mechanism is th
47. of this the HP 11974 has switches that are used to identify the spectrum with which it is to be used For each switch setting a specific gain and offset are applied to the tune voltage so that the filter will be properly tuned Another requirement for the tune voltage of the spectrum analyzer is that it have a variable offset summed in The correct amount of offset to apply at any given frequency is determined by the preselector peak function Before operating the HP 11974 with the spectrum analyzer for the first time two potentiometer adjustments must be made These adjustments match the tuning volt ages provided by the spectrum analyzer to the reference voltages in the HP 11974 After these adjustments are made the preselector filter will track very well the input fre quency of the spectrum analyzer The preselector peak function is used to eliminate the remaining frequency track ing errors at any given frequer When executed this function causes the spectrum analyzer to vary its tune volt age to the HP 11974 and monitor the signal level of the marked response on the screen At the maximum response level the filter has been peaked The frequency range of the preselector peak function is proportional to the har monic number on which the mixer operates For most of the analyzers the preselector peak range is 260 MHz in Fig 17 11974A QIUIV pre selected millimeter wave RF sec tions with main
48. pro gram using the API calls to call up and activate the windows and other objects created with the builder An application s user interface can be constructed without the assistance of HP IVIBuild but with it productivity is greatly increased by the ability to create the interface interactively HP IVI is also one of the few products to combine at the builder level the power of a graphical presentation with the flexi bility and interactivity of widgets e g pushbuttons scrollbars and toggle buttons This article describes some of the market research and the target customers for HP IVI and provides an overview of the two main components of HP IVI HP IVIBuild and the application program interface N THIS AGE OF INFORMATION creating effective user Market Research The main customers of HP IVI are software engineers who build industrial applications This includes system integrators independent software suppliers and end users with internal software engineering groups These users benefit by being able to customize screens to their custom ers applications and by being able to reuse the symbols they created and saved in previous applications HP IVI also buffers its users from having to know the details of the intrinsics of both the X Window System and widgets This is considered to be a benefit and a boost to productiv ity Market research indicates that manufacturing applica 6 HEWLETT PACKARD JOURNAL OCTOBER 1990 tion
49. pulse rise times that give the same answer for the value of the tested ele ment In this and all the other test situations the test jig param eters must be measured without the package and subtracted from the values obtained with the package in place The design of the test jig is important and must include matched impedance lines with connections as close as pos sible to the PGA to minimize the parasitics of the test jig Good ground integrity is important since large parasitics can be introduced quite easily Poor connections are easily found using the real time display of the oscilloscope Move ment of a poor connection will produce corresponding wiggling of the oscilloscope trace and a poor connection can usually be located quickly and corrected Once the test jig and cabling are connected properly movement of the cables should produce no noticeable movement of the os cilloscope traces This troubleshooting ability is another benefit of this technique Inductance Measurement Inductances are measured by applying ramped currents instead of ramped voltages to the traces under test This is arranged by shorting the wirebonds of the PGA traces to the PGA ground circuit This circuit is shown in Fig 4 Rscope 2 Channel 2 o 10 40 50 20 Time ns Fig 3 Capacitance measurement circuit and voltage wave forms The input impedance of the signal trace represented by L in series with R is low compared wit
50. receiver front end A tracking preselector and a local oscillator LO both sweep the same frequency span separated by the in termediate frequency IF The preselector prevents spuri ous responses such as images or intermodulation products from being displayed The LO must be phase locked and have reasonably low phase noise To use this method high Q resonators and active devices maintaining negative resis tance across the full waveguide bands would have had to be developed The design would have been intricate and expensive These technological difficulties eliminated this method from consideration for the HP 11974 Series Fig 2 shows where this type of millimeter wave extender would interface with the mainframe microwave spectrum analyzer A block down converter shown in Fig 1b eases the local oscillator problem by using one fixed oscillator per band instead of the swept LO of the superheterodyne re ceiver With this down converter input RF frequencies are converted to an identical but lower frequency span swept IF The swept IF can be arranged to be within the range of the microwave spectrum analyzer Even though the res onator and the active devices are operated at a single fre quency designing for performance and cost still poses a formidable problem Also this method lacks a tracking preselector so the first mixer is subject to distortion caused OCTOBER 1990 HEWLETT PACKARD JOURNAL 49 Copr 1949 1998 Hewlett P
51. resonator material barium ferrite and a new four sphere design are featured in a series of magnetically tunable preselection filters for the millimeter wave frequency range by Dean B Nicholson Robert J Matreci and Michael J Levernier the frequency ranges of systems and components from the microwave range under 30 GHz into the millimeter wavelengths 30 to 100 GHz Moving to higher frequencies makes it possible for example to increase the antenna gain of small reflectors and to improve the spatial resolution of imagers The benefits of the move to milli meter wave bands are being felt in many fields especially communications remote sensing and defense The spectrum analyzer a calibrated receiver with vari able resolution is an important basic tool for testing and troubleshooting such systems Microwave spectrum analyzers use advanced technology to provide accurate unambiguous frequency domain measurements Hewlett Packard has extended these measurements into the mil limeter wave bands A new series of preselected spectrum analyzer RF sec tions the HP11974 Series preselected mixers makes milli meter wave spectrum analyzer measurements faster and easier by removing image and multiple responses from the spectrum analyzer display thereby eliminating the need for complicated signal identification routines Each RF tion consists of a mixer to down convert millimeter wave signals into the intermediate frequency range
52. senting user oriented objects that display crucial informa tion such as liquid levels and temperature The widget primitives e g pushbuttons scrollbars and text edits are also visual objects However unlike the graphics primi tives widget primitives can receive keyboard input as well as mouse input The widget primitives are used for display text editing and input and selection capabilities Primitive objects have no children Composite Objects These objects provide the means to organize and manage other objects Specifically composite objects make it possible to group primitive widget objects and other composite objects so that they can be manipu lated as a single object A function or attribute specified for a composite object affects its children without actually changing them For example erasing or redrawing a row column object will cause all its children to be erased or redrawn automatically Low Level Objects These are objects that are not directly visible like primitive or composite objects They are stand alone objects that are used to specify attribute values for primitive composite or high level objects Low level ob jects are used to set attributes for the other three object groups apply API functions to a list of objects or deal with user input from the activated objects High Level Composite Primitive Low Level Objects Objects Objects Objects System Menu Widgets Callback Server Menu Pane Image C
53. software de sign technologies and blend the best of each into the feature set and design of the application program interface API functions In doing so the project team investigated win dowing graphics the X toolkit Xt Intrinsics widgets and object oriented design This article discusses the features used from each of these technologies and how these fea tures are incorporated into the internal design and im plementation of the API functions see Fig 1 Windowing To hide the complexities of the X Window System from HP IVI application developers the API provides a layer of simplifying software over X The only X features left exposed are those that we thought the application de veloper must have access to or that cannot be layered over Even with this layer of software the user still has access to X functions For example X provides an event called ConfigureNotify that tells the application that a window has been resized moved or changed in some way The API handles resizing the window object when this event occurs but lets the application decide if all the objects in the win dow should be resized to match the new window s size or if the objects should maintain their sizes and only the coordinate system of the window should be adjusted The user still has direct access to the X functions if they are needed The API also ensures that all X events e g a mouse button press and release that occur in a window object
54. state ending up at the top of the stack is started If the autotermi nation flag is FALSE only an action by the user can terminate the state State Transition and Inheritance As mentioned earlier an interstate transition is the pro cess of making a new state a state not currently on the state stack the current state The new state is placed at the top of the state stack and started by the state machine The state transition process begins when an event occurs such as a button release over an object on the display The first thing to happen is that the state machine function is called as part of the normal API callback processing see page 23 The state machine function is passed a pointer to the ZIUSER DATA attribute of the object that received the event which has a pointer to the message selector that when sent to the current state will cause an interstate transition to a new state The state machine sends the message to the current state This process works the same way for HP IVIBuild user interface objects and user workspace objects except that user workspace objects always send a hit mes sage to the current state A window created by the user is theonly user workspace object that functions like a user in terface object A hit message results when a user presses a mouse button in a workspace window If the current state can handle the message the method that is called will either return a pointer to the current state or a NU
55. state diagram for a parity checker References 1 P Denning J Dennis and J Qualtz Machines Languages and Computation Prentice Hall 1978 2 AS Tanenbaum Computer Networks Second Edition Prentice Hall 1988 Figs 7a and 7b show state diagrams derived from the transition diagrams The states and events form the logic of the protocol interface Actions or funciions are per formed at each state event pair Fig 7a also shows an event retry exceeded that is not supported by the transition diagram This event is added to prevent endless looping A message from the device to the computer Fig 7b will cause a reply message event which would normally return directly to the IDLE state This example will check the integ rity of the byte stream by checking the BCC block control character count and branching to an extra state CHECK If the BCC count was incorrect the original message will be sent back to the device If the BCC count was correct the message from the device will be returned to the appli cation The combination of the IDLE state and the reply message event is included in case the device sends a mes sage after time out processing If this were not included the wrong message would be extracted from the HP UX message queue during the next transaction The message from the device is simply acknowledged and ignored OCTOBER 1990 HEWLETT PACKARD JOURNAL 65 Copr 1949 1998 Hewlett Packard Co Tabl
56. the list but retain the objects free the point list point list in the example above int return_val static ZlArgListltem recursiveArglist ZIRECURSIVE NULL ZiValueType TRUE ZiValueType NULL free the list and its references the two point objects recursiveArglist 0 ZtValue ZtValueType TRUE return val ZtFree point list recursiveArglist free the list but leave the two point objects alone recursiveArglist 0 ZtValue ZtValueType FALSE return_val ZtFree point list recursiveArglist Bookeeping Three API functions are provided for retriev ing information about list objects These functions include m ZiCheckListObject for verifying the presence or absence of an object in a list m ZtCountList for counting the number of objects in a list m ZtGetListindex for determining the position of an object in a list Extraction An object can be extracted from a list of objects by invoking ZtGetListObject and specifying the index of the object or by using the function ZtGetListTail to extract the last object in a list Insertion Objects can be inserted into a list by using m ZiinseriListindex to place the object at a specified index m ZtinsertListObject to place the object before an object with a known identifier m ZtinsertListTail to place the object at the end of a list These functions can be used to add an object to the child lists of windows models or composite objects The follo
57. the principal components The values for the x in equation 1 are chosen randomly and independently This is possible because the x are statisti cally independent The in equation 1 are the eigenvalues of R The u and a are the mean and standard deviation of the ith variable Yy is the jth component of the ith eigenvector of R The statistical measures for these variables are obtained from volume manufacturing data Circuit Simulation Algorithm A circuit simulator was written in C and HP UX scripts Itruns onan HP 9000 Series 370 workstation The algorithm of this program is shown in Fig 1 It consists of three modules A statistical analysis package performs all the computa tions according to equation 1 A parser retrieves these correlated vectors and generates the HP Spice text files HP Spice performs the simulations The user is required to input three pieces of information 1 the HP Spice text file 2 the correlation matrix of the circuit variables and 3 the means and standard deviations of the circuit variables Data for 2 and 3 has been com piled from volume production measurements for many HP fabrication processes The confidence limits of the simulated distributions vary as the square root of the number of simulations Based on numerous case studies about 100 simulations are adequate to project a 95 confidence limit even for a fairly complex system Although these Monte Carlo simulations are c
58. the rankings is shown in Fig 2 In most cases we had to derive the secondary or tertiary need From here the features were placed on a tree diagram to ensure that there were no gaps and to guarantee that we had met all of our customer needs During data collection each of the customer needs should be given an importance rating However our collectors had not been trained before going to the customers and so they did not collect the importance rating with the murmurs The team as signed the ratings during analysis The next step was to develop methods for delivering customer needs This was done with knowledge of what could be done with software These became our implementation methods For example if a customer needed a window to display alarm infor mation quickly this translated into choosing a system that could rapidly retrieve and display data in windows such as the X Win dow System Each implementation method was analyzed to determine il it hada strong medium or weak relationship to satistying customer needs This formed the relationship matrix see Fig 3 Symbols are used in the matrix to indicate the relationship between cus tomer needs and implementation methods If no symbol is placed on the matrix then the implementation has no relationship to satisfying customer needs This graphic representation is very useful One can look at the matrix and see the areas that cover the customer needs and the areas that require more atten
59. the same side of the Voo wirebonds as shown in b In actual service the wirebond pattern is as shown in a This accounts for most of the difference between the measured and calculated values Copr 1949 1998 Hewlett Packard Co Vp Measurement Errors The wirebonding pattern may vary in the Vp bonds In the calculations for the inductance we also did not take into account the inductance of the epoxy routing on the chip The power trace capacitance measurements were done without the bypass capacitors because the 0 1 4F nominal value of the bypass capacitor is very large compared to the capacitance parameter that we were trying to measure A very high degree of correlation was obtained between mea surements and calculations Conclusions It is important to be able to verify electrical models of packages used in high performance systems Time domain reflectometry cannot give the kind of detail needed for model verification and it is very difficult to derive an RLC circuit from the results The measurement technique described in this paper overcomes the problems associated with TDR measure ments Inductance is measured while capacitance is shorted out and capacitance is measured on open circuit traces so inductive effects are negligible Slow rise times of input voltage pulses make it possible to avoid transmis sion line effects A feature of this method is that the mea surements can be made with readily available dig
60. thing An example of this are selections i e states that select certain kinds of objects for further operations Once the class of objects that are to be selected is known the objects are selected and no further input from the user is required Any single action state that receives a hit mes sage is terminated and removed from the state stack The hit message is sent to the the new current state Fig 9 shows the intrastate transition diagram for all single action states Backup All multiaction states implement backup This is the reverse operation of a hit message because it allows the user to cause the action of the state to go backward over a previously sent hit No single action states implement back up Undo All states implement undo Undo allows the user to back a state up to the point right after it received its first start This has the effect of undoing any actions that had been performed by the state Undo may also be sent im mediately after a previous undo to effect a redo operation Exit A state is sent an exit immediately before its removal from the state stack This allows the state to reinitialize start backup Interstate undo Transition hit return Current_State return NULL exit Fig 8 intrastate transition diagram for a multiaction state that translates objects These states are substates of the cur rent state shown in Fig 7b Copr 1949 1998 Hewlett Packard Co itself for its n
61. to bring the X Windows technology to the factory floor The combination of widgets and graphics gives the application designer more freedom to present the needed information in the fashion best suited for its in tended viewers This design freedom promotes the kind of informed decision making needed in today s fast paced and highly competitive industrial marketplace References 1 D L McMinds and B J Ellsworth Programming with OSF Motif Widgets Hewlett Packard Journal Vol 41 no 3 June 1990 pp 26 35 Copr 1949 1998 Hewlett Packard Co The HP IVI Object Oriented Toolkit Using object oriented design techniques a minimum set of functions is provided with the HP IVI product for manipulating widgets and graphic objects to create a graphical user interface by Mydung Thi Tran and David G Wathen HE HP IVI APPLICATION PROGRAM INTERFACE API is an object oriented toolkit of C functions that enable a software developer to create an interactive and informative graphical user interface programmatically The API functions can be used for any application in which a highly interactive graphical user interface is required The collection of API functions provides the ability to build different models of user interfaces that can be saved and used again in other user interfaces High level objects pro vide the control and organization necessary to support lower level composite and primitive objects All objects have configur
62. 0 to 1 0 Normalized device coordinates define a viewport A view port is a rectangular drawing region on the display surface Specifying the viewport in NDCs maintains the ratio be tween the drawing area and the display size regardless of the display resolution World coordinates provide a user defined coordinate system This system allows users to create pictures using the most appropriate coordinate system for the task For example if the world coordinates represent the physical dimensions of a factory using the dimensions from a blue print of the factory to create a picture is straightforward World coordinates define which area of the unbounded User Application API Functions API Internal Technologies Graphics Windows Widgets Xt Intrinsics Object Oriented Design Fig 1 The software technologies incorporated into the inter nal design and implementation of the HP IVI application pro gram interface API OCTOBER 1990 HEWLETT PACKARD JOURNAL 21 Copr 1949 1998 Hewlett Packard Co world coordinate space is visible in the viewport This type of coordinate system also provides viewport size indepen dence and display resolution independence since the world coordinates remain the same regardless of the phys ical size or resolution of the display Modeling transformations allow the user to define a slightly different view of the world coordinates for each piece of the picture Modeling transformatio
63. 64 h static ZtArgListltem textArglist ZIHEIGHT ZIWIDTH ZWalueType amp h ZWalueType amp w ZIPONNT ZiValueType NULL ZISTRING ZiValueType NULL NULL ZtValueType NULL text height 4 textwidth 218 for point text string k arglist for point object static REAL64 x y static ZtArgListltem pointArglist I zx ZtValueType amp x zY ZiValueType amp y NULL ZiValueType NULL create reference pointfor objects 7 10 0 10 0 pointld ZtCreate ZtPOINT OBJ pointArglist NULL setuptocreate first text object with height 20 and width 40 h 20 0 w 40 0 textArglist 2 ZtValue ZtValueType pointld textArglist 3 ZtValue ZtValueType First text object create the first text object text Id ZtCreate ZtTEXT OBJ textArglist NULL change point components I y 60 0 return val ZtChange pointld pointArglist NULL create second text object at 10 0 60 0 textArglist 3 ZtValue ZtValueType Second text object text2_Id ZtCreate ZITEXT_OBJ textArglist NULL freepointobjectifitis no longer needed 7 ZtFree pointid NULL Instead of calling ZtCreate twice the function ZtClone can be used to create the second text string object 14 HEWLETT PACKARD JOURNAL OCTOBER 1990 Text Objects ZrTEXT OBJ Point Objects text dd ziPOINT OBJ ZSTRING Second Text Object
64. April 1988 p 28 2 Hewlett Packard Journal August 1990 pp 6 60 3 C Jue A System to Develop Factory Floor Device Interfaces Proceedings of the Third International IMS Conference Vol 3 part 1 September 1987 pp 134 146 Copr 1949 1998 Hewlett Packard Co Measurement of R L and C Parameters in VLSI Packages Developed to verify the electrical models of a 408 lead multilayer ceramic package this measurement technique can measure the very small inductances capacitances and resistances that are typical of high performance packages It does not require extraction of RLC parameters from time domain reflectometer measurements by David W Quint Asad Aziz Ravi Kaw and Frank J Perezalonso count IC packaging with a large number of I O con nections has brought about a project to design and characterize a multilayer ceramic PGA pin grid array ca pable of providing up to 320 I O lines at an operational frequency in excess of 60 MHz Our challenge is to produce a package that brings the performance advantages of mul tilayer cofired ceramic technology to high lead count high power VLSI circuits The package currently in development will mount a 14 mm square CMOS chip Fig 1 is a cross sectional drawing of the package The package contains 12 metallization layers which are used for signal power and ground routing and uses three tier bonding from the chip to the bonding pads on the package The top two b
65. Constant byte bt variable string str2 and the message received is aabbBddBd HP DIS uses a first shortest match algorithm to parse this as stri aabb b B str2 ddBd vi uses a first longest algorithm The vi command typed in as s NBI y stri 2 2 would result in stri and stre matches as stri aabbBdd str2 d Testing The tests test scripts and results files can be gen erated automatically at compile time with a PSL compiler option The tests are executed from a test script and the results appear in several data files The action command file contains the test actions to be performed The comparison results file contains a summary of the test paths The trace data output file contains detailed test flows and variables The test generator walks the state table and generates the actions command file Fig 10 The test generator starts with the first state event pair in the PSL program and gen erates commands to trigger the event The test terminates at the state and event in the ECASE statement last state next state event of last state The data following the WURA write to upper level read area statement is the equivalent of a message from the application The data following the WLRA write to lower level read area statement is the equiv alent of a message from the device A test case is generated for each subsequent state event pair The test cases CASE 1 and CASE 2 marked Good and
66. Jennifer s profes sional interests include the visual design ot com puter user interfaces Born in Fort Worth Texas she lives in Sunnyvale California She enjoys paint ing pastels pottery making backpacking travel ng and photography m 49 BaFe Proselected Mixers Michael J Levernier Development engineer Mike Levernier was respon sible for the design of the HP 11974 filter drive cir cuilry and for HP 11974 test development He joined HP s Signal Analysis Divi sion in 1984 as a manufac turing engineer respon sible forthe HP 8557A and HP 8559A spectrum analyzers Following that he worked on the microwave and RF front end mod ules of the HP 70000 modular spectrum analyzer family He also served as an HP regional sales de velopment engineer Mike received his BS degree in 1983 in electronic engineering from California Polytechnic State University San Luis Obispo and his MS degree in 1986 in electrical engineering from Stanford University Born in Sacramento California he lives in Windsor California His hob bies include windsurfing skiing and racquetball 46 HEWLETT PACKARD JOURNAL OCTOBER 1990 Copr 1949 1998 Hewlett Packard Co Robert J Matreci R amp D iab he dev sories for spei 11970 Series waveguide harm joining HP he developed avionics test equipment for weather radar Bob has authored two technical papers and is named an inventor on a patent re lated to the prese
67. LL drawatext object whetherornotithas been modified ZiDo textid ZIDRAW NULL drawalistofobjects other than low level objects 9 ZiDo listld ZIDRAW NULL raiseawindow ZtDo windowld ZtRAISE NULL lowera window ZtDo windowld ZtLOWER NULL Two modes of updating or drawing objects on the display are possible immediate update and deferred update In immediate update mode the windows are redrawn anytime there is a visual change in the objects In the deferred mode the process of redrawing windows can be postponed until an explicit update is performed through ZtDo ZtUPDATE or a change in the update mode This mode is useful if changes need to be made to many objects and it is only necessary to refresh the window once Both modes are activated by setting the system object s update attribute to either immediate or deferred The following code puts the system object in the deferred update mode update mode arglist for system object static ZtArgListitem updateModeArglist ZtDEFER_UPDATE 2tValueType TRUE NULL ZiValueType NULL k 2 systemld windowld int return val rowcolumnia ZIRECURSIVE Returned from ztrindByLocation FALSE rowcolumnid TRUE pushbuttonia Fig 5 Locating an object with ZtFindByLocation When mouse event happens over the pushbutton if the ZtRECURSIVE attribute is FALSE the identifier for the row column object rowcolumnid is returned If the ZIRECUR
68. LL This pointer is returned to the state machine as part of the normal message sending mechanism of the HP IVI object oriented environment States return pointers to themselves when they want to remain current This will cause an intrastate transition States return NULL when they receive an exit message and want to cease being the current state This will cause an interstate transition Fig 6 shows a portion of the state transition process Since the root state is the parent of all other states the interstate transition process depends heavily on inheri tance Each state inherits all the methods from the root state When a state receives a message for which it does not have a method the HP IVI object oriented environment will search the current state s lineage object hierarchy until it finds the target method for the message In the case of an interstate transition the target method will always be found in the root state The target method in the root state returns a pointer via the object oriented environ ment s messaging system to the state object that is to be made the current state This is the pointer that the state machine compares to the value of the pointer for the current state When it sees that the two pointers are different it Button Release y DzState Machine msg selector Event Send Message to Current State Interstate TD Transition Pointer Current No State Pointer Send star
69. NULL get the current childlist of Model 1 ret ZtQuery model1ld childlistArglist NULL if ret childitild Ztid childlistArglist O ZtValue add pushbutton pb1ld to the end of the childlist of model 1 ret ZtinsertListTail childlisti ld pb1ld amp childlisti ld if ret Change modeltid s childlist to include the pushbutton pb1ld The API automatically updates the childlist of model 2 ret ZtChange model1ld childlistArglist NULL 20 HEWLETT PACKARD JOURNAL OCTOBER 1990 Freeing Model or Composite Objects The counterpart of cloning model and composite objects recursively or nonrecursively is the ability to free these objects from the intermediate parent Take the case of an application in which one of its model objects has a row column object as one of its children Suppose the applica tion requires that the row column object be freed but the children of the row column object must remain The API provides an option in the ZtFree function that allows the user to accomplish this task Setting the ZtRECURSIVE attri bute in the function Arglist to FALSE and calling ZtFree on the row column object destroys the row column object and its children become the children of the model object In contrast passing a function Argiist to ZtFree with ZtRECUR SIVE set to TRUE will free the row column object and its children Symbols and Models Models can be created as children of other models A mo
70. P s Indus trial Applications Center in 1988 Mydung has au thored or coauthored five technical articles on distrib uted processing particle dosimetry space radia tion and nuclear track detectors Before joining she was a research physicist at the University of Califomia at San Francisco and a graduate as sistant at Lawrence Berkeley Laboratories A member of the ACM her professional interests in clude computer graphics parallel processing and networking She received her BS degree in physics in 1975 from the University of San Francisco and her MS degree in computer science San Fran cisco State University in 1989 Born in Saigon Viet nam she is married has a son and a daughter and ives in San Francisco User interface design graphics and artificial in telligence are the profes sional interests of David Wathen a software en gineer wha developed en hancements for the HP IVI project He joined HP s In dustrial Applications gt Centerin 1989 shortly after he received a BS degree in computer science and applied mathematics Irom the University of Colo rado at Boulder Before joining HP he was a solt ware designer for the National Center for Atmos pheric Research NCAR where he built an X11 window interface to NCAR graphics David was also an advanced interface intern at US West where he worked on future telephone projects Born in Littleton Colorado he resides in Sunnyvale California
71. Packet dst AB DataPacket bcc BocFlag CHECK WAIT timeout DeClock Stop_timer TimePeriod DcMove NoResponse ReplyPacket status DclO Wrie Applic write ReplyPacket IDLE WAIT retry_exceeded DoCiock Stop timer TimePeriod DcMove ComError ReptyPacket statusy DcIO Write Applic write Q ReplyPacket Result ADLE CHECK msg ok DclO Write Device Write ReplyAck Result DcMove StatusOK ReplyPacket status DcMove DataPacket data ReplyPacket data DclO Write Appiic write ReplyPacket Result ADLE CHECK msg nok DclO Write Device Write ReplyNak Result DeOntr increment RetryCount one DcCiock Start timer TimePeriod TimeOutVal WAT Fig 9 PSL Protocol Specification Language protocol program 68 HEWLETT PACKARD JOURNAL OCTOBER 1990 Copr 1949 1998 Hewlett Packard Co Action Routines HP DIS is shipped with a wide variety of routines to ease the creation of protocol interfaces If a required action routine cannot be found in the HP DIS action routine library the user can write a user action routine A protocol interface consists of two components a finite state machine and its corresponding internal tables The finite state machine is customized for the HP DIS and user action routines The internal tables are 1 an identifier table consisting of con stants and variables 2 an event table consisting of event IDs and event expr
72. SIVE attribute is TRUE the function searches for the primitive object in the area and returns the identifier for the pushbutton pushbuttonid Copr 1949 1998 Hewlett Packard Co atsome point in the application set update mode to deferred return val ZtChange systemld updateModeArglist NULL it is necessary to redraw one of the windows return val 2100 windowld ZIUPDATE NULL List Manipulation Functions The API list manipulation functions allow programmers to create and manipulate lists of objects Creating an Object List The following example creates list of two points using the function ZtCreateList see Fig 6 arglist for point object static REAL64 x static ZtArgListItem pointArglist ZIX ZtValueType amp x 21 ZtValueType amp y NULL ZtValueType NULL k Identifiers for pointer objects Ztld point1ld point2ld point list identifiers for pointer objects create a point at 50 0 50 0 x 50 0 y 50 0 pointtid ZtCreate ZtPOINT_OBJ pointArglist NULL create another point at 60 0 50 0 x 60 0 point2id ZtCreate ZIPOINT OBJ pointArglist NULL create the list for these two points point list ZtCreateList ZILIST OBJ point1id point2id NULL Freeing a List When the list of objects is no longer needed it can be freed The application has the option to free the list along with all the objects it references or to free
73. ST attribute set to the Ztld of the ZILIST OBJ created in the first step objecttid Fig 8 Merging lists The objects on list Mergeld are merged be tween the first and second objects of list Listld resulting in a new list Newistld OCTOBER 1990 HEWLETT PACKARD JOURNAL 19 Copr 1949 1998 Hewlett Packard Co 9 Repeat the first two steps until all the menu panes and menu buttons are created 9 Put all the menu panes into a list object 9 Create the menu object with the ZICHILD LIST attribute set to the newly created ZILIST OBJ from the previous step Reparenting In API it is not necessary to destroy all the objects created and start all over when the user wants to change the objects relationships Regrouping objects by changing relation ships is called reparenting The ZiChange function makes the task of regrouping very easy The new child list is simply passed to the desired parent object and the API lakes care of removing the targeted children from the old parent s child list and assigning them to the new parent For example the following code segment moves the pushbutton object PushButton 1 from Model 2 to Model 1 and inserts PushButton 1 into the child list of Model 1 Ztldpb1ld PushButtonild Ztld modeliid Modelild 2118 childlistt Id Modelichidlist INT32 ret ReturnValue static ZtArgListitem childlistArglist ZtCHILD_LIST ZtValueType NULL NULL ZtValueType
74. T Reference Voltage Spectrum Delay Analyzer impen Dependent Adjustable cod Gain and Offset ll Thee Thermistor x Network 5 posite is located the waveguide portion of the filter sembly Fig 13 and tracks the temperature at the barium ferrite filter The network has a temperature dependent resistance that is linear from 0 to 100 C The thermistor net work is connected as the feedback portion of an amplifier that generates a voltage equivalent to the amount of filter frequency correction required This voltage is then summed into the voltage that generates the filter coil current Although the temperature compensation required varies from band to band the filters of each band are very consis tent from unit to unit and across the frequency band This consistency allows the correction to be based on tempera ture only In the and Q bands the filter drifts lower in frequency with increasing temperature while in the U and V bands the filter drifts higher in frequency with increasing temperature Fig 15 shows the frequency tracking errors of a V band filter at 0 25 and 75 with no temperature compen sation applied The frequency tracking errors of the 25 trace represent the deviations from a linear relationship between the filter coil current and the filter frequency The spacing between the three traces represents the temperature drift of the filter with no temperatur
75. University with a BSc degree 1979 in mechanical engineering and has ME degree 1980 in fluid dynamics from the von Karman Institute in West Germany Born in Los Angeles California Kent is married has three chil dren and resides in Eagan Minnesota His hob bies include aircraft design and radio controlled sailplanes Since joining HP s Systems Technology Division in 1987 Vivek Mansingh has performed research and development in thermal management of electronic equipment in the com pany s mainline systems lab Using finite element A modeling he analyzed three dimensional air flow in the HP 9000 Model 850 computer Before joining HP Vivek taught at Lehigh University from 1986 to 1987 member of the ASME the IEPS and the CHMT he has au thored or coauthored 12technical publications on thermal fluids and is named an inventor ona pend ing patent He earned his MS and PhD degrees in 1986 from Queen s University in Canada studying mechanical engineering and specializing in ther mal fluids Born in Fatehpur India Vivek is married has two children and lives in Santa Clara Califor nia He enjoys traveling with his family and singing Indian music with a professional group His hobbies include jogging tennis and badminton 48 HEWLETT PACKARD JOURNAL OCTOBER 1990 Copr 1949 1998 Hewlett Packard Co 26 5 to 75 GHz Preselected Mixers Based on Magnetically Tunable Barium Ferrite Filters Anew
76. Xt Intrinsic Arglists The API Arglists are arrays of attribute and value pairs This feature frees the application from having fixed parameter lists that force it to make many calls The application also doesn t have to pass unnecessary parameters Parameters that it doesn t pass are automatically defaulted One deviation from the Xt Intrinsic Arglist is that the API uses a null termi nated list instead of a counted list The API also extends x y wc Modeling Transformations WC to e Song Transformation Translation Rotation Normalized Device World Coordinate WC Coordinate NDC System System meters grams Inches etc 22 HEWLETT PACKARD JOURNAL OCTOBER 1990 NDC to DC Transformation XtMainLoop Get Next X Event XINextEvent amp event button press Call Event xtDispatchEvent amp even F Processing Function Fig 3 The Xt Intrinsics XtMainLoop function the attribute default concept so that the application can change the defaults of different classes of objects at run time API Arglists are described in the article on page 11 Object Oriented Design HP is an object oriented system Object oriented de sign and object oriented programming are being increas ingly used at HP for software product development The goals of object oriented methods are very appealing be cause they encourage such practices as code reuse and functional cohesion o
77. able attributes or characteristics that make it possible to customize the look and feel of a particular ob ject Color size and font are a few examples of these attri butes The API functions allow a programmer to do things like create and free objects query attributes save and re store objects get input and find objects by location This article describes the the API functions and the arti cle on page 21 describes the internal design supporting these functions The API Object Hierarchy All the components of an API application are separate objects that are combined together in a hierarchical arrange ment to form a working user interface An example of this hierarchical relationship is shown in Fig 1 This relation ship is described in terms of ancestry For instance Model 12 in Fig 1 is the parent of three children Model 21 a rect angle and a row column object Another way of saying this is that Model 12 is the ancestor of three descendants Model 21 a rectangle and a row column object Every API object belongs to one of four groups high level objects composite objects primitive objects or low level objects Fig 2 lists the different API object groups High Level Objects These objects control and organize groups of objects and hold global resources that help define other objects in the hierarchy The high level objects must be created in a specific order system object server object window objects and model objects B
78. ackard Co Tracking ee Fundamental Mixer RF In a Fixed IF Out 50 to 75 GHz 321 MHz Swept LO 50 32 to 75 32 GHz Tune Sweep Ramp In RF In 50 to 75 GHz Wideband Preamplifier Ret Fixed LO 76 00 GHz b Harmonic Mixer 14 RF In E op IF 50 to 75 GHz z 4 4 321 MHz S 3 54 to 5 33 GHz 1 Ramp Fig 1 Three types of RF sections for extending the trequency range of a spectrum analyzer The letters A B C and D refer to Fig 2 which shows where these RF sections connect to the spectrum analyzer a The superheterodyne RF section uses a swept preselector and a swept local oscillator LO The phase locked loop is used to set the beginning of the LO sweep accurately b The block down converter has a lixed LO and a swept intermediate frequency IF c The harmonic mixer version of the superheterodyne RF section 50 HEWLETT PACKARD JOURNAL OCTOBER 1990 by multiple signals and even single input signals The wide span of the IF can cause another problem It requires a very wide bandwidth IF amplifier to improve the sensitivity of the microwave analyzer which is used as a variable IF strip The preselected harmonic mixer version of the super heterodyne front end shown in Fig 1c provides a reason able compromise The preselector protects the mixer from spurious responses The mixer a harmonic type uses a millimeter wave harmonic of the existing microwav
79. acteristics early in the design A model could also easily simulate effects of high The objective process altitude zero gravity of this study was to investigate the effectiveness of finite and other conditions element modeling in predicting the air flow and pressure drop characteristics within a computer Model Development As mentioned earlier a full scale model of an air cooled wing of a M ydel 850 SPL sapproximatels rawings showir 1ral components printed flow ere used to create the full scale model of the system using s preprocessor FIPREP and mesh generator FIMESH s divided into smaller finite elements s suction fans nlets and flow outlets The full model using 8 node brick elements Fig 2 gives a view of the final mesh ting of 60 507 nodes and 48 600 elements From the outset it was recognized that detailed three dimensional modeling from the system level to the compo nent level that is from the overall dimensions of the cabinet down to the smallest component on a board was possible both from a modeling standpoint and because of computation time requirements For instance we esti mated that simulating the flow through just one of the CPU boards having a number of RAM chips PGAs CPU chips and multifinned heat sinks would require a mesh of ap proximately 60 000 to 100 000 elements and a run time of more than 10 CPU hours Therefore it was
80. agnetically tunable bandpass filters that cover waveguide bands in the millimeter wave region using moderate magnetic tuning fields Fig 1 A class of material with this property is the hexagonal fer rites Properties of Hexagonal Ferrites Hexagonal ferrites are so named because this class of materials has a hexagonal crystal lattice which produces crystals that have distinctly hexagonal shapes Fig 2 The hexagonal ferrites have a large number of phases Fig 3 compares the parameters of the most important phases there are many more to YIG parameters 7 The most useful hexagonal ferrites have a property called uniaxial anisotropy Fig 4 which means that the anisotropy field ies along only one axis which is the C axis for the hexag crystal Hexagonal ferrites are commonly referred to by their phase and composition For example M phase barium ferrite is BaFe 20 9 The minimum useful frequencies listed in Fig 3 come from three constraints First with the anisotropy field aligned with the applied field equation 1 shows that the lowest frequency of resonance is 2 8 MHz Oe H with negligible applied field Second the magnetic dipoles in Fig 2 Hexagonal ferrite crystals OCTOBER 1990 HEWLETT PACKARD JOURNAL 59 Copr 1949 1998 Hewlett Packard Co Minimum Useful Temperature Dependence Curie Temp of Resonant Frequency Can be made Oto 277 firstorderby YsFe Ga
81. all data written to the port is immediately read back from the port Each port has one PModel A fixed length message is sent to the port by a PModel and returned unchanged Because the application program waits for each message to return before sending another only one message is in the loop at time per PModel Throughput data is averaged over 20 transmissions for various message lengths using one then i i 1000 2000 3000 bi Message Length Bytes H 3000 e 2000 1000 s 8 1000 2000 3000 Message Length Bytes Fig 17 Loopback response time for performance tests using the HP DIS application PModel on a HP 9000 Model 375 and b HP 9000 Model 832 computers HP DIS 2 2 on HP UX 70 OCTOBER 1990 HEWLETT PACKARD JOURNAL 71 Copr 1949 1998 Hewlett Packard Co two PModels Fig 17 shows the data throughput of an HP 9000 Model 375 and an HP 9000 Model 832 both with 16M bytes of memory under the HP UX 7 0 operating system The throughput in Fig 17 reflects the transfer of data one way The curves show the data throughput for one PModel and the sum of the data throughputs for two PModels The throughput decreases with message sizes above 1000 to 1500 bytes because HP DIS is performing message match ing see Matching Messages page 67 HP DIS matches raw byte streams to the user s definition of the message Summary The Hewlett Packard Device Interfac
82. and sized many of their physical attributes such as colors shadows strings and fonts can be changed easily within HP IVIBuild Even some one who does not have any software background such as human factors expert can use HP IVIBuild to design a Processing States Display Output State Machine API Functions HP IVI Object Oriented Environment X Window System Workstation To Display Hardware Fig 2 The components that make up the HP IVIBuild ar chitecture Copr 1949 1998 Hewlett Packard Co complex user interface This means that an application s user interface can be prototyped and evaluated separately from the operations performed in the application Besides restoring the user interfaces created with HP IVIBuild the API functions in the application also make the objects in the interface react to user input Callback functions which are invoked in response to user input to the application can be attached to those objects that should respond to user input If the application requires changes to the user interface in response to application or customer needs the previously saved user interface can be modified with HP IVIBuild If the changes involve adding new ob jects callbacks can be added to the new objects using the API functions in the application program However if changes are made to existing objects no changes need to be made to the application program Fig 3 shows the interface areas provi
83. are saved in a file and a user application uses the functions to retrieve and manipulate the objects Copr 1949 1998 Hewlett Packard Co HP IVI Project Management The HP Interactive Visual Interface project was a relatively large software project 100 KNCSS and as such it was faced with some interesting challenges during product development Besides the normal challenges associated with software project management e g version control code inspections project standards and schedule deadlines HP IVI was faced with three main challenges determining the exact customer needs before design and implementation using existing software and using new software development technologies For determining cus tomer needs a process called quality function deployment QFD was used This process helped us to determine the feature set for HP IVI see box on page 9 The existing software was a combination of software from other HP entities and from outside vendors Finally the new technologies included the use of objects and windows for design and implementation Existing Software One of the primary goals of HP IVI was to leverage the work of others The decision to use existing software resulted from the desire to decrease the time to market for the product by reducing the engineering time and effort involved in design implementa tion and support There was also a need to base HP IVI on components that conform to standards
84. asses are resolved By using object oriented technologies the API is able to create graphic objects One problem users have with soft ware systems such as the X library is that graphic primitives are not objects The X library provides many graphic func tions that operate on the individual pixels of a graphic display but the parameters describing the object are not kept For example if a circle is drawn and the application simply wants to change its color from blue to red all the parameters location size line width etc to draw the circle must be passed to the X library function again The API solves this problem by providing graphic objects using the rtc tool This allows the user to describe the parameters of the object once and then make simple modifications only to the parameters that are changing The application is freed from maintaining all of the data necessary to redraw all of the graphical objects in the window Conclusion The HP IVI project was successful in blending graphics windowing X toolkit widget and object oriented tech nologies in the internal design of the API Because most of these technologies were developed separately it was not always clear how to integrate them The API solved most of the problems encountered and as a result of this effort a high level user interface toolkit was created that reduces the complexity of building a sophisticated graphical user interface for an application jments Besides t
85. at an object s specific data and the functions that manipulate the data are accessed In essence the API hides from the user as much as possible the details of using objects To provide the interface between an application and its objects a preprocessor tool called nc run time class infor mation is used to define the API object messaging facility and class interitance hierarchy based on information from a group of description files Every API class consists of a class header file and a class definition file The class header file defines the data storage for each instance of an object of that class This file identifies the object as a member of a class or classes and provides the connection to the set of methods that manipulate that object s internal data The class definition file is a C program module that contains the methods that are specific to a particular class The class header file must be included in the C program module so that the data structure of this object and the class definition pointer can be accessed Once an object s data structure class and specific functions are defined it needs to be positioned within the class hierarchy The positioning of the class in the class hierarchy is determined by the nature of the class and the methods to be inherited The simpler a class is the higher up in the class hierarchy it is positioned Conversely a more complex class is positioned further down in the class hierarchy The position
86. at colors tiles fonts mouse button bindings and icons can be customized for individual users by modifying the X Window System configuration file Xdefaults This mechanism allows individual users to customize the pres entation of IVIBuild s user interface to suit their own needs e g left handedness black and white display Presentation and Functionality Binding The presentation of the components that make up the user interface of HP IVIBuild i e the buttons menus win dows etc and the functionality the states associated with these components are bound together at run time The func tionality of HP IVIBuild that is the result of pressing a certain sequence of buttons is not dependent on the user interface presentation For example in one user interface presentation drawing a rectangle might be accomplished by selecting buttons labeled P1 and P2 for the lower left and upper right corners of a rectangle and typing the coor dinates into a pop up dialog box In another user interface Attribute Data Build Utility Box Caliback Object Function Zunput Calls Fig 10 Binding HP IVIBuild user interface presentation to functionality at run time OCTOBER 1990 HEWLETT PACKARD JOURNAL 37 Copr 1949 1998 Hewlett Packard Co drawing a rectangle might be a three button sequence in which the user presses the Rectangle button and then clicks on the desired coordinates with the mouse In ei
87. be minimized by in cluding multiple attributes in the Arglist as opposed to having to use one function call per attribute change Attributes can be initialized in the Argiist either statically or dynamically at run time Copr 1949 1998 Hewlett Packard Co Table Categories of API Attributes Category General Coordinate System Trickle Down Color Font Raster Pattern and Line Widget Appearance Callback Description Attributes that are common to most objects For example the object name ZINAME an object s visibility status ZIVISIBLE and user data ZtUSER DATA Theseare attributes that define m Sizeand position suchas an object s height and width ZIHEIGHT and ZtWIDTH m Transformation such as an object s rotation scaling and translation characteristics ZtROTATE ZISCALE ZITRANSLATE m Normalized device coor dinates for placing windows ZtXMIN ZtXMAX ZtYMIN ZtYMAX m Aspect ratio of window device coordinates ZIADJUST ZtXADJUST ZtYADJUST m Aspectratios of serverobjects ZIXPIXELS ZtYPIXELS Attributes that affect the descendants of objects ZVISIBLE ZISENSITIVE Attributes that specify the object s color font or raster m Raster lists Z RASTER LIST m Anobject scolor e g ZIBACK GROUND COLOR ZIFORE GROUND COLOR etc m Anobject sfont ZIFONT m Anobject sraster e g ZtFILL_ RASTER ZtICON_RASTER Attributes that control the appearance of b
88. bles This structure is I created by the API ric tool H static INT32 groupmembership 1 Array containing a state s NULL group membershipinformation k Thepurposeofthisarrayisto help limit state transitions M atcertain times Currently E this feature is not used in kl HP IVIBuild Quam iip Fig 3 Interface areas of HP IViBuild OCTOBER 1930 HEWLETT PACKARD JOURNAL 33 Copr 1949 1998 Hewlett Packard Co static char s rect this state s name All state objects have the following structure static struct DzRect struct ClassDef class Pointer to the dispatch tables char statename Pointertothe state s name INT32 clsindex Aunique id assigned to this state INT8 autoterm This state s autotermination flag if TRUE the state machine terminates the state and if FALSE anaction by the user must terminate the state INT32 selector Message sento the current state locause a transition to this state INT32 group Pointerto this state s group D membership information I Data values assigned to the fields defined above slate rect Initialization y amp DzRect Pointer to dispatch tables objectname Polntertoname 27 State s id number FALSE Stateis NOT autoterminating s_rect Message selector
89. by this display resolution 1 Widget Window Fig 8 Widgets are in their own individual windows and have their coordinates defined relative to these individual windows Graphic objects have their coordinates defined relative to the window object they are located in to get pixel values Since NDCs use the lower left corner of the display as the origin and X uses the upper left corner as the origin the y values of the viewport must be sub tracted from the height of the display for compatibility with the X coordinate system Since this calculation is done at run time the application does not need to know the type of display the application is using Consider a window that occupies the NDC region from 0 0 0 0 to 0 5 0 5 on a display that is 1024 pixels wide and 768 pixels high see Fig 9a When converted to DCs as explained above the window occupies the region of the displayat pixel locations 0 767 to 511 384 see Fig 9b The transformation equations for converting from NDCs to DCs are Pyne Panne X width of display in DCs 1 NDC 1 Pyne Pyunc X height of display in DCs 1 NDC 2 To take into consideration the upper left origin of the X Window System height of display in DCs Pypc 3 P yr Substituting the values from Fig 9a into equations 1 and 3 and compensating for the starting pixel yields 1 0 1 0 0 0 0 5 0 5 0 5 768 Pixels 0 0 0 0 0 5 0 0 Display R
90. ce The sec ond step is to specify the device protocol in a language that HP DIS can compile The third step after successful compilation is to generate the test scripts and test the logic of the developed interface These steps are illustrated by the following example Describing the Interface A block diagram of the system interfaces for this example is shown in Fig 5 The interface between the application and the device interface is an HP UX message queue Read and write subroutines are avail able for the application program developer to send buffers to the device interface and receive buffers from it These subroutines allow referencing either the HP UX message queue name or the device application name The links between the HP UX message queues and the device inter face are established by the run time facility through a con figuration file Fig 6 The configuration file is used by the run time facility to establish the queues start the defined interfaces create the links and configure the ports from the port definitions The configuration process eliminates the need for a detailed understanding of HP UX inter process communication and RS 232 serial port initializa tion The buffers passed through the queues must be designed to carry the information needed by the device interface The device interface can require the application to pass device specific data directly or can translate generic func tions into device specific data D
91. cess is well known to all interface developers and creates a slow re sponse to market needs In the long run the use of communications standards such as the Manufacturing Automation Protocol MAP will eliminate many of the device connectivity problems and the response to market needs will improve significant ly In the meantime many factory floor devices exist and have long useful lives remaining Many are simple devices such as gauges with simple interfaces that may never con form to a standard To reduce the cost of developing customized interfaces for devices that need them and to shorten the time required for such efforts tools are needed to simplify the develop ment and testing of the interfaces This is the objective of the HP Device Interface System HP DIS HP DIS is a toolset that helps developers create and test interfaces between computer applications and RS 232 compatible factory floor devices in less time than before The resulting inter faces run in an HP UX environment on HP 9000 Series 300 or 800 computers HP DIS offers three facilities to make the development and implementation of device interfaces more efficient A development facility provides a high level Protocol Specification Language for defining the communications logic A testing facility provides a test generator a test E FFICIENT DEVELOPMENT OF INTERFACES be 62 HEWLETT PACKARD JOURNAL OCTOBER 1990 exerciser and a device simulator A run t
92. cify global attri butes for the other levels of objects This level includes the window and model objects mentioned earlier Composite Objects These are organizational groupings of primitive objects This includes menus and their com ponent menu panes row columns and scroll lists m Primitive Objects These are basic widgets and graphics objects the basic visual pieces that make up the display Graphics primitives include items such as polylines splines arcs rectangles and circles Widget primitives include pushbuttons toggle buttons text widgets text edit widgets menu buttons and scrollbars Both types of primitive objects can receive input from the user Low Level Objects These are mostly nonvisual objects that are used to specify certain object attributes Objects that handle object data structures and objects that handle events are examples of low level objects Because an object hierarchy is used displays can be created from the top down parent to child or the bottom up child to parent giving the designer a lot of flexibility in implementation Certain objects can be gathered and arranged by making them into children of composite ob continued on page 10 ation inter using the in Fig 2 An appli ce being creati teractive tools provided by HP IVIBuild The tool box utility box and width panels are HP Copr 1949 1998 Hewlett Packard Co Quality Function Depl
93. compiling and testing The compiler not only checks the program syntax but also tests the reachability of all states from to the home IDLE state This check ensures that there are no incomplete paths 66 HEWLETT PACKARD JOURNAL OCTOBER 1990 State Diagram Transition Diagram Computer Device rad Send Message ACK E NAK Retry Exceeded x MSG l TO Time Out a or No Response State Diagram Transition Diagram Computer Device mre Message Time Out msa e o ib Message Reply Message K not OK la Message OK TO Time Out b or No Response Fig 7 Transition and state diagrams for a nontrivial protocol a Message from computer to device b Message from device to computer Time Out Reply Message buc i E Fig 8 Protocol state machine state diagram obtained by combining Figs 7a and 7b 1949 1998 Hewlett Packard Co One of the most powertul features of HP DIS is the matching process It is used for three purposes for determining whether a message matches a request event or a response event for parsing a message into a structure and for delimiting streams of characters from a port Each use is slightly different from the others but they all have the same matching characteristics Through the PSL struct description the user defines the fields in a structure that are to be matched All variables describe a length of data When a struct
94. d replacedid replace the tail object of a point list pointListld with a new point object newpointid E ret ZtReplaceListTail pointListld newpointld amp replacedid Grouping and Reparenting Objects Using the methods and techniques described so far ob jects can be created and grouped together to form an object hierarchy like the one shown in Fig 1 This is accomplished using model objects or composite objects Model objects allow an application to group together composite objects primitive objects and other model objects into one group They are invisible container objects and they do not own any visual attributes Composite objects have visual attri butes and they make it possible to group together primitive widget objects and other composite objects Examples of composite objects include menus menu panes row col umns and scroll lists There are two ways of creating model or composite objects in API creating objects with the child list attribute ZICHILD LIST or assigning a group of objects to another parent objectiid object2id object3id Creating Composites with ZtCHILD_LIST Using ZICHILD_LIST model and composite objects and their descendants can be created either top down or bottom up Top Down The composite object is created with NULL as signed to the child list attribute ZICHILD LIST It then be comes the current composite object and all newly created primitive objects will automat
95. d run was made The solution was said to have converged when the pressure error was 86 HEWLETT PACKARD JOURNAL OCTOBER 1990 less than or equal to that of the first run 0 021 The results of this iterative procedure are given below Typical FIDAP Run Run Numberof Fancfm Pressure PressureDrop Fancfm Iterations Guessed Error Computed Actual 1 5 100 0 021 0 46 in H O 70 2 7 85 0 016 0 40 in H O 90 In this typical example 12 iterations were required to find a value of fan flow rate within 10 of that actually supplied by the fan Given that other simplifications in the model had been made it was felt that this level of con vergence and accuracy was adequate On the CRAY Y MP supercomputer 10 hours of CPU time were required to perform the 12 solution iterations needed Memory needed was 4 0M words of main memory and 87M words of secondary memory or scratch memory For scratch memory a CRAY SSD solid state storage de vice was used This reduced an otherwise substantial O wait time penalty for disc memory devices to a small frac tion of the total run time Numerical Results As mentioned earlier general flow characteristics in cluding the velocity profile and the pressure drop across the system were computed Some typical pictures of the flow velocities through the system are shown in Figs 3 4 and 5 These illustrate well the qualitative features of the flow entering the CPU side and the I O side at the top section turning
96. d the actual results are always shown If the actual results differ from the expected results the trace data output file Fig 14 can be examined to determine the cause The trace data output file contains a detailed description of the data flow through the state table for each case executed by the test exerciser It shows all incoming OCTOBER 1990 HEWLETT PACKARD JOURNAL 67 Copr 1949 1998 Hewlett Packard Co Environment Runime name device Constants Read Write Applic read Applic write Device read Q Device write Increment Start timer Stop timer Calculate Check DLE STX ETX ACK NAK MaxRetry F Maxnumber ot NoResponse I Time outretum status HP ID Device identor Retry exceeded StatusOK Message sent OK retumstatus TimeOutVal F TOvaluo 15 f test 308 f Retry counter Protocol block check character Protocolstatus Protocol destination device Protocol source device F Protocol command F Protocol status Protocol message number Data block Dummy tor DclO Function for BCC check F Timer valve f Bitbucket suci ReplyNak DLENAK struct DataPacket DLE STX dstsrc cmd sts tns data DLE ETX bcc struct RegPacket dstomd data status data I Event Event Type Event definition send message request ReqPacket reply message response DataPacket ACK response ReplyAck timeout
97. d this technique was that some people don t state their feelings directly They might say Forms based applications are good if you have to use a terminal But what they really mean is if given a choice they wouldn t use a terminal at all for that application Once the data was collected it was time for analyzing We formed teams with people from the HP IVI project marketing and several people from outside IAC Some of these people included learning and human factors specialists and a user inter face developer from another division One other person was our QFD consultant Collect Customer Needs and Wants Data Murmurs Analyze Data Categorize Data Based on Features Derived from Murmurs Rank Murmurs into Primary Secondary and Tertiary Groups Create a Tree Diagram of the Features to Ensure that None Are Missing Determine Implementation Methods for Delivering Customer Needs and Wants Determine the Strength of Each Implementation Method in Satistying Customer Needs and Wants Fig 1 The QFD process Customer needs which we called murmurs were categorized nto groups based on some desired customer feature related to issues such as ergonomics or performance When we finished categorizing the murmurs each murmur was ranked into primary secondary and tertiary needs Each of these rankings rep resented a translation of customer needs into quantifiable tech nical terms An example of customer murmurs and
98. dd and delete protocol interfaces dynam ically in a running system A diagram of the HP DIS testing facility is shown in Fig 3 This facility consists of a test generator and a test exer ciser The test generator takes the state table and creates test cases The test cases are fed to the test exerciser which executes each test case by sending messages to the protocol interface under test The test exerciser attempts to achieve each state listed in the state table for up to 100 coverage Optional inputs to the test exerciser are user written test cases The test exerciser executes a sequence of test cases and compares expected results to the results of the protocol interface under test Actual devices or VO ports are not necessary for testing factory floor devices can be simulated by describing their messages The output of the testing facility includes test case documentation and test results The testing facility also provides the following features Full or partial data tracing Either menu driven execution or script execution of test cases Protocol filters to simulate garbled messages time outs and expression matching Notification of percentage covered OCTOBER 1990 HEWLETT PACKARD JOURNAL 63 Copr 1949 1998 Hewlett Packard Co An HP DIS Example There are three steps in developing an interface see Fig 4 The first step is to describe the interaction between the application and the factory floor device interfa
99. ded by HP IVIBuild The functions of these areas are Utility Box This area displays current object information and the menus for object manipulation Tool Box This is the area in which the user selects the objects to be manipulated m Workspace This area displays the windows being created Object Oriented Design in HP IVIBuild HP IVIBuild uses the API functions and the facilities provided by the HP IVI object oriented environment to build its own object oriented system The object oriented concepts of objects polymorphism and inheritance are incorporated into the design of HP IVIBuild Objects In HP IVIBuild objects are very simple data struc tures called states A state is the context of user input i the operation in progress at any particular point in time All states are static bound at compile time and have the same structure Only one field in the structure called a message selector is filled in at run time This field is used to bind HP IVIBuild s user interface presentation to its functionality User interface binding and functionality are discussed later in this article The following is the C lan guage structure of a typical state object This macrois included for compatibiitywiththeHPIVI object oriented environmentand isnotused by HP IVIBuild CLASSVARS ClassVars extern struct ClassDef DzRect Structure containing pointersto this state s method dispatch 7 ta
100. del within another model is called a submodel For example in Fig 1 Model 21 is a submodel of Model 12 The user can create a symbol library out of submodels Cus tomized sets of commonly used symbols can be created saved and reused as submodels Conclusion Based on an object oriented framework the API consists of a simplified yet powerful set of functions for creating and activating user interface components The application developer can learn to use these routines within a short time The developer is also able to combine the dynamic animation capabilities of graphics and the flexibility and interactive capabilities of widgets to enhance user inter faces for process control applications Models of physical objects such as machinery and instrumentation can be created to provide context specific information that the end user can react to more quickly than with a standard terminal oriented interface Copr 1949 1998 Hewlett Packard Co HP IVI Application Program Interface Design To provide the features available in HP IVI the internal design and implementation of the application program interface leveraged concepts and software from graphics packages window technology widgets Xt Intrinsics and object oriented design by Pamela W Munsch Warren 1 Otsuka and Gary D Thomsen NE OF THE MAIN goals of the HP Interactive Vis ual Interface HP IVI project was to leverage fea tures from current user interface and
101. displayed in text format for a clock drawn as a digital clock see Fig 3 The clock object is polymorphic because the same message can be sent to different objects The application does not have to worry about how the time is drawn That is determined when the method to draw the clock interprets the instance data that defines each clock object s internal state A goal of object oriented design is Root Class Class A Parent Class B message classBObj method 2 Fig 4 Inheritance allows methods to be reused Fig 3 Polymorphism allows the same message to be sent to different objects regardless of their internal data types and methods message Object b Display Time 15 00 25 to maximize code generality flexibility and reusability by defining common interfaces that can be supported by many different kinds of objects The mechanism of searching the class hierarchy described above is how the OOE implements the concept of polymorphism Inheritance Inheritance provides the ability to create incremen tal definitions of objects i e one kind of object can be defined incrementally in terms of previously defined objects The new definition extends the existing definitions by adding data to the object representation by adding new methods and by extending the definition of existing methods Using the update time example from above the analog clock object that produces the graphic representation
102. ditional translation factor or flip factor must be added in the y direction to move the origin from the lower left to the upper left corner The NDC height for the window in which the pushbutton in Fig 10 resides is 0 5 NDCs Compensating for the flip factor F results in P y F Pay 0 5 0 25 0 25 NDCs P ay F Pyy 0 5 0 0 0 5 NDCs and 0 0 0 25 Fig 10d shows the result of applying the flip factor The scale factors the translation factors and the flip factor are incorporated into the viewport to window trans formation matrix VTM Combining all the transformation factors in one matrix and performing the transformation operations looks like API Functions Interface to User Code Object Layer Process Attributes and Update Objects Server Object Xt Intrinsics and Widgets X Window System Fig 12 The layers of the API architecture OCTOBER 1990 HEWLETT PACKARD JOURNAL 27 Copr 1949 1998 Hewlett Packard Co Pxxpe 1 Pxwe Pywc 1 SF 0 0 0 SF 0 T T F 1 Fig 10e shows the final transformation of the pushbutton NDCs to X window device coordinates The coordinate points shown in Fig 10e are derived by substituting the values from Fig 10d into transformation equations 1 and 2 and compensating for the starting pixel P xpe 0 0 1024 1 0 0 25 x 768 1 192 Paxpc 0 25 1024 1 1 255 0
103. e Actions List State IDLE Send message Actions Read message from application Build outgoing buffer from incoming buffer Send message to device Clear retry count Increment message number Start timer Event WAIT Read message from device DLE Send acknowledgment ACK todevice IDLE Reply message ACK Stop timer Read message from device Start timer WAIT WAT NAK Stoptimer Read message from device Resend message to device Incrementretry count Start timer WAIT WAIT Replymessage Stop timer Read message from device Check block control character BCC CHECK Time out Stop timer WAIT Send no response message to application WAIT Retryexceeded Stop timer IDLE Send communications error message to application CHECK MessageOK Send acknowledgment IDLE to device Send reply data to application CHECK Messagenot Sendacknowledgment OK device Increment retry count Set timer WAIT The state diagrams of Figs 7a and 7b are combined into one state diagram in Fig 8 The actions to be performed at each state transition are listed in Table I With some additional declarations this table can be transformed into a Protocol Specification Lan guage PSL program that can be compiled Previous deci sions about the form of the messages from the application can be incorporated into the data structures Fig 9 shows the PSL program ready for
104. e LO in the analyzer The conversion loss of such a harmonic mixer exceeds that of the fundamental harmonic mixer shown in Fig 1a but the design effort goes into the preselec tor which is a passive component and therefore somewhat easier to design than a millimeter wave LO Of course once the resonators for such a preselector are available a wideband oscillator may be possible if the active devices can be obtained Block Diagram The method of Fig 1c was chosen for the HP 11974 Series preselected mixers Fig 3 shows the HP 11974 block diagram The RF signal that is to be down converted to IF enters the waveguide flange of the tunable preselector shown in Fig 3 then goes to the isolator and the HP 11970 Series harmonic mixer Electromagnets in the preselector develop a magnetic field which tunes the preselector The scaling electronics transforms the tune ramp voltage of the spectrum analyzer into magnet current The unbiased harmonic mixer was developed previ ously to extend spectrum analysis into the millimeter wave range If used without a preselector the mixer con verts the RF signal to an IF whenever an LO harmonic sweeps past the RF However the horizontal frequency scale is only calibrated for a single harmonic of the LO the 14th for the V band example shown in Fig 4a The desired response the 14 signal in Fig 4a appears as a result as do several unwanted responses resulting for example from the 12th 16th and
105. e System HP DIS is a tool that eases the development of communication links between computers and factory floor devices Inter faces can be developed more quickly than with conven tional code Devices can be simulated and testing is mostly automated Communication links can be scaled using only the routines needed for the application at hand Through the use of this tool factory floor devices from many vendors can be mixed and matched HP DIS can improve productivity reliability develop ment costs and market response and reduce support costs for device interfaces T2 HEWLETT PACKARD JOURNAL OCTOBER 1990 Acknowledgments HP DIS was made possible by the teamwork and dedica tion of many people especially the R amp D team The authors would like to acknowledge the other present team mem bers Frank Leong and Marve Watkins and Ron Becker the project manager who pulled it all together We also would like to acknowledge previous team members Cle men Jue for the development environment David Bruns tein and Tom Hirata for the testing environment and Wes Higaki who was one of the initial investigators Dan Shive and Ron Short of the technical support group made the manuals a reality The authors also acknowledge all the contractors technical writers marketing people and man agers without whom HP DIS could not exist References 1 F Litman Software Tools for Plant Floor Connectivity Auto mation Vol 35 no 4
106. e compensation ap plied Fig 16 shows the frequency tracking errors of the same V band filter with the temperature compensation circuitry enabled The remaining frequency tracking errors fall within a range approximately equal to the 3 dB bandwidth of the filter The preselector peak function of the spectrum analyzer removes these errors at a particular frequency In addition to temperature effects compensation must be provided for the effect of filter tuning delay When the spectrum analyzer sweeps at a fast rate the filter tuned by the current through a coil with inductance of about 0 8 henry tends to lag behind This effect is compensated by placing a differentiator in the HP 11974 tune voltage path Tune Voltage Error Indicator Filter Coil 310 Fig 14 Simplified HP 11974 filter drive circuitry OCTOBER 1990 HEWLETT PACKARD JOURNAL 55 Copr 1949 1998 Hewlett Packard Co 600 u 75 C ES 8 8 Frequency Error MHz e S 8 i 50 60 70 80 Filter Frequency GHz Fig 15 V band filter tr pensation ing error without temperatu At slow sweep rates this circuit has no effect At fast sweep rates additional coil current is provided to help the filter keep up with the spectrum analyzer With this compensa lion applied the spectrum analyzer can be swept at a maximum sweep rate of 40 GHz second Spectrum Analyzer Compatibility The HP 11974 Series preselected mixers
107. e control of these attri butes that the displays created with HP IVI get their dynamic quality One can easily manipulate several attri butes on an object with a single API function call changing location color visibility or some other attribute Other API function calls enable the developer to Create and free objects Manipulate object attributes Save and restore objects Locate objects Obtain user input from primitive objects Perform visual updates of the display Manipulate lists of objects As an example callback objects can be attached to any visual object and cause a callback function to be called whenever a predefined event such as clicking on the mouse button or depressing a key on the keyboard occurs The callback function can be used to obtain and manipulate data from the shop floor and modify attributes of objects 10 HEWLETT PACKARD JOURNAL OCTOBER 1990 on the display e g changing an object s color from green to red or changing the textual information displayed in an object The API functions and the internal design of these functions are described in thearticles on pages 11 and 21 Conclusion HP IVI facilitates the design and implementation of one of the most important parts of any manufacturing applica tion its interface to the user The benefits of the window ing technology of X11 are just beginning to be realized on the manufacturing floor HP IVI is one of the first integrated applications
108. e found in the literature Multivariate statistics has been used extensively by behavioral scientists to analyze latent factors responsible for certain behavior traits Its applications to manufacturing problems based on our literature survey have been very limited 45 67 One method of solving for the ensemble of n variable vectors based on principal component analysis tech niques Briefly principal component analysis describes the variances of the n random variables in terms of a set of mutually orthogonal or statistically independent uncorre lated variables known as principal components Each prin cipal component accounts for a portion of the total variance larger than the succeeding components Statistical ensem bles of then variables can be readily generated from random numbers after the transformation to the principal compo nents because of the statistical independence of the princi pal components The ensemble of n variable vectors is generated in a closed form solution starting from the n variable correla tion matrix R provided that the eigenvalues of R are all positive and the variables are normally distributed For a set of n circuit variables y y having a correlation matrix R it can be shown that the ith statistical variable Copr 1949 1998 Hewlett Packard Co y is given by the expression 24 s a where Xz xa are normally and independently distrib uted random variables
109. e only a small portion of the window For ConfigureNotify events the window object sets the new window placement and size values Then during the next redraw of the window the objects are redrawn to fit within the new window size Coordinate Systems The coordinate system concepts and techniques found in various graphics packages are incorporated into the API functions for drawing graphics objects windows and widgets on the display The user can define the viewing area in world coordinates e g inches feet etc and the API functions transform these coordinates to a window in the X coordinate system pixels A viewport is a rectangular portion of the display onto which window objects defined in world coordinates are mapped Viewports are typically defined in a device inde pendent coordinate system called normalized device coor dinates or NDCs In X a viewport is represented by an X window which is defined in device coordinates DCs The allows users to define the position and size of a window object viewport with NDC coordinates This allows a win dow to be defined as occupying a certain portion of the total display area independent of display resolution Map ping a window object described in NDCs to the device coordinates of a display is straightforward When an appli cation initiates drawing to a specific X server the display resolution of the server is queried The NDC values describ ing the viewport are multiplied
110. e same shadow reversal the pushbutton uses to appear recessed Fig 1 shows the transition from a total 2D appearance to a full 3D appear ance Most people found this 3D appearance appealing It be came a key factor in the subsequent adoption of the HP widgets by the Open Software Foundation OSF for their OSF Motif standard user interface A New Principle The 3D appearance ends up creating a new fundamental graphical user interface principle the visual separation and distinction of what we call user space and interface space User space is where the user s inputs go or where the user performs work Examples are the space provided in a word processor for entering text or the space provided in a paint program for creating images It also includes those areas where the user is asked to input data like the name of a file The rest of the screen is the interface space or the visual manifestations of the applications and or the operating sys tem Included in this category are items like window frames dialog boxes tool panels menus and the metaphor To 005 File Convert Type of Conversion Convert File Name Converted DOS file will be displayed in 1 110 From 005 Fite enter text here To DOS File Type of Conversion p Convert 4 Total 2D ITI Tupe of Conversion Full 3D 40 HEWLETT PACKARD JOURNAL OCTOBER 1990 Converted DOS f
111. e up the user interface can be saved in a file and reused later by other applications using the API functions see Fig 1 HP IVIBuild is itself an HP IVI appli cation program because it uses the API functions described on page 11 as a platform Fig 2 shows the architecture of HPIVIBuild Early in the design of HP IVIBuild we realized that al though the HPIVI application program interface API func tions are several orders of magnitude easier to use than T HE EDITOR BUILDER COMPONENT of the HP In Files Containing Saved User Interfaces Applications Restoring User Interfaces and Adding Functionality Fig 1 HP IVIBuild allows users to create and experiment with different user interfaces and save them in files to be reused by other API applications API application program interface of HP IVI 32 HEWLETT PACKARD JOURNAL OCTOBER 1990 Xlib the X toolkit and widgets they are still very complex to many users Therefore an interactive user interface de sign tool HP IVIBuild was developed to complement the API functions IVIBuild helps promote software development pro ductivity in areas such as rapid prototyping and the design and modification of user interfaces For rapid prototyping HP IVIBuild allows developers to create complex prototype user interfaces The user can interactively place and size all of the primitive graphics and widget objects in a win dow Once the objects are placed
112. ed crystals for quick optimization of charge compo sition and temperature profiles Now that growth condi tions have been optimized a single larger crucible is used for each growth run with a larger charge so that larger crystals can be grown The total volume of liquid charge in thecrucibleat the start of crystal growth is approximately 320 ml The total weight of crystals obtained from the growth is about 70 grams The processing of hexagonal ferrites to spheres is concep tually very similar to YIG sphere processing Because of the brittle nature of hexagonal ferrites proprietary grinding and polishing techniques had to be developed to avoid chipping the sphere poles In addition a separate sphere testing system was developed to test the Q of the hexagonal ferrite spheres which must be tested at the millimeter wave frequencies at which they will be used Summary Because of their high magnetic anisotropy fields spheres made of suitably doped M phase hexagonal ferrites were chosen as resonator elements in magnetically tunable bandpass filters These bandpass filters cover waveguide bands above 26 5 GHz and are used as preselectors in the HP 11974 Series of millimeter preselected RF sections When no outside supplier of hexagonal ferrite spheres could be found crystal growth and sphere processing and test capabilities were developed in house I would like to acknowledge Frank Gary for developing the sphere grinding and polishing pr
113. ed index m ZtMergeListObject to place the list before an object with a known identifier m ZtMergeListTail to place the list at the end of a list In the following example three objects of type ZtLIST OBJ are used to illustrate merging lists Listld references three objects objecttld object2ld object3ld Mergeld references two objects object4ld and objectSld and Newlistid is the list object obtained by merging Listld and Mergeld see Fig 8 Using ZtMergeListIndex to insert all objects of Mergeld into Listld between objectiid and object ld Ztld Listld Mergeld Newlistid int ret val INT32 list index 1 ret val ZiMergeListIndex Listld list index Mergeld amp Newlistld Using ZtMergeListObject to insert all objects of Mergeld into Listld in front of object2id 2119 Listld Mergeld Newlistid object2ld int ret val ret val ZtMergeListObject Listld object2id Mergeld amp Newlistld Indexes pointListid pas a b 18 HEWLETT PACKARD JOURNAL OCTOBER 1990 Removing Lists Objects can be removed from a list by using ZtRemoveListIndex to remove an object at a specified index ZtRemoveListObject to remove an object before an object with a known identifier ZtRemoveListTail to remove an object at the end of a list Children of windows models or composite objects can be deleted by invoking these functions on the list object specified in the ZICHILD
114. efore anything can be displayed at least one of each of these objects must be available Since these objects are required for every appli cation the API will create default high level objects if they are not explicitly created The system object is the highest object in the API object hierarchy This object stores global attributes that affect the input loop the update pass and global resources The input loop is composed of the code that handles user input and an update pass is the process of flushing changes to the display There can only be one system object per appli cation All other objects except low level objects are de scendants of the system object The direct descendant of a system object must be a server object A server object is the interface to the display system Information regarding the display and its physical charac teristics is stored in this object The server object establishes the link between the display device an X11 server and the user application the client Just like the system object there can only be one server object per application Win dows are the only children of the server object Window objects represent the drawable region of the display A window is an area on a display that connects the world coordinate system e g inches mm etc defined for a window to the device coordinates i e pixels of the display system The window can be seen as a viewport into the world coordinate system
115. enough to be a practical CAD tool in product development It is hoped that this approach to design for manufactura bility through synergism of volume production data with design simulation tooling as exemplified by this simulation study will be a significant contribution to manufacturing technology Acknowledgments The author would like to acknowledge Tom Resman the designer of the integrated amplifier for his assistance in this study and in the manuscript preparation References 1 J M Hammersley and D C Handscomb Monte Carlo Methods Fletcher amp Son Ltd 1964 2 D F Morrison Multivariate Statistical Methods McGraw Hill 1976 3 RJ Harris A Primer of Multivariate Statistics Academic Press 1985 4 S Inohira T Shinmi M Nagata T Toyabe and K lida A Statistical Model including Parametric Matching for Analog Inte grated Circuit Simulation IEEE Transactions on Electron De vices Vol ED 32 1985 p 2177 5 O P Van Driel Factor Analysis as an Initial Tool to Obtain Model for Circuit Analysis IEE Colloquium on Model Parame ters for Circuit Analysis 1981 6 C K Chow Projection of Circuit Performance Distributions by Multivariate Statistics IEEE Transactions on Semiconductor Manufacturing Vol 2 no 2 May 1989 pp 80 65 7 A Dileep W R Dutton and W J McCalla Experimental Study of Gummel Poon Model Parameter Correlations for Bipolar Junc tion Transistors IEEE Transact
116. eports 73 Measurement of R L and C Parameters in VLSI Packages by David W Quint Asad Aziz Ravi Kaw and Frank J Perezalonso T Statistical Circuit Simulation of a Wideband Amplifier A Case Study in Design for Manufacturability by Chee K Chow 8 System Level Air Flow Analysis for a Computer System Processing Unit by Vivek Mansingh and Kent P Misegades Departments 4 Inthis Issue 5 What s Ahead 45 Authors The Hewlett Packard Journal is published bimonthly by the Hewlett Packard Company to recognize technical contributions made by Hewlett Packard HP personnel While the information found in this publication is believed to be accurate the Hewlett Packard Company makes no warranties express or implied as to the accuracy or reliability of Such information The Hewlett Packard Company disclaims all warranties of merchantability and fitness for a particular purpose and ali obligations and liabilties for damages including but not limited to indirect special or consequential damages attorney s and expert s fees and court costs arising out of or in connection with this publication The Hewlett Packard Journal is distributed free of charge to HP research design and manufacturing engineering personnel as well as to qualified non HP individuals libraries and educational institutions Please address subscription or change of address requests on printed letterhead or include a business card to the HP address
117. es will deal with this capability We ll also have a research report on aniso tropic dimensional changes in cold drawn copper beryllium alloy as a result of aging OCTOBER 1990 HEWLETT PACKARD JOURNAL 5 Copr 1949 1998 Hewlett Packard Co An Overview of the HP Interactive Visual Interface The HP Interactive Visual Interface HP IVI product uses object oriented and window technologies to provide interactive and programmatic tools for building graphical user interfaces by Roger K Lau and Mark E Thompson interfaces for industrial automation applications is a greater challenge than it has ever been The right details rom a vast array of information must be shown in the appropriate form to the intended group of viewers In ad dition the information that is communicated must be con veyed in such a manner as to enhance the decision making process It often takes more time to develop the interface than it takes to develop any other part of an application HP Interactive Visual Interface HP IVI is designed to help developers provide the type of user interface needed for industrial applications HP IVI is a user interface development tool built on the X Window System Version 11 and runs in the HP UX operating system environment It consists of two main parts an interactive editor HP IVIBuild and an application program interface API Users construct their symbols and displays with HP IVIBuild the builder and write a C
118. esign is important The use of multiple new technologies in a project with few team members having experience in any of these technologies does have its problems and can be a significant factor on the schedule because it is difficult to anticipate problems and avoid pitfalls However using new technologies on a project can be a significant motivator to the engineering staff Benefits and risks of the inclusion of new technology in any product development effort must be weighed carefully Chuck Robinson Section Manager Industrial Applications Center Robin Ching Project Manager Industrial Applications Center OCTOBER 1990 HEWLETT PACKARD JOURNAL 7 Copr 1949 1998 Hewlett Packard Co er of HP IVI It is an API application because it uses t HP IVI API library of C functions to handle both the visual and the nonvisual aspects of creating objects such as man aging object data structures and performing operations re quired to manipulate objects Consequently the windows and models created and saved by the builder can be restored by an API program and vice versa see Fig 1 For the most productive use of HP IVI the user first creates the windows needed by an application using HP IVIBuild and then mobilizes the created windows using a C program contain ing API functions Fig 2 shows an application user inter face being created with HP IVIBuild Although an entire HP IVI application could be written using just the API C f
119. esign the HP 11974 Series by adding tunable bandpass filters as preselectors to the HP 11970 Series unpreselected harmonic mixers we looked for the easiest way of doing things to make the best use of our resources At the outset we had decided to use doped hexagonal ferrite spheres as filter resonator elements Their built in frequency offset see article page 59 allowed us to employ existing YIG tuning magnet designs to cover waveguide bandwidths Because the HP 11970 mixers have TE waveguide inputs and because it seemed extremely difficult to reduce typical YIG filter loop coupling struc tures Fig 5 to the small sizes that would be required to make filters for the highest frequency band 50 to 75 GHz we decided to use waveguide as the transmission medium in our filter The high frequency 53 to 80 GHz barium ferrite filter work done by Lemke and Hoppe served as a starting point for our filter design Their two sphere iris coupled filter used crossed input and output waveguides Fig 6 and produced RF magnetic fields in the two waveguides that were perpendicular to each other at the iris to reduce out of band leakage A linear taper was used to reduce the height of the waveguide to allow a smaller gap between the magnet pole tips A two sphere filter was built in U band 40 to 60 GHz to demonstrate the feasibility of the crossed waveguide filter approach This filter had typical insertion loss of 4 5 dB a 3 dB bandwidth
120. esolution 1024 Pixels 0 767 511 767 1023 767 Fig 9 a Window defined in normalized device coordinates b The same window defined in device coordinates OCs in the X Window System OCTOBER 1990 HEWLETT PACKARD JOURNAL 25 Copr 1949 1998 Hewlett Packard Co Payne 0 0 x 1024 1 0 Piypc 768 0 5 768 1 384 0 5 1024 1 1 511 sync 768 0 0 768 1 1 767 These coordinate values are shown in Fig 9b To define what is drawn within the window object the user defines what portion of the world coordinate WC Display id 0 5 1 0 Viewport tor Window Defined in NDCs 05 05 a Window Window 0 05 0 318 0 3 0 318 0 0 0 25 NDC Origin 0 05 0 067 0 3 0 067 b e 0 0 0 0 0 25 0 25 0 25 0 0 0 383 space is viewable in that area This viewable area can be changed at run time to perform operations such as panning or zooming To draw to the X window representing the user s window object the API must convert all values in WGs into the device coordinates of the display WCs are transformed to pixels in a two step process The first step transforms the WCs to NDCs and the second step transforms the NDCs to DCs Viewable Area in WCs 10 0 85 0 110 0 85 0 m 1 0 1 0 10 0 47 5 60 0 47 5 1 0 0 5 10 0 10 0 60 0 10 0 110 0 10 0 J Wi
121. essed By adjusting the spheres farther apart or closer together and by changing the iris diameter and the sphere size the best compromise between filter insertion loss image rejection and off resonance isolation can be achieved Two sphere filters were built in the other millimeter wave bands using the information obtained from the U band filter and applying appropriate scaling factors The results for insertion loss and off resonance isolation for the family of two sphere waveguide filters are shown in Figs 8 and 9 respectively The 3 dB bandwidths of these filters were 200 to 350 MHz Although the insertion loss results were acceptable the image rejection and off resonance iso lation of these filters were not sufficient for instrument applications The goal was then changed to design a filter with off resonance isolation and image rejection greater than 55 dB A literature search showed three sphere and four sphere 50 Frequency GHz Fig 7 Two sphere U band filter response Copr 1949 1998 Hewlett Packard Co U Band 5 3 vBang Band z 5 3 A 7 H a ot tet ieee Tec aS LL 0 10 20 30 40 50 60 70 80 90 100 of Band Fig 8 Insertion loss of two sphere filters waveguide filter designs but none of them would give the required off resonance isolation at millimeter wave fre quencies Our next design consisted of two of the above two sphere filters under one set of
122. essions and 3 a state table consisting of current state ID event ID action list and next state ID tuples In the state table the action list specifies HP DIS action routines or user action routines Action routines operate on the variables in the identifier table HP DIS provides a header file DcTypes h which can be used by user action routines written in the C pro gramming language to simplify parameter passing The HP DIS supplied action routines are listed below DcButMod Buffer modification DcCksum Checksumming DcClock Timer DcOntr Counter DeConvert Data conversion DcDelay Delay DcEncode Data encoding DcExit Terminating the protocol interface DcFlag Flag setting Deio Input output DeLogAd_AB Address builder OcMove Move DcScan Data scanning DcTabinit Table initialization DcTabScan Table scanning DcBulMod Buffer modification An The HP DIS action routine DcClock activates or deactivates a time counting facility Timer counters are caller supplied HP DIS variables The HP UX system interval timer ITIMER REAL is used to update the time counters in real time A SIGALRM signal is delivered when the system interval timer ITIMER REAL expires and all active timer counters are updated Updating a time counter can trigger an event if the timer counter exceeds a specified time out value In the following example the event Time Out is triggered when time counter is greater than 60000 60 sec onds Variables long time c
123. ett Packard Company HEWLETT PACKARD JOURNAL scribe change your address or delele your name from cur mailing fist send your request to Hewlett Packard 3200 Avorue Palo Alto CA 94304 U S Include your cid address label f any Allow 60 days CHANGE OF ADDRESS 5953 8583 Copr 1949 1998 Hewlett Packard Co
124. evice interfaces can range from very device dependent to completely device indepen dent In the latter case more logic will be required in the device interface Factor Floor Device Interface Write Read Process Factory Floor Device Fig 5 System interfaces for HP DIS example The queues are HP UX message queues 64 HEWLETT PACKARD JOURNAL OCTOBER 1990 For the sake of simplicity this example uses the device dependent approach The application outbound buffer con tains a six byte header and a variable length data string The application inbound buffer contains a status byte and a variable length data string Specifying the Protocol One of the methods of specifying the protocol is a transition diagram translated into a state diagram This is particularly convenient for translating the protocol into a language HP DIS can compile Figs 7a and 7b describe a transition diagram and a state diagram for a nontrivial protocol This example protocol is based on the Allen Bradley Data Highway I protocol but only exempli fies the major features This example assumes synchronous communication No new request is sent from the computer to the factory floor device until a previous request is satis fied The computer sends a message MSG to the device Fig 7a and waits for an acknowledgment from the device ACK The computer then waits for a reply message Fig 7b Each message consists of block control characters a header and
125. experts In this case we had two groups of experts We found that it was important to have a main conduit or interpreter between igner and the rest of the software the user interface de team Without someone to answer all of the questions the Copr 1949 1998 Hewlett Packard Co user interface designer asks and interpret the various dialogs with the team members the communication pro cess really breaks down One designer interfacing with a half dozen individual team members means a half dozen different interfacing styles Another lesson we learned is how important it can be to have an early vision of what you are trying to do Tools exist that enable designers to create this vision and user scenarios quite quickly The power and usefulness of these visuals should not be underestimated They are powerful catalysts for people s thinking and communication Once these are analyzed discussed and modified the product is better understood by all concerned Only at this point should the interface coding begin The mistake should not be made of bringing the visual design help in at the very end to fix up the icons Chances are the flaws go far beyond cosmetic graphics and at this point the investment has been so great that significant changes are nearly impossible Acknowledgments Acknowledgments are due some of the key people who are responsible for this successful collaboration First to Steve Joseph and Chuck House o
126. explicit or de facto To these ends the basic framework of HP IVI is based on software that was purchased as well as software that was produced by other entities in Hewlett Packard The HP IVI project team realized the benefits that could be obtained by leverage early on The basic object oriented framework the error handling routines the X11 client library and server the X toolkit and the HP X widget set were all the work of others While we certainly achieved our goals of reducing design implementation and support costs we missed our orig inal time to market goals Following are some of the lessons we learned about leveraging existing software The quality and stability of existing code is a critical factor If there are many defects in this code much time will be spent isolating the problem and negotiating with the software supplier to have it repaired This can wreak havoc with a project schedule One way around this is to obtain the source code for the underlying software and make the repairs locally This may provide the most timely solution but also raises many supportability questions Negotiating enhancements to the existing software may be difficult Priority lists may not mesh well between vendor and receiver Important enhancements in the underlying software may be delayed because of this Performance of a product may be adversely impacted by exist ing software If this is the case lobbying for improvements may be
127. ext activation The Substate Once current a state controls its own actions using a local variable called the substate During a sequence of operations the messages start backup hit and undo may be sent repeatedly to the current state These actions do not cause interstate transitions Rather they cause intrastate transitions The current state does not change but the mean ing of the next input event may have to be interpreted differently dependingon the sequence of messages the state has received since it was made current The value of the substate is changed to reflect the context of the next hit backup or undo Note that start is always sent after every action whether the action causes an intrastate or interstate transition This is part of the protocol established for a state by the state machine Uniformity Great care was taken to ensure that the same actions have uniform behavior no matter which state is current The HP IVIBuild team developed guidelines for developing states and intrastate transition diagrams were developed before the development of a particular state so that the uniformity of actions could be assessed by the whole team The result is a tool with very modular units of functionality that all behave in a consistent and intuitive manner The HP IVIBuild User Interface HP IVIBuild s user interface was designed as a collabora tive effort between the HP IVIBuild team members and the industrial design department
128. f SESD for letting us work 3D effect ing the two color Fig 6 Ac outside of our own division Both of them have been amaz ingly farsighted in encouraging us to work wherever we can use our expertise to help HP product development At HP s Industrial Applications Center IAC where HP IVI was developed thanks go to section manager Chuck Robin son project manager Vicki Mosely and team members Steve Witten Pam Munsch Scott Anderson and Ron Mac donald for their patience and openess And within IAC mrketing special thanks to Dushyant Sukhija and Andy Lerner for their enthusiastic adoption of visual selling tech niques Finally a special acknowledgment to the other members of the industrial des team Barry Mathis and Shiz Kobara References 1 Deininger and Fernandez Making Computer Be havior Consistent The HP OSF Motif Graphical User Interface tt Packard Journal Vol 41 no 3 June 1990 pp 6 12 Minds and B J Ellsworth Programming with HP OSF 2 D Motif W M R a New Ge 4 OSF Motif pp 26 35 The HP Softbench Environment An Architecture eration of Software Tools Ibid pp 36 47 Ibid p 8 Copr 1949 1998 Hewlett Packard Co Authors October 1990 up IM Roger Lau a technical mar keting engineer at HP s In dustrial Applications Center provided technical support for HP IVI Roger joined HP s Data
129. f one central callback list The API method of handling Scan for Input File Descriptors select Call User Time Out Callback Events Pending Input User Call User File File Descriptor Descriptor Callback Fig 4 The API input loop callbacks eliminates having one attribute per callback for each object type and eliminates having to add and delete attributes when reasons change Time outs and file de scriptor callbacks are attached to the API system object which stores global attributes and resources X event callbacks are registered on the window objects The API creates an identifier Ztld for each object that an application creates However the data returned to callbacks from a widget consists of a widget identifier and widget specific data which is unusable to API applica tions This problem is solved by minifunctions that are registered with the widgets These minifunctions are inter faces that convert widget specific data into something that can be understood and used by the API When a minifunc tion is attached to a widget the object identifier Ztld is also attached to the widget This scheme allows widgets to be treated like other API objects when widget input is re ceived Get Next X Event Xthexit vent Expose on Window Move and Resize Window ConfigureNotity on Window Redirect Event to Window Dispatch Event to Xt intrinsic XtDispatchinput
130. f software components objects Also once a stable and reliable library of objects is avail able software development and maintenance costs should be reduced In the API a special utility was used to create an object oriented environment from C language programs The box on page 29 describes some basic object oriented concepts and an overview of the API object oriented envi ronment The special utility used for creating the object oriented environment is described later in this article Input Handling The input handling model for the API is based on X Xt Intrinsics and widgets The Xt Intrinsics provide a way to call application functions when certain events occur These functions are called callbacks and are attached to widgets The Xt Intrinsics provide input handling capabilities for X events time outs and file descriptor input through the XtMainLoop function This function consists of an infinite loop calling XtNextEvent to get the next event and XtDis patchEvent to send the event to the appropriate processing function see Fig 3 Because the API provides several spe Fig 2 The coordinate systems and the transformations involved in transforming an object from world coordinates to device coor dinates Device Coordinate DC System Pixels 1023 767 Copr 1949 1998 Hewlett Packard Co cial input features the project team implemented its own version of XtMainLoop The basic API input loo
131. frame microwave spectrum analyzers HP 8563A HP 8566B HP 70000 Copr 1949 1998 Hewlett Packard Co 11974V CALIBRATION SN 3001400104 17 Apr 1990 n T n 14 1 21 4 MHz _ LO Power 16d8m tort T 29 B BN T EN S l ars 1 FT I I T TANIE CONV I I T 55 ANA qp LU Ly I RIS Y 404 7 i L1 t L o 55 60 65 70 75 FREQUENCY GHz FREG CONV LOSS FREG CONV LOSS FREG CONV LOSS Fig 18 Conversion loss calibration chart is supplied with each RF section The data is entered into the mainframe spectrum analyzer OCTOBER 1990 HEWLETT PACKARD JOURNAL 57 Copr 1949 1998 Hewlett Packard Co A band and 450 MHz in V band Conversion loss data for each instrument is required to make accurate amplitude measurements Each HP 11974 is shipped with a graph and a tabular listing of its conver sion loss as a function of frequency as shown in Fig 18 The conversion loss measurements are traceable to the United States National Institute of Standards and Technol ogy Data from the conversion loss table can be entered into the spectrum analyzer so that amplitude readings will automatically be referenced to the input of the HP 11974 In addition to the conversion loss table and graph a conver sion loss label is permanentl
132. function provides a small offset to the tune voltage to peak the filter on the signal being measured Because of the internal anisotropic field of the barium ferrite spheres very little current is required to tune the filters to the lowest frequency of the band For all four bands from 26 5 GHz to 75 GHz the coil current required at the lowest frequency is approximately 70 milliamperes The filters then tune to higher frequencies at a rate of 60 to 70 GHz ampere As a result the widest frequency bands require the most current The A band with a span of 13 5 Magnet InputOutput Waveguide iris Plate Barium Ferrite Resonator Spheres Kapton Sheet Transverse Waveguide f LAS Magnetic Center Magnet Fig 13 Four sphere filter assembly Copr 1949 1998 Hewlett Packard Co GHz typically requires 270 milliamperes of coil current to tune to 40 GHz V band with a span of 25 GHz typically requires 425 milliamperes of coil current to tune to 75 GHz Coil current is provided by a 50 volt power supply The coil current flows through the filter coil a transistor that controls the amount of current flow and a 3 10 resistor that is used to monitor the current flow as shown in Fig 14 To minimize the temperature dependent tracking er rors the 3 10 resistor has a low temperature coefficient 5 ppm C as do resistors in other critical locations The power supply was chosen to be 50 volts to accommodate
133. gets or OSF Motif widgets are particularly well suited to this type of interface because the physical reality they convey is much closer to the mental model most people have of activities that are control panel oriented Fig 2 shows one window for an office oriented application and another for an instrument control panel HP IVIBuild before Redesign In the early stages of development the HP IVI team used the initial version of the widget code from HP s Information Technology Operation The early results of their using this code produced the 3D appearance shown in Fig 3 Unfor tunately the 3D effect was largely lost and the user interface was hard to understand This early result was not a surprise because the HP IVIBuild team had not yet had enough experience with widgets and consequently had little notion of how to achieve and use the 3D effect They were also unfamiliar with many of the standard techniques and prac tices for creating graphical user interfaces Our group had concurrently been using the 3D widgets with our own HP SoftBench tools That successful experi ence plus the acceptance of HP widgets for OSF Motif gave us a certain amount of credibility As a result we soon found ourselves in contact with the HP IVIBuild team Like our experiences with the ITO team in the development of widgets the HP IVIBuild people were very open minded in letting us get involved with their product HP IVIBuild was different for us in that it n
134. gineering Systems Division SESD We are former industrial designers who switched our design focus from designing hardware enclo sures to the area of user interfaces plus one graphic design er At the time our division was developing what would become the HP SoftBench environment and we were also looking to ITO for the necessary widgets Rather than pas sively waiting to see what they might provide we were encouraged by our management to lend our professional expertise to the widget development and ITO was open minded enough to listen to some of our ideas We didn t begin with any proven graphic user interface expertise We had done some design analyses of the leading graphical user interfaces Also coming from a background in which our experience and training forces us to process information visually gave us some ideas about how an ef fective graphical interface should look And because our experience with software and computers was limited to being application users we had some first hand knowledge about the user interface requirements for users who are not software literate Basic Principles Three principles have established the foundation for graphical user interfaces in recent years notably in office oriented applications The first principle is that it is easier for most people to have their alternatives presented to them in a manner that allows them to make choices rather than having to remember all of the alternatives Choo
135. h the effective source impedance of the generator and the oscilloscope in parallel R R so the input current is determined solely by the test equipment connected to the circuit Thus current I t Vyen t Ryeny since the package under test is virtually a short circuit Virtually all of the current from the ramp generator flows through the package trace so the voltage is determined solely by the trace inductance and resistance Again if the rise time of V n is much greater than the time constant of the generator and package induc tance the voltage across the package quickly becomes Vout L di dt R L The output pulse consists of the sum of two components 1 a flat topped pulse like the one in the capacitance measurement and 2 a ramp proportional to the input current If we separate the two voltages in Fig 4 call the inductive voltage V represented by the plateau voltage and call the resistive voltage V the final voltages after the ramp can be found from L R VixRgon Vgonmax 3 VR dV dt 2 where dV dt is the slope of the ramp voltage and is the final voltage of the V step see Fig 4 The bounce caused by the partial inductance of the PGA ground net can be canceled by driving a third uncoupled signal trace grounded to the shield at the inner lead bond with a negative going ramp of the same magnitude The third lead must be uncoupled so that mutual inductance does not c
136. he results were as follows 76 HEWLETT PACKARD JOURNAL OCTOBER 1990 Parameter Measured Calculated Difference Self Lof Vpp 97pH 79pH 19 SelfLof Vp group1 0 88nH 0 77nH 14 Self L of V group 2 118nH 1 06nH 1196 Self Cof Vpp 4 96nF 4 92nF 196 SelfCofVp group1 0 66nF 0 62nF 696 SelfCofVp group2 0 5 nF 047nF 696 Note Vpp is the logic power supply voltage and is the driver supply voltage Measurement Errors In the Vpp inductance measurements the topology forced us to put all eight ground wirebonds on the same side of the Vp wirebonds instead of four on each side as the chips are actually bonded Moving all the ground wirebonds to one side of the Vpp wirebonds may increase the inductance of the wirebonds by up to 50 This effect accounts for most of the difference between the calculated and measured values of the Vpp inductance Fig 5 compares the measure ment bonding pattern and the pattern the package was designed to use in actual operation Another source of error is the shape loop height length etc of the wirebonds The wirebond shape may be turn out to be different from the one that was analyzed 4 GND g power 4 GND Chip Package 4 GND 3 4 GND S a Chip L Package b Fig 5 To measure Voo inductance it was necessary to put all eight GND wirebonds on
137. he three authors the other members of the API development team were Scott Anderson Hai Wen Bienz Mark Thompson and Mydung Tran References 1 F E Hall and J B Byers X A Window System Standard for Distributed Computing Environments Hewlett Packard Journal October 1988 Vol 39 no 5 pp 46 50 2 K H Bronstein D J Sweetser and W R Yoder System Design for Compatibility of a High Performance Graphics Library and the X Window System Hewlett Packard Journal December 1989 Vol 40 no 6 pp 6 12 3 Ibid p 7 4 J A Dysart The NewWave Object Management Facility Hewlett Packard Journal Vol 40 no 4 August 1989 pp 17 23 5 T F Kraemer Product Development Using Object Oriented Software Technology Hewlett Packard Journal Vol 40 no 4 August 1989 pp 87 100 OCTOBER 1990 HEWLETT PACKARD JOURNAL 31 Copr 1949 1998 Hewlett Packard Co HP IVIBuild Interactive User Interface Builder for HP IVI Using the facilities provided by HP IVI s application program interface HP IVIBuild allows developers to create and experiment with different types of application user interfaces save them in files and bind them to the functionality of the application at run time by Steven P Witten and Hai Wen L Bienz teractive Visual Interface product is HP IVIBuild As its name implies HP IVIBuild is a tool that is used to build user interfaces interactively The windows and objects that mak
138. he window object removes all Expose events for this window from the queue and keeps two lists of corresponding extent objects Remember that an extent object consists of two point objects that define a rectangular Graphic Object a Circle Window a Method for Drawing Circle Extent Object Graphic Object Point Objects m Fig 7 An API graphic object with an extent for defining the smallest rectangle around a graphic object a The graphic object a circle in a window and the extent represented by P and P b internal representation of the graphic object Copr 1949 1998 Hewlett Packard Co region One list contains the extents of each Expose event in device coordinates This list is used in the server object to create X clip rectangles when graphics objects in the exposed region are redrawn The second list contains ex tents of each expose event in normalized device coordi nates After constructing these two lists the window object goes through a redraw pass of the objects in the window When the graphics objects are told to display themselves they check the previous normalized device coordinate clip list to see if they are in the exposed areas If they are they send a message to the server object to do the X drawing commands This scheme ensures that only those objects that are actually exposed get redrawn by the server object and it significantly improves performance if exposed ob jects ar
139. higher harmonics In the spectrum shown in Fig 4a the RF input consists of several signals from the frequency comb of a multiplier with outputs every 5 1 GHz The unpreselected harmonic mixer shows several unwanted responses to each comb Display Fig 2 Microwave spectrum ana lyzer block diagram showing inter face points A B C D with the millimeter wave RF sections shown in Fig 1 Copr 1949 1998 Hewlett Packard Co BaFe Tuned Preselection Filter isolator IF Output 310 or 321 MHz RF in A 1 a Fig 4 a Anunpreselected spec 50 to nput signal consist ng of comb lines from a multiplier There are several unwanted re oonses to each comb line The harmonic responses to the 51 trum analyzer sweep from GHz comb line are labeled b A preselected spectrum analyzer weep for th e same input signal The multiple responses are elimi nated and the multiplier comb lines every 5 1 GHz are clearly b displayed OCTOBER 1990 HEWLETT PACKARD JOURNAL 51 Copr 1949 1998 Hewlett Packard Co line thereby producing many responses most of which are unwanted and severely hamper measurements The HP 11974 preselected mixers add a waveguide track ing preselectorto the harmonic mixer The resulting V band display is shown in Fig 4b Here only one response occurs for each of the five comb lines Hexagonal Ferrite Filter Design Having decided to d
140. iar with window systems Therefore we had to develop a process to disseminate technical information and promote technical expertise among the project team very quickly This was accomplished through training the exchange of information during design and code reviews and the simple sharing of expertise among the project team The following observations come from our experience with object oriented programming and design Careful consideration should be given to mapping object classes to source code files The consequences can be fre quent file access conflicts when changes are made to a file The temptation to redo class hierarchies should be controlled Developers must be careful to make practical choices on when the class hierarchies are sufficient First time users should not expect magic We believe that there was a significant learning curve involved in our decision to use object oriented programming and design 9 Once the learning curve is overcome the object paradigm Is natural and productive one to use for developing software products Object oriented programming and design have a technical jargon that might mystify developers and their managers at first Therefore familiarity with and consistent use of terminol must be established at the start of the project The object paradigm is not applicable to all software engineer ing projects Knowing when to reject this technology in favor of a procedure based d
141. ically become the compos ite s children For example to create a menu system from the top to the bottom start from the top of the menu hierar chy and work down creating children This process is sum marized in the following steps Create the menu object ZIMENU with the ZtCHILD LIST attribute set to NULL This will make the menu the current composite object Create a menu pane object ZIMENUPANE OBJ This will make the menu pane a child of the menu object and also make it the current composite object Create the menu button objects This will make the menu buttons children of the menu pane 9 Change the attribute ZICURRENT COMPOSITE on the sys tem object ZtSYSTEM OBJ to the menu object created in the first step This will make the menu the parent of the next menu pane Repeat the last three steps until all the menu panes and menu buttons are created Bottom Up To create a composite object from the bottom up create all primitive objects put them in a list and then create the composite object setting the ZICHILD LIST attribute to the Ztld of the object list For example to create a menu system from the bottom up start from the bottom of the menu object hierarchy making the newly created objects children of objects higher in the menu hierarchy This pro cess is summarized in the following steps 9 Create a group of menu buttons and put them in a list object ZILIST OBJ 7 Create a menu pane with the ZICHILD LI
142. ified by the user in the function Arglist If the file exists the user also has the option to overwrite the existing file Objects or defaults of one appli cation can be retrieved easily in another application with the ZtRestore call In the following example the window windowld is saved into a file named windfile w int return_val Ztld windowld filename arglist static ZtArgListltem saveArglist ZIFILENAME ZiValueType windfile w ZIOVERWRITE ZtValueType TRUE NULL ZiValueType NULL return val ZtSave windowld saveArglist Locate Objects The capability of locating the closest object near a user defined point in a window is provided by the function ZtFindByLocation Users can control the aperture of the search i e how close or how far from the point and the depth of the search i e whether or not the action should be recursively applied down to primitive objects within any model or composite object For example a row column object contains a pushbutton object a text object and a scrollbar object A mouse click i e a button event gener ated on the pushbutton will cause ZtFindByLocation to return the 219 of the pushbutton if the function Arglist contains the value TRUE for the ZtIRECURSIVE attribute If ZIRECURSIVE is set to FALSE the return value of ZtFindByLocation will be the 219 of the row column object instead of the pushbutton see Fig 5 ZtFindByAttribute also enables the user to ma
143. ile will be displayed In Al Flie Name N From 005 Fite Displayed Directory C WINDOWS Fig 1 Transition from total 2D ap pearance toa full 3D appearance Copr 1949 1998 Hewlett Packard Co ical desktop The interface space whether controlled by the application or the operating system is where all of the 3D effect is found In office oriented applications which have been driving the graphical user interface movement to date the 2D user space is usually dominant in terms of screen area The main focus of these applications is generally to provide a tool that allows the user to create different forms of docu ments such as mail messages memos charts spreadsheets overhead slides and newsletters Based on these applica tions the user space is perceived to be the WYSIWYG equivalent of some sort of paper document whether a small notepad or a large drawing It is predominantly two dimen sional which is appropriate because the resulting docu ments are also two dimensional There is an emergence of graphical user interfaces in which the interface space dominates because the main function of the applications is not document creation but some form of process setup and control Examples include things like configuring and running a set of test instru ments or monitoring and controlling a complex tempera ture control system or an assembly line HP IVIBuild is geared to create interfaces of this latter type The 3D wid
144. ime facility exe cutes the protocol in real time Fig 1 shows a typical pro tocol development cycle and the use of the HP DIS toolset HP DIS the Tools Approach A diagram of the HP DIS system is shown in Fig 2 The three bubbles correspond to the above mentioned three facilities provided by HP DIS These allow the system de veloper to develop test and run device interfaces The development facility is simply a compiler that gen erates a protocol interface The protocol interface is an executable process that forms the central component of an Standard Process Corresponding Steps Using HP DIS Understand application needs Understand device communication protocol and message formats Design protocol interface architecture functionality and modularity Write application calls to protocol interface Create protocol interface rotocol Specification Create tests using the HP DIS test facility Execute tests using the HP DIS test facility Define the configuration and execute the protocol interface modules 11 Fig 1 The process of creating a device interface Copr 1949 1998 Hewlett Packard Co User Written Codi Action pst Routines Test Cases Executable Protocol Interfaces and State Tables 0 2 223 Test Contiguration Results Test Case Documentation Fig 2 HP DIS facilities HP DIS system The input to the compiler is a description of the device protocol written in Protoco
145. ing of a class within the class hierarchy is defined within the library definition file This file defines the methods that are avail able for messaging to a class and the methods that can be inherited by that class Adding an API Object Adding a new class to the API class hierarchy is a four step process This process is illustrated for the circle class in Fig 13 First the library definition file graphic r is used as the input to the rtc tool The rtc tool takes the library definition file and produces several files as output One of these output files circie ric in Fig 13 is the run time class information file or file A file is created for every class defined in the library definition file It contains the class definition structure and the method dispatch tables for that specific class The file is included at the end of the class definition file for that class when the class definition file is compiled step 2 In the third step the new library definition files graphic h and graphic c are com piled Finally the pointer to the new class must be added to the file that defines the class hierarchy This file is called the glue file classlibs c In step four classlibs c is compiled with the class header file graphic h to produce the object file classiibs o When these object files circle o graphic o and classiibs o are linked into an application the addresses to the methods supported by the various cl
146. inimum of two arguments the receiver of the message i e the object and the message selec tor The message selector consists of a category name and a method name The object receiving the message looks up the category selector in the category table and then looks up the method in the corresponding method table This selection mech anism is controlled by a set of central messaging routines These routines are contained in the message interface to the OOE Every object contributes a dispatch table that the messaging routines search to determine which object implements a function fora particular selector Associated with each selector is a pointer to a method that is called to implement the response to the message see Fig 2 This connection of a message selector to the appropriate method is called binding Binding can take place at compile time early or static binding or at run time late or dynamic binding The OOE currently implements static binding In the OOE the message selector is the key to determining which function gels called when a message is sent to a particular object The message selector is a 32 bit quantity consisting of Method Tables Table a Ipper 16 Bits Lower 16 Bits message Object selector Receiver Fig 2 Connecting a message to a method in an object OCTOBER 1990 HEWLETT PACKARD JOURNAL 29 Copr 1949 1998 Hewlett Packard Co E two 16 bit fields The upper 16
147. ions on Solid State Circuits Vol SC 12 1977 p 552 OCTOBER 1990 HEWLETT PACKARD JOURNAL B1 Copr 1949 1998 Hewlett Packard Co System Level Air Flow Analysis for a Computer System Processing Unit Numerical simulation of particle traces using finite element modeling and supercomputers gives a good qualitative picture of air flow features Computed velocity profiles and pressure drops have reasonably good accuracy by Vivek Mansingh and Kent P Misegades TEADY VISCOUS THREE DIMENSIONAL AIR S FLOW within a computer system processing unit has been analyzed using finite element modeling The objective of the study was to investigate the effective ness of finite element modeling in predicting the air flow characteristics within a computer A full scale three dimen sional finite element model of an HP 9000 Model 850 com puter was created using FIDAP the finite element code from Fluid Dynamics International This model consisted of over 60 000 nodes and over 40 000 8 node brick ele ments Extensive computations were carried out using CRAY Y MP supercomputers General flow characteristics including velocity profiles and pressure drop across the system were computed Numerically calculated particle traces were recorded using video equipment It was found that numerical simulation of particle traces can show good qualitative features of the flow through the system and the modeling results of velocity profiles thro
148. is based on principal component analysis a branch of multivariate statistics Examples are presented showing the application of this technique to a custom wideband bipolar amplifier IC used in the HP 54503A digitizing oscilloscope The tech nique was used to set an accurate specification early in the design stage and to identify a process problem affecting the circuit performance INTEGRATED CIRCUIT DESIGN there is a need for 78 HEWLETT PACKARD JOURNAL OCTOBER 1990 Principal Component Analysis Consider an integrated circuit having n parameters such as resistor values and transistor gains These parameters vary statistically from lot to lot from wafer to wafer and from die to die because of the time and spatial variations of the fabrication process The manufacturing distributions for this IC can be simulated if an ensemble of n variable vectors can be generated having the same statistical vari ation as the circuit parameters The accuracy of these simu lations depends to a large extent on how accurately the intercorrelations of the n variables are accounted for The n variable vectors can be generated by multivariate statistical techniques 3 starting from the correlation ma trix of the n variables Multivariate statistics analyzes the structure of complex statistical variables to identify latent factors factor analysis or the principal components prin cipal component analysis A comprehensive treatment of this subject can b
149. ital oscil loscopes and pulse generators Good correlation between the calculated and measured results for the PGA package was obtained This measure ment technique has also been used to measure parameters of TAB tape automated bonding packages printed circuit PGAs and printed circuit board connectors with good re sults and could also be useful in other electrical model verification experiments We would like to thank Ken Lee and Ralph Liu who assisted with this effort and provided invaluable ideas and advice We would also like to thank Bob Crawford and Ron Bernard for designing the probes and writing the software for the measurements and Pauline Prather for her support and expertise in bonding and assembling the test devices Colorado IC Division assembly particularly Dave Gilzean helped wholeheartedly to make this effort possible References 1 Stripcal is a program developed by Dave Quint Hewlett Pack ard Colorado Integrated Circuits Division It uses transmission line analytical equations to calculate R L and C values 2 Ind3 is a program developed by Ken Lee Hewlett Packard Cir cuit Technology Group It uses the method described in A E Ruehli Inductance Calculations in a Complex Integrated Circuit Environment IBM Journal of Research and Development Sep tember 1972 pp 470 481 3 D W Quint G L Brown and R Kaw Measurement of R L and C Parameters in VLSI Packages Proceedings of the 1988 Design Techn
150. l Specification Language PSL PSL allows the user to describe a state graph and its associated state table in a high level format see Finite State Machine page 65 Other inputs to the development facility are subroutines that can be linked to the protocol interface In HP DIS these are called action routines see Action Routines page 69 The run time facility provides the execution environ ment for the protocol interfaces When the protocol inter face runs it communicates with ports other protocol inter faces and other C programs through HP UX message queues Using a description of the protocol interface s as sociated I O ports the run time facility manages the ports message queues process startup and process shutdown State Tables Documentation User Written an Test Cases Es Executable x y Test Results Protocol Interface Fig 3 HP DIS testing facility Application Process Step 1 Describe the Interface Step 3 Test Represents an HP UX io D Fig 4 Steps in protocol interface development using HP DIS The development and run time facilities also provide the following features A contributed library of example protocol interfaces tutorial protocol interfaces and other helpful tools The ability to implement user defined lookup tables Eight bit native language support Access between multiple devices and multiple interfaces The ability to a
151. l precision tools for HP 9000 computers Irene earned a BS degree 1981 in industrial en gineering trom the University of Wisconsin and an MS degree 1987 in electrical engineering trom Camegie Melion University in Pittsburgh Before joining HP she worked with Unimation Westing house in Pittsburgh to develop robotic systems Born in Racine Wisconsin Irene lives in Cupertino California For many years she has been a die hard runner and enjoys meeting other HP people through her membership in the HP Running Club John U Frohlich culator based systems to tes LED display devices Healso has worked on several versions ol the RTE operating system tor HP 1000 computers and on ATS 1000 software John received his BSEE de greein 1963atthe L College o Tech nology in Switzerland He is a member of the IEEE Born in Switzerland he lives in Cupertino Califor nia and enjoys mountain hiking biking and listen ing to old jazz recordings L C Measurements Asad Aziz Now a marketing account manager for HP s Circuit Technology Group Asad Aziz was previously in R amp D where he worked on the de sign layout modeling and electrical model verification of the PCX CPU package Before that he worked on packaging R amp D for HP PA RISC computers and on TAR design and electrical modeling Asad joined HP s Colorado Integrated Circuits Division in 1985 shortly after he graduated from Brigham Young Univer
152. le because it simplifies the system design Performance An HP DIS system is easier to construct than a similar application in C code but this is achieved with some loss of performance compared to C code In an HP DIS system functionality is split across five or more separate HP UX processes In C code all the functionality could reside in a single process For example HP DIS port management is handled by separate read and write port processes with PI DEFINITIONS Runtime Name Device xx Runtime Type T Runtime Name PMDPSS Runtime File Name usr bin PMDPSS Device Simulator Runtime Type T QUEUE DEFINITIONS Queue Name 01 02 03 04 05 Queue Link 95 gt Device xx Device xx gt Q3 Q4 lt Device xx Device xx lt Q2 PMDPSS lt Q3 PMDPSS gt 02 gt PMDPSS Fig 12 Test configuration file 70 HEWLETT PACKARD JOURNAL OCTOBER 1990 Runtime Name Device xx Execution Number 1 Case Number 1 Status Cases identical in fle Device xx tr and file Device xx da Event Path taken and Case Status in file Device xx tr IDLE send message DCIO DCMOVE DCMOVE DCMOVE DCMOVE DCMOVE DCMOVE DCCKSUM DCIO DCMOVE DCCNTR DCCLOCK WAIT Case Status 0 Event Path taken and Case Status in file Device xx da IDLE send message DCIO DCMOVE DCMOVE DCMOVE DCMOVE DCMOVE DCMOVE DCCKSUM DCIO DCMOVE DCCNTR DCCLOCK WAIT Case Status 0 Execution Number 1 Case Number 2 Status Cases identical
153. lected RF sections produ isamember of the IEEE and is the program chair man of the local subsection Born in Chicago II linois Bob is married and resides on Riebll Moun tain near Santa Rosa Calilornia His interests in clude sailing on San Francisco Bay and near the Northern California coast and volunteer testing of emergency beacons for NASA s Search and Rescue Satellite SARSAT including the HP mixers Before 59 Hexagonal Ferrit Dean B Nicholson For the past eight years Dean Nicholson has grown barium ferrite single crys tals processed them into spheres and designed fi ters using the spher Since he joined HP s Micro wave Technology Division 1980 he has also been terizing alumina and sapphire substrates He re ceived his BS degree in 1980 with dual majors in electrical engineering and materials science en gineering from the University af California at Berke ley Dean is an author or coauthor of four technical papers on barium ferrite tuned filters and oscil Jators He is named an inventor an a patent on the four sphere filter configuration that is part of the HP 11974 spectrum analyzer RF sections product Born in Orange California Dean is married has three daughters and lives in Windsor California He enjoys diving hiking and camping 62 HP DIS Kent L Garliepp Specializing in computer aided manufacturing Kent Garliepp worked on de sign
154. led a substate For example mov ing forward or backward in a sequence of actions that are part of one particular operation such as creating a polyline is controlled entirely by the state itself The substate mech anism is described later in this article State Stack Management During the execution of HP IVIBuild the states that are activated by the user are organized in a LIFO last in first out stack see Fig 5 The state machine provides a mech anism to suspend operations in progress to do another op eration and then resume the suspended operation when the new operation finishes The state at the top of the stack represents the current context of the user s input and is the current state Only the current state can receive any messages The maximum depth of the state stack is defined to be ten states This is an adequate depth because there are other mechanisms in HP IVIBuild that prevent the state stack from growing to a depth of more than three or four states The root state enters the state stack first and remains there during the entire execution of HP IVIBuild Therefore the root state is always in the stack regardless of the depth of the stack At each interstate transition the state machine checks the autotermination flags of each state in the state stack If the autotermination flag is TRUE that state is terminated immediately by the state machine and removed from the state stack The state stack is then compacted and the
155. m the University of California at Los Angeles Ravi is a member ol the board of directors of a local Hindu community and cultural center anda Sun day school teacher Born in Srinagar Kashmir India heis married has wo children and resides in San Jose California He enjoys jogging garden ing hiking and reading David W Quint Before Dave Quint joined HP s Desktop Computer Di vision in 1979 he helped design nuclear reactor control systems for Westing house Bettis Atomic Power Laboratories As an HP R amp D design engineer he developedtape automated bonding TAB and pin grid array PGA packaging for VLSI circuits He is now an R amp D engineer working on integrated circuit packaging at HP s Colorado Inlegrated Circuits Di vision Dave s work has resulted in two patents one describing a method of sampling a 100 GHz opti cal pulse stream and another for a method of de positing tungsten for integrated circuit intercon nects His professional interests include integrated circuit process engineering electromagnetic fields circuit analysis and optical electronics He published a paperin the Journal ol Applied Physics while at MIT and has coauthored three conference Papers on electronic packaging He received his BSEE degree in 1972 and MSEE degree in 1976 rom the University of Wisconsin at Madison and earned a PhD degree in 1979 from the Massa chusetts Institute of Technology Dave served as a weather observer inthe
156. magnet pole tips con nected by a very short transverse waveguide Fig 10 This four sphere filter configuration does not increase the mag net pole tip separation but in theory should double in dB the insertion loss off resonance isolation and image rejection of the two sphere filters previously built To simplify the mechanical design sphere mounts were machined from low dielectric constant plastic and epoxied over the irises Resonator spheres were then placed on the sphere mounts aligned and epoxied in place Fig 10 This sphere mounting technique allows accurate measurement of the sphere separation after mounting to determine sphere to sphere coupling The one significant difference that was expected in going to the four sphere design was the possibility of the two irises and the short transverse guide one wavelength long at approximately 80 of band forming a coupled cavity bandpass filter that might give a fixed frequency spurious et 20 30 40 50 60 70 of Band 0 10 Fig 9 Off resonance isolation of two sphere filters response When the first four sphere filters were turned on they gave the expected double in dB off resonance isolation insertion loss and image rejection as well as the cavity mode response Fig 11 By narrowing the width of the input and output waveguides and moving the spheres off center towards the center of the filter the one wavelength cavity mode can be pushed 5 to 6 GHz above
157. mension pace tends to dominate the The other window shows different sort of application Here the focus is on doi like setting up and running tests o IVIBuild is designed to create Because Interface Space dominates This ends up be ture king measurement the application looking very much like the older hardware products their users axe fatniliar with LLLLLL L tool boxes at a later stage in the development Colors were another area where the designers had some thing to contribute We had some color schemes in hand from our earlier work on widgets as well as from our work with HP s SoftBench product tricky decisions required to convey the 3D quality of This greatly simplified the widgets We provided the color names and RGB values that had to be assigned to each widget component to make the 3D effect work and provide a pleasant overall interface is applications like thi the three dimensio le word processing to this are spreadsheets uses black ink Fonts were also important Graphical user interfaces in general and the 3D widgets in particular are very much dependent on good fonts to be successful While the popu lar notion of a graphical interface centers on icons most and good pro The HP IVIBuild team decided to use some display fonts that had These fonts of the work is still done with words portionally spaced fonts make words work better been created by HP expressly for 3D widge
158. minimum gain from 220 corre lated simulations has a mean of 1 44 and a standard deviation of 0 04 It predicts a minimum gain specification of 1 33 to 1 57 OCTOBER 1990 HEWLETT PACKARD JOURNAL 79 1949 1998 Hewlett Packard Co registers can program the gain from 1 5 to 12 5 in 3 incre ments Projection of Manufacturing Specifications In the manufacturing release of this IC no reliable data was available to set the minimum gain specification 1 5 nominal of the programmable gain circuitry shown in Fig 2 This gain cell can be programmed to amplify small sig nals with a nominal gain of 1 5 to 12 5 Aninaccurate specification on the minimum gain would cause high parametric yield loss The statistical simulation techniques described previously were carried out to project the gain distribution in a real life manufacturing environ ment For these simulations 36 circuit elements were iden tified as random variables The correlation coefficients of these variables were compiled from production data for the HP5 process Specifically the following intradie device correlations were accounted for Correlations between resistors Correlations between transistor model parameters m Correlations between resistors and transistor model pa rameters A 200 sample Monte Carlo simulation was carried out The simulated minimum gain distribution is shown in Fig 3 It projects a 30 specification of 1 33 to 1 57 Measured prod
159. mory allocated for the object Arglists can also be freed using the function ZtFreeArgList This function will free all memory associated with the Arglist including the additional memory allocated for attributes Manipulate Attributes Most attributes of existing objects can be modified For example in an application in which a text object contains a string that indicates elapsed time the time needs to be updated periodically ZtChange can be called passing the new value of the elapsed time in the ZtSTRING attribute of the object Arglist ZiChange also provides a way to modify several objects in one call The user simply has to put all the desired objects into a list and issue a ZtChange call on the list object The changes will be made to all objects that the list refer ences In the following code fragment the foreground color is changed for all objects referenced by the identifier listid arglist for foreground color static ZtArgListitem fgcArglist ZIFOREGROUND COLOR NULL int return vai fgcArglist O ZtValue ZtValueType steelblue Steelblue is the index into the system object s color list theZICOLOR LIST attribute on the ZISYSTEM_OBJ change the colorto steelblue y return val ZtChange listid fgcArglist NULL ZtValueType NULL ZiValueType NULL Default values can also be changed with the same call To change the value of a default attribute the object type and not the objectid must be
160. nally over widgets the x y coordinates of the event are recalculated to be relative to the API window object before dispatching Recalculation of widget points is done because the API understands points relative to the window object coordi nate system and not to the widget coordinate system Event Grabbing For customers making their own user interface builders and also for HP IVIBuild a feature was needed to direct events only to the window For example the normal be havior for a widget pushbutton object is to flash when it is selected However in the builder selecting the push button may be the start of a move operation on it To sup press normal widget behavior and let the application deter mine the meaning of the event a button press event over a widget has to be directed only to the window object The event has to be grabbed To solve this problem input han dling at the server object level was modified so that if event grabbing is enabled the event is only sent to the window object for processing Window Expose and Resize When Expose and ConfigureNotify events occur on API win dow or graphics objects special functions are called in the server object to handle these events Since graphic objects are not in individual X windows as the widgets are see Fig 8 the window object has to redraw the graphic objects when an Expose event occurs and resize its children when ConfigureNotify event occurs Foran Expose event t
161. nce The capacitive impedance dominates the current so the resistive and inductive volt Wirebond PGA Trace Plating Stub PGA Pin and Via 12pF PGA 32nH 50 mi 0 08 nH 0 49 nH Signal Pad 29nH 100 Node 3 Node T2 0 30 pF 0 30 pF 74 HEWLETT PACKARD JOURNAL OCTOBER 1990 Pd Rus o 5 wana 3 4 pF Fig 2 Passive circuit model of a typical PGA signal trace structure showing typical trace parameters Nodes T3 and T4 are correspond ing nodes on the adjacent signal trace for capacitive coupling In ductive coupling is not included in this model Copr 1949 1998 Hewlett Packard Co ages can be ignored In addition the capacitive loading on the Vow side is of little consequence because the voltage being measured the plateau top is essentially constant The capacitance on the side will drop out of the mea surement equation if the time constant is much less than the test pulse rise time C can be measured quite easily at several pulse rise times and the calculated values of C can be compared for the different measurements The longest pulses will give smaller plateau voltages increasing the importance of the signal to noise ratio of the equipment while the shorter pulses will cause the measurement to depart from its true value in a systematic way as the parasitics in the test jig become more dominant In the PGA and other common packages there is usually a wide range of
162. ndow p 0 25 0 25 Pi 0 0 0 5 9 0 25 0 5 0 0 Window T 0 192 255 192 255 383 _ 512 Pixels Fig 10 viewable area the world coordinate window is defined to the upper right quadrant of the display b Results of applying the x and y scale factors to the pushbutton coordinates c Results of applying translation factors to the scaled pushbutton coordinates d Results after applying the flip factor tc compensate for the X window origin in the upper left corner of the NDC space e Results after transforming the pushbutton from NDCSs to DCs 26 HEWLETT PACKARD JOURNAL OCTOBER 1990 1949 1998 Hewlett Packard Co Every window object contains a viewport to window transformation matrix VTM This matrix describes how to scale and translate the viewable WC region to fit within the window A scale factor SF is calculated to scale the WC width and height to the width and height of the view port This scale factor for the x coordinate is SF width of the window in NDCs width of the viewable WC region in WCs and for the y coordinate is SF height of the window in NDCs height of the viewable WC region in WCs For example in Fig 10a the viewable area of the world coordinate window is defined to occupy a viewport in the upper right quadrant of a display The scale factors for mapping the WC region to NDCs in this example are SF
163. ndow interactively and the objects to be redrawn without the intervention of the appli cation Changing the size of the window changes the NDC definition of the window This change causes the scaling factors in the VTM to be recalculated at the next display pass The objects are either enlarged or shrunk to fit within the new window size When resizing a window the user may change its aspect ratio That is the physical width to height ratio of the object may be different from the WC width to height ratio When this happens objects begin to look distorted For instance a circle begins to look like an oval This may be an appropriate action for some applica tions but for others especially those where the objects on the display are meant to represent something in the phys ical world the application developer wants the objects to maintain their width to height ratio In graphics packages these two modes of operation are referred to as anisotropic and isotropic scaling respectively The API window object provides the attribute ZtADJUST which the application can 28 HEWLETT PACKARD JOURNAL OCTOBER 1990 set to ensure that the aspect ratio is maintained If this attribute is set and the window is resized the WC height or width mapping to the window is adjusted to maintain the original aspect ratio This process results in modifying the scale factors stored in the VTM This also results in more viewable WC space in the window in either the x o
164. ned to desensitize it to the process defect The dis tribution from one wafer after redesign is compared to the simulated distribution in Fig 7 The redesigned circuit shows a mean of 6 mV and a standard deviation of 4 8 mV The simulated values are close to the initial production data The slight discrepancies of the standard deviations can be accounted for by a variety of second order effects that were not included in these simulations most notably variations in metal resistivity and metal to metal contact resistance 204 154 10 s 04 10 o 10 20 30 Output Otfset mV 200 150 100 50 E l 4 10 o 10 20 30 b Output Offset mV Fig 7 a The distribution of the output offset voltage of the op amp from 200 correlated simulations has a mean of 11 mV and a standard deviation of 3 4 mV very different from the production data shown in Fig 6 b The distribution from one production wafer after redesign has a mean of 6 mV and a standard deviation of 4 8 mV more closely matching the simulation data Conclusions This statistical circuit simulation study has demonstrated the accuracy of this technique in projecting circuit perfor mance distributions in manufacturing The technique also has a valuable role as a diagnostic tool for troubleshooting process problems Despite some assumptions used both in the underlying principal component analysis theory and the device modeling these simulations are accurate
165. not possible to model every single component in the system Since the main focus for this project was on system level characteris tics a component level simplification in the metry was To model the components on the boards it was made Fig 2 A view of the finite element esh for simulation of the air flow n HP 9000 Model 850 SPU The complete mesh consists of 60 507 nodes and 48 600 8 node brick elements T PACKARD JOURNAL 83 Copr 1949 1998 Hewlett Packard Co COMPUTER AIRFLOW AT ASSEMBLY LEVEL CRAY SIMULATION VELOCITY VECTOR PLOT SCALE FACTOR 0 1000 03 VECTOR PLOTTED 0 5064E 01 AT NODE 61127 HS PLANE COEFF S 0 000E 00 0 100 01 C 0 000 00 VIEW DIRECTION VX 400E 04 VY 0 300 00 0 B00E 00 ANG 100 03 Fig 3 Computed velocities FIDA 454 in the X Z plane at the entrance to 17 48 02 the printed circuit boards assumed that between any two printed circuit boards a certain percentage of the flow passage was blocked by com ponents Based on good engineering judgment for the four CPU printed circuit boards the blockage was assumed to represent 30 of the volume between two adjacent boards whereas for all the other boards the blockage was assumed to represent 50 of the volume between adjacent boards Flow deflection vanes at the air inlet of the cabinet were included in the model as infinitely thin plates at
166. ns are geomet ric transformations such as scaling rotation and transla tion movement This feature allows the user to draw an object and then reuse it in the picture by moving scaling and rotating it to fit the requirements of the picture These three coordinate systems and the modeling trans formations are linked together when an object is drawn First the object is transformed by its modeling transforma tions to the desired orientation in the world coordinate system The world coordinates are scaled and translated to fit into the viewport and converted to normalized device coordinates Finally the normalized device coordinates are converted to device coordinates to draw the picture in the viewport These transformations are shown in Fig 2 Widgets and Xt Intrinsics The widgets pushbuttons scrollbars etc and the Xt Intrinsics provide the basis for the API input model and for other API features The API project team took the input loop from Xt Intrinsics and added processing to handle API graphics objects Also leveraged from the Xt Intrinsics are the methods for getting file descriptor input and time outs An extension of the Xt callback technique allows users to attach functions to window objects to handle X events and to API graphic objects which include geometric figures such as circles arcs and rectangles to handle mouse button events To keep the number of API functions low API parameter handling is patterned after
167. nted toolkit are in the article on page 11 and the design of the application program interface is the subject of the article on page 21 In the article on page 39 we re told how the HP IVI editor s own user interface was refined and given a 3D appearance with the help of a team of industrial designers The other CIM software product in this issue is HP Device Interface System or HP DIS It addresses the problem of efficiently developing interfaces between computers and factory floor devices like robots programmable controllers and machine tools This is a problem because these devices typically come from many manufacturers and have different proprietary interfaces HP DIS is a toolkit that helps application software developers create and test interfaces between HP 9000 computers and factory floor devices Its development facility provides a high level lan guage for specifying communications protocols Its testing facility provides a test generator a test exerciser and a device simulator that makes it unnecessary to have actual devices to test interfaces The HP DIS run time facility executes protocols in real time The design and perfor mance of HP DIS are described in the article on page 62 4 HEWLETT PACKARD JOURNAL OCTOBER 1990 Copr 1949 1998 Hewlett Packard Co Simulation is an important part of many design processes because it makes it possible to refine a design without actually building anything provided that the computer
168. o models which are templates or libraries of previously created work Fig 4 shows the utility box and tool boxes at an early point in the design stage of HP IVIBuild The Workspace This is the area in which the user does the work of building a user interface In this area graphic or widget objects are put together on a kind of three dimen sional sheet of paper After assembly they are stored away for use as finished products or as models for reuse or mod ification For example a simple dialog box might be used as a template for other dialog boxes eliminating the need to start each one from scratch Collaboration The early efforts by the industrial designers focused on sorting out the functionality found in each of the HP IVIBuild areas and then finding reasonable ways of present ing each area The utility box and the tool box visual layouts received the most attention One of the first steps was de termining the menu structure in the utility box Certain conventions and many examples exist in industry showing how applications organize and perform activities like edit ing and filing for example the locations of commands like cut copy paste and quit in a word processing package And certain conventions exist in terms of dialog box layout like where the OK cancel and help buttons should go We followed accepted general practices wherever possible and tried to develop acceptable solutions where no previous models existed The t
169. ocesses and assisting with crystal growth Without his help the project would have been immeasurably more difficult In addition I would like to thank Jerry Gladstone for management sup port even when the success of the project seemed uncertain at best References 1 B Lax and KJ Button Microwave Ferrites and Ferrimagnetics McGraw Hill 1962 pp 164 165 2 HipercoR 50 Specifications Carpenter Technology tion 3 G Winkler and H Dotsch Hexagonal Ferrites at Millimeter Wavelengths Proceedings of the 9th European Microwave Con ference 1979 pp 13 22 4 P Roschmann Lemke W Tolksdorf and F Welz tropy Fields and FMR Linewidth in Single Crystal Al Ga and Sc Substituted Hexagonal Ferrites with M Structure Materials Re search Bulletin Vol 19 February 1984 pp 385 392 5 W Tolksdorf On the Preparation of Polycrystalline Zn Ba Fe 02 Especially With Respect to Added Bi O IEEE Transactions on Magnetics Vol MAG 2 no 3 September 1966 pp 472 473 6 F E Reisch R W Grant and M D Lind Magnetically Tuned Zn Z Filters for the 18 40 GHz Frequency Range IEEE Transac tions on Magnetics Vol MAG 11 no 5 September 1975 pp 1256 1258 7 G P Rodrigue Magnetic Materials for Millimeter Wave Appli cations IEEE Transactions on Magnetics September 1963 pp 351 356 8 J Helszajn YIG Resonators and Filters John Wiley and Sons 1985 pp 101 102
170. of 325 MHz and off resonance iso lation greater than 30 dB The spheres were aligned on beryllia rods which were slipped into holders that allowed 0 1 mm of sphere adjustment from side to side and up and down in relation to the iris The sphere rods were inserted through the reduced height sidewall of the waveguide so that it was possible to center the spheres exactly over the iris and to move them closer together or farther apart to change the sphere to sphere coupling In Fig 7 the response of this filter is shown centered at ap proximately 48 5 GHz and moved up by 4 5 dB so the off resonance isolation can be read easily off the plot The low frequency side of the filter s response cuts off more quickly than the high frequency side and 650 MHz away from the peak of the passband the rejection is about RF In RF Out Fig 5 A single stage of a typical YIG filter 52 HEWLETT PACKARD JOURNAL OCTOBER 1990 Magnetic Field Lines Fig 6 Two sphere waveguide bandpass filter 35 dB The rejection of a filter 650 MHz away from the peak is important for preselection applications because the IFs used in the HP instruments are approximately 310 MHz and 321 MHz An unpreselected mixer will display an image signal at the same amplitude as the true signal at two times the IF away from the true signal Therefore much of a filter s usefulness depends on its image rejection which is a measure of how much this unwanted trace is suppr
171. of the time might only implement the method that draws the representation of the clock and inherit the more basic functions e g audible alarms from the more general digital clock class Inheritance allows object definitions to be shared rather than copied and customized by extension rather than by modification A goal of object oriented design is to organize object definitions so that common behavior is specified in shared definitions and object definitions can be extended The external representation of the class hierarchy that is pro cessed by the OOE class compiler tool builds tables of function pointers Entries that are not NULL in these tables indicate that a particular class implements a particular method NULL entries indicate that a particular class inherits a particular method The class compiler also declares a pointer to the class s parent in the hierarchy see Fig 4 The OOE messaging routines use this information to traverse upward in the class hierarchy when searching for a method In object oriented systems classes may have one parent or many Single inheritance allows a class to have only one parent This is the model implemented by the OOE Object oriented lan guages such as Smalltalk and C allow classes to have more than one parent This is called multiple inheritance Pam Munsch Project Manager Industrial Applications Center Steve Witten Development Engineer Industrial Applications Center be
172. ology Conference Hewlett Packard Company pp 324 331 Additional information can be found in 4 D W Quint and Asad Aziz Electrical Design Methodology of a 407 pin Multilayer Ceramic Package Proceedings of the 1989 Electronic Components Conference Hewlett Packard Company pp 392 398 5 Perezalonso B Crawford R Kaw and R Bernard Investi gation of R L and C Measurement Techniques for VLSI Packages Hewlett Packard Company September 1988 Published as Elec trical Characteristics of VLSI Packages Proceedings of the 1989 Design Technology Conference Hewlett Packard Company pp 110 119 OCTOBER 1990 HEWLETT PACKARD JOURNAL 77 Copr 1949 1998 Hewlett Packard Co Statistical Circuit Simulation of a Wideband Amplifier A Case Study in Design for Manufacturability Statistical variations of integrated circuit parameters are often correlated not independent Examples are side by side resistor values and matched transistor gains Accounting for these correlations using principal component analysis can make statistical simulation an accurate predictor of manufacturing data by Chee K Chow statistical circuit simulation that can accurately project circuit performance distributions in manufacturing There are two reasons for this need First being able to project the performance distributions precisely in the de sign phase enhances the chance of a first pass success Thus the cycle time f
173. olor Window Row Column Menu Button Font Model Scroll List Pushbutton Raster Scrollbar Input Data Text List Text Edit Point Toggle Button Transform Graphics Polyline Line Rectangle Square Circle Ellipse Arc Spline Text Label Fig 2 API object groups 12 HEWLETT PACKARD JOURNAL OCTOBER 1990 Polymorphism and API One of the key features of object based systems is the concept of polymorphism Polymorphism allows different objects to share a common operational interface operations with the same name When an operation is invoked the function dynamically determines the object type and exe cutes the appropriate code Object oriented programs are polymorphic because they can operate on many different object types with the same functional interface This com mon interface provides a great deal of flexibility and ease of use to the API programmer Common access reduces the number of functions and increases the power provided by the basic set of functions The API functions provide the functionality of polymorphism through an identifier called Ztld When an object is created via the ZtCreate function a Ztld is returned from the call for use in further operations The Ztld is a pointer to the object that was just created This handle allows the programmer to reference the object when addi tional modifications are necessary The API functions use this identifier to determine the type of object being
174. om putationally intensive with the emergence of widely avail able high performance workstation class computers they can be routinely performed A typical 200 sample simula Statistical Package Usar Input Circuit Element Correlation Matrix ni Principal Component Analysis Correlated Vector Generation HP Spice Text File Generation HP Spice Simulation HP Spice Simulator HP Spice Text Files Fig 1 Statistical circuit simulation algorithm Voltage Fig 2 Simulation was used to set the minimum gain specifi cation for this programmable gain circuit portion of an inte grated amplifier IC tion takes 149 seconds on an HP 9000 Model 370 worksta tion Case Study The merits of this statistical circuit simulator are illus trated by two applications during the manufacturing re lease of a custom high speed integrated circuit The circuit is an integrated amplifier fabricated using the HP5 process a 5 GHz fr oxide isolation process The IC is used in the HP 54503A low cost high performance digitizing oscilloscope This custom IC is the heart of an amplifier attenuator assembly that accurately reproduces signals from dc to 500 MHz and from 40 mV to 40V with ac or dc coupling and a constant output dynamic range of 500 mV The IC consists of nine functional blocks On chip a 1 30 1 35 140 145 1 50 155 Minimum Amplifier Gain Fig 3 The distribution of the
175. on sheet resistance were between 5 and 7 milliohms square well below the maxi mum specification of 13 milliohms square In addition the resistance of the ground and power supply routing was less than 5 milliohms which was not considered signifi cant The inductance measurement results were as follows Parameter Measured Calculated Difference Self L uppertier 15 1nH 15 2nH 196 Self L middle tier 14 9nH 14 6nH 296 MutualL middletier 3 64nH 3 21nH 12 Mutual L upper tier 4 7 nH 4 5 nH 496 WB coupling 1storder 2 0nH 2 1nH 5 WB coupling 2nd order 1 4nH 1 5nH 7 Note WB wirebond The sources of error for the signal inductance parameters are 1 the routing on the chip 2 variations in the length and the shape of the wirebonds and traces and 3 imper fections in the ground planes The capacitance measurement results were as follows Parameter Measured Calculated Difference Self C upper tier 10 1pF 9 5pF 6 Self C middle tier 6 5pF 6 3pF 396 Mutual C upper tier 0 7pF 0 5 29 Mutual C middletier 0 6pF 0 5pF 17 The sources of error in the signal capacitance measure ments are 1 the capacitance of the pin braze pads and 2 the capacitance of the vias and the associated cover dots The capacitance between the wirebonds and between the pins was found to be less than 0 1 pF and has been ignored Power Supply Models The measurements were done in the same way as for the signal traces T
176. onding tiers on the package are exclusively for signal or I O connections The bottom bonding tier is reserved for power supply and ground connections The signal routing layers provide a stripline environment and there is a ground plane adjacent to each of the power supply planes The pads on the chip are spaced at an effective pitch of approximately 110 micrometers 0 00433 inch We have been able to match this pitch on the package by using two signal bonding tiers Power supply connections are divided into eight groups for flexibility and noise isolation The T HE NEED FOR HIGH PERFORMANCE high pin Bottom Bonding Tier Middle Bonding Tier Top Bonding Tier Dielectric Layer 1 TL 1 Dielectric Layer 2 TL 2 1 Dielectric Layer 3 TL 3 Dielectric Layer 4 TL Dielectric Layer 5 Dielectric Layer 6 chip mounts directly on a copper tungsten heat spreader that is used for heat dissipation The heat spreader is also connected to ground Electrical Modeling The designers of system processing units put considera ble effort into system simulations One of their main con cerns is the amount of noise induced on logic Vpp logic Vpn powers the internal circuitry of the IC and logic GND ground Another concern is noise on signal lines Noise is caused by power and ground bounce and by coupling of signals from one line to another The main source of this rioise is the familiar Ldi dt term which arises from logic and 1
177. ons and requests to Editor Hewlett Packard Journal 3200 Hillview Avenue Palo Alto CA 94304 U S A OCTOBER 1990 HEWLETT PACKARD JOURNAL 3 Copr 1949 1998 Hewlett Packard Co Our cover subjects this month can barely be seen in the cover photograph They re the two tiny specks in the middle of the flat plate in the foreground x They are spheres of barium ferrite that serve as the frequency sensitive elements of magnetically tunable bandpass filters for the millimeter wave romagnetic spectrum from about 30 to about 300 gigahertz It s becoming more important as radar communications and other systems move to higher frequencies seeking higher performance or less crowding These filters are mi hau 1 used as preselection filters in the HP 11974 Series preselected mixers a family of four mixers designed for down converting millimeter wave signals from the 26 5 to 75 GHz range into the frequency range of compatible HP spectrum analyzers The preselection filter removes unwanted image and multiple responses natural consequences of the mixing process that clutter the spectrum analyzer display and obscure the desired response In the microwave frequency range below 30 GHz yttrium iron garnet YIG spheres have been used as resonators in such filters but at higher frequencies tuning magnets for YIG spheres begin to pose design problems so a new material was needed A new four sphere filter design was also found necessary
178. ontribute unwanted voltages to the measurement Test Fixture and Parasitics For each of the parameters that we measured inductance capacitance mutual inductance and mutual capacitance we had to build a different set of probes The parasitics of Von Roen E V Voon v t Time ns Fig 4 Inductance measurement circuit and voltage wave forms OCTOBER 1990 HEWLETT PACKARD JOURNAL 75 Copr 1949 1998 Hewlett Packard Co these probes were zeroed out before and after each measure ment to make sure that the characteristics of the probes did not change during the measurements This was espe cially important in the case of the power supply inductance measurements because the characteristics of the probes were comparable in magnitude to those of the package Signal Models Signal trace models were calculated using Stripcal to calculate the lumped elements in the trace model between the PGA bond pad and the base of the pin Ind3 was used to calculate the inductances both self and mutual for the wirebonds The measurements were done on a 408 pin PGA that had a test chip mounted and bonded in it For the inductance measurements all the wirebonds were shorted together on the chip For the capacitance measure ments all the signal wirebonds were isolated Resistance measurements are not discussed in detail be cause they are straightforward and because the measured values of the tungsten metallizati
179. ool box with its various modes was probably the most complex job The final layout chosen for the tool box owes many of its approaches to showing status and offering choices or functions to existing de facto standards for paint programs There were instances where we were forced by technical limitations to deviate from these standards For example a simple draw tool like the one used to draw a rectangle typically requires a decision about whether the rectangle is to be filled in or left as an outline A typical solution is to have one button with a rectangle on it with the left half hollow and the right half filled what looks like one button is in fact two buttons In our case the widgets wouldn t allow that approach so we ended up with a separate button to turn the fill function on or off Fig 5 shows the design recommendation for the utility and OCTOBER 1990 HEWLETT PACKARD JOURNAL 41 Copr 1949 1998 Hewlett Packard Co This is a typical document Other t charting and grap ion windo of applications which would be programs various drawing end rograms desktoy ll ss CAD programs All of these plications as well be WYSYWYG character and the final product of using dimensional piece of paper It is therefore entirely sppropriate that the User Space in wh creation resembles the final products sheet of paper It is large whit etc Unless of course itis an application that crestes colored docum that two di
180. orders lines and fills e g ZIFILL_TILE ZIBACK GROUND TILE ZtLINE WIDTH Attributes that define a widget s appearance e g ZtSHADOW ZIBOTTOM SHADOW COLOR ZITOP SHADOW COLOR Attributes used to attach user defined functions to an object These functions are used to respond to user input For example ZtREASON specifies when a callback function should be called and ZICALLBACK FUNC TION specifies a function for processing user input Attributes that affect or define the current API object hierarchy e g ZICHILD LIST ZICURRENT MODEL Parenting Keyboard Traversal Attributes that assign the input focus to an object e g ZITRA VERSAL ZINEXT TOP WINDOW Function Attributes that affect the capa bilities of functions e g ZIRE CURSIVE ZtMERGE API Functions Because of polymorphism a minimum number of API functions are required for manipulating API objects Polymorphism allows the same API function to be used to handle more than one object Table II shows the API func tions available for manipulating the object groups shown in Fig 2 Table Il Categories of API Functions Function Use Function Names Createand Free Objects 21 ZtCreate ZtCreateList ZtFree Manipulate Attributes ZtChange ZtQuery Saveand Restore Objects ZtSave ZtRestore Locate Objects ZiFindByAttribute ZtFindByLocation Receive Input ZtDo ZtINPUT Perform Visual Updates ZtDo ZtDRAW
181. oriented programming A member of the Institute of Industrial Engineers his profe sional specialty centers around object oriented technology He received a BS degree n computer science in 1974 and an ME degree in industrial en gineering in 1976 from the California Polytechnic State University in San Luis Obispo Born in Bakersfield California Steve is married has two daughters and lives in San Jose His hobbies include computers and reading detective novels Hai Wen L Bienz Hai Wen Bi sponsible for the develop mentof the graphic objects and dynamics in the HP IVI application program inter lace She joined HP in 1985 and served as a publica tions engineer at HP s Santa Clara Division and later as a marketing en Gineer for the Strategic Grants program at HP Laboratories Hai Wen s professional interests in clude designing user interfaces and software tools 1o enhance productivity Before joining HP she was a coop student and engineer at General Motors Corp where she developed real time digital con trol systems Hai Wen earned a Bachelor s degree n electrical engineering from the General Motors Institute in 1983 and an MS degree in electrical gineering from the University of Illinois at Urbana Champaign in 1984 She is married and lives in Naperville Illinois Her interests include moun taineering skiing photography cooking and hiking enz was re 39 HP IVIBuild User Interface Steven R Ander
182. ork done on the subject Verifying that these models were cor rect was much more challenging and is the main topic of this paper Models were verified by comparing package parameters calculated from the models with measurements on an actual PGA package Most high frequency measurements are done using a net work analyzer or a time domain reflectometer TDR Both instruments measure reflections from discontinuities The problem with using a TDR lies in the interpretation of the results when the time delay through a discontinuity is short compared with the rise time of the propagating pulse The PGA package signal leads consist of stripline transmission lines with a signal propagation time between 100 and 200 picoseconds and a characteristic impedance of approxi mately 37 ohms Considering the time delay through the package a TDR pulse with a rise time of about 20 pico seconds is necessary to give good resolution Using such a fast rise time skin effect dielectric losses and reflections from the test fixture and interconnections distort the reflec tion test signals to such a degree that it is virtually impos sible to extract an RLC circuit for the package itself A TDR measurement also does not give numbers for first order and second order mutual inductances and capacitances be tween signal lines TDRs are especially unsuitable for the power supply planes because of the extremely low charac teristic impedances of these planes 50 or less
183. ot only uses conventional widgets to create a graphical user interface but it can also create graphic objects that behave like widgets What this means is that buttons and scrollbars can be supplemented with graphic representations of ob jects that can change to reflect current status For example a graphic image of a storage tank can change to show the current level of the liquid it contains or an assembly line schematic can be changed to reflect the status of each work cell The output of HP IVIBuild can range from simple windows with menu bars and dialog boxes to very complex control panel like layouts with animated graphics and numerous controls These capabilities were not obvious in the original interface shown in Fig 3 The Structure of HP IViBuild The HP IVIBuild user interface is divided into three parts a utility box a tool box and a workspace The Utility Box This area holds the menu bar a prompt window several status indicators and some commonly used commands in the form of pushbuttons The Tool Box This area is like a palette of various graphic or widget creation tools It has three modes graphics widgets and models The graphics mode functions like a typical paint program displaying numerous drawing tool buttons as well as mechanisms for displaying and selecting items such as colors patterns and line weights The widget mode is used for creating and specifying the widgets The models mode is used to get access t
184. ounter Events TimeOut internal time counter gt 60000 State Table DcClock 1 time counter 1000 Starttime counting Time outdetected Stop time counting Idie TimeOut DcClock 2 time counter Idle messages state event pairs and values of all variables after every action associated with each state event pair The vari able values are useful for checking the results of actions even when the correct path is executed This example has shown that by using tools and a subsys tem approach a factory floor device protocol can be mod eled and produced Configurations Fig 15 shows various configurations for HP DIS built interfaces Interface schemes can use a single protocol in terface or multiple protocol interfaces These protocol in terfaces can be stacked in series or configured in parallel When multiple devices are serviced even more choices can be made each device can be serviced by its own dedi cated protocol interface or multiple devices can be ser viced by a generalized protocol interface Fig 15a shows the simplest configuration Here one pro tocol interface handles one port and one device Fig 15b shows three protocol interfaces that work to gether Message processing that is common to all ports is done in the lower level PI1 The message is passed to the upper level PI2 and for device specific processing For example PI1 can collect all messages from multiple de
185. oyment and HP IVI Quality tunction deployment QFD is an analytical method ot collecting and analyzing subjective and objective data about customer needs and wants It is one of the methods the HP IVI project team used to determine the minimum feature set required by our target customers QFD was chosen because it facilitates not only the translation of customer wants and needs into product features but it also enforces consideration of methods to imple ment the features When the features are known the project schedule and required resources can be properly planned Since our organization HP s Industrial Application Center IAC was new it was easy to promote QFD as a viable technique because there were no traditions ingrained in the organization The QFD process is shown in Fig 1 The first step is to collect the customer needs data To get this information we visited many of the customers who represent our target market This took place over a period of about two months IAC teams of two or three members went out to each customer site Team personnel came from marketing R amp D and management These teams pre sented a broadly defined theoretical product to each customer focusing on how the product could make them more successful To get the spoken and latent needs out a loosely structured open ended questionnaire was presented as an aid for generat ing discussion Notes were taken to record as much data as possible The idea behin
186. p It sends messages to the current state It manages the state stack The state stack is an array of message selectors for the state objects m It makes new states current and terminates others that have completed The Current State There is always a state that is active This state is called Root State Fig 5 The state stack Copr 1949 1998 Hewlett Packard Co the current state The current state is always the state to which the state machine sends any messages It is up to the current state to provide a target method for any mes sages that the state machine may send it The target method is located either by implementation or by inheritance If no operation is in progress i e only one state on the stack the current state is the root state If an operation is in progress the current state is the state that implements that operation e g creation of an object such as a polyline or widget No state knows which state was current before it became current and no state knows which state will become current after it ceases being current These rules were strictly en forced to ensure the black box nature of each state s methods during design and testing Once current a state controls the context of the user s input according to a state transition mechanism of its own These state transition mechanisms are called intrastate transitions and are controlled entirely by the state itself using a local variable cal
187. p consists of an HP UX select call to see if input exists on either the user s file descriptors or the API server object s file descriptors and a test to see what events came in see Fig 4 If input is pending on the file descriptor for the X server a message is sent to the API server object to process all X events queued If input is pending on a user s file descriptor the user s callback func tion is invoked The server object still does the XtNextEvent and XtDis patchEvent looping but it has additional code to handle conversion of X callback information to API format callbacks on graphic objects and window objects Expose and ConfigureNotfy events on window objects global callbacks and event grabbing see Fig 5 Callback Handling Callbacks are implemented as objects in the API These objects contain a pointer to the user written function to be called when an X event occurs a pointer to callback spe cific data and the specific reason that will cause the callback to invoke the user function see Fig 6 The file descriptor that is checked during input processing is an example of callback specific data The reason for the invo cation of the callback is an integer value that indicates the type of input event such as a button press These callback objects are put ina list called a callback list and are attached to the object requiring them For the Xt Intrinsics the callbacks are attached to specific reason resources instead o
188. r the y direction Applying the various coordinate systems to windows and widgets has worked successfully Specifying their po sition and size in NDC or WC units allows the user to define them in the same manner as graphic objects It also allows the application to be independent of the display and window size even as the user interactively resizes the window Scaling and moving widgets works the same as for graphics objects However as the widgets scale smaller and larger the font that they use does not scale because it is a bit mapped font The widget scales larger and leaves more space between the edge of the text and the edge of the widget or it scales smaller and closes in on the text even tually clipping it see Fig 11 A few possible solutions to this problem exist One solution is for the X Window Sys tem to support scalable fonts This will allow the font to scale with the widget Another solution is to switch be tween a set of fonts with different sizes as the object grows and shrinks Widgets also cannot rotate from a horizontal base In the API when a widget is rotated its defining point is rotated and the widget is redrawn in the new position with a horizontal base This allows the widgets to be rotated as part of a symbol and to move along with any associated graphic objects Despite these differences continued on page 30 Types of Files Class Header File e g circle h Class Definition File e g circle c
189. r application of simulation this time to predict the pressure drop and air flow characteristics in a computer system processing unit is described in the paper on page 82 In the past these quantities have been determined from measurements on prototype machines which are available only after most of the design has been done If the measured results are unacceptable major design changes may be required The study showed that using supercomputers and finite element modeling it is possible to simulate the air flow accurately enough to allow meaningful decisions early in the design phase R P Dolan Editor Cover The flat plate in the foreground is the iris plate from a magnetically tuned preselection filter used in the HP 11974 Series preselected mixers In the middle of the plate are two tiny barium ferrite resonator spheres Also shown are the top and bottom halves of the tuning magnet the magnet body and the two parts of the waveguide assembly What s Ahead In the December issue we ll have articles on the autochanger and servo design and system integration of HP s 20 Gbyte rewritable optical disk library system designed for direct access secondary storage Error correction software protection and system integration of HP s CD ROM drive will also be featured The data communications and terminal controller for HP 3000 computers running the MPE XL operating system now supports X 25 network packet assembler dis assemblers two articl
190. rnal data structures the rectangles may be drawn in different sizes colors and positions The OOE tool mentioned above is called the nc run time class information tool The ne tool compiles a symbolic external rep resentation of the class hierarchy into the data necessary for Fig 1 An object The internal data structure is private to the object and the methods have sole access to the data defining classes and methods for those classes The symbolic representation of the class hierarchy is compiled by the nc tool to produce static tables called dispatch tables which consist of two pieces a category table and method tables These tables contain information necessary to dispatch messages to objects A unique key called the message selector is used to search the dispatch tables for a pointer to a function that will service a request The nc tool also generates a file containing definitions of symbolic names for the constants that represent the message selectors Coding using the symbolic names for the message selectors provides independence from the structure of the under lying dispatch tables and provides more readable code The nc tool and the type of files it compiles and generates are described in more detail on page 31 Messaging Objects communicate with each other through mes saging Sending a message to an object requests that object to perform some action usually the manipulation of its internal data Messages consist of a m
191. rom the design phase to manufactur ing release can be significantly reduced Second simula lion can serve as a diagnostic tool to identify hidden process problems For example large discrepancies between the simulated and manufactured distributions frequently indi cate process anomalies not previously discovered A simple approach to statistical circuit simulation is to perform a large number of Monte Carlo simulations The inputs to these simulations are computer generated ran dom circuit parameters based on the means and standard deviations of the circuit elements extracted from the man ufacturing data A significant drawback of this approach is that it does not account for the highly correlated nature of the device parameters within an integrated circuit die and also among dice Consequently it rarely gives accurate predictions In integrated circuits device parameter variations are separable into two types Variations across many dice waf ers or fabrication lots are random in nature while those within a die are highly correlated Examples of the latter type are the side by side layouts of resistors and matched transistor pairs At present commercially available circuit simulators do not address these intercorrelations so they do not provide the information needed This article describes a circuit simulator study that ac counts for both the intradie device correlations and the lot to lot random variations The technique used
192. rs IEEE MTT S Interna tional Microwave Symposium Digest 1983 pp 130 132 3 M Lemke and W Hoppe Hexaferrite Components Tunabil ity at mm Waves Proceedings of the Conference on Military Mi crowaves London 1980 pp 95 100 4 D Nicholson High Performance Hexagonal Ferrite Tunable Bandpass Filter for the 40 60 GHz Region IEEE MTT S Inter national Microwave Symposium Digest 1985 pp 229 232 5 D Nicholson Ferrite Tuned Millimeter Wave Bandpass Fil ters With High Off Resonance Isolation IEEE MTT S Interna tional Microwave Symposium Digest 1988 pp 867 870 58 HEWLETT PACKARD JOURNAL OCTOBER 1990 Copr 1949 1998 Hewlett Packard Co Hexagonal Ferrites for Millimeter Wave Applications Scandium doped M phase barium ferrite has the necessary properties Crystals are grown and spheres are processed and tested in house by Dean B Nicholson errite spheres are commonly used as resonator ele F ments in magnetically tunable bandpass filters At frequencies below approximately 30 GHz yttrium iron garnet spheres abbreviated YIG chemical formula YsFe O are used extensively in this role At frequencies above about 30 GHz the millimeter wave region problems become apparent with the magnetic components used to tune the YIG spheres These problems include electromag net heating tuning nonlinearities and hysteresis The tuning equation of a YIG sphere applicable with H parallel to H is
193. rtunately because of the tighter sphere to sphere coupling the filter skirts were wider and the image rejection was degraded Filter Drive Circuitry For proper system operation the barium ferrite filter must track the input frequency of the spectrum analyzer The HP 11974 Series preselected mixer receives a tune ramp voltage from the spectrum analyzer that is propor tional to the frequency of the spectrum analyzer s first local oscillator For any given band assuming a certain harmonic number mixing sense and mixer IF this voltage is suffi Ref 0 0 dB 10 0 dB Sz dB 50 75 Frequency GHz Fig 12 Four sphere filter response with cavity mode sup pression 54 HEWLETT PACKARD JOURNAL OCTOBER 1990 cient to determine the millimeter wave frequency to which the spectrum analyzer is tuned This voltage is then con verted to a coil current that will tune the filter to the appro priate frequency To provide the correct current to the filter the frequency versus coil current characteristics of the filter must be taken into account The frequency of the barium ferrite filters varies linearly with current and a straight line approxima tion is sufficient For example a V band filter typically deviates from a straight line tuning equation by no more than 90 MHz over the entire range from 50 to 75 GHz Small tuning nonlinearities are compensated by using the preselector peak function of the spectrum analyzer This
194. s dials buttons and other physical and visual objects A command line interface is a totally foreign approach for these people and many of them refuse to deal with it Whatever can be done to enable the interfaces to come closer to the users current way of doing things is seen as having value A graphical user interface is seen as having the greatest potential in making the interface familiar Re cent developments in user interface technologies are very suitable for graphical user interfaces in industrial automa tion applications A MONG THE PRESENT and potential customers for Background HP IVIBuild is a tool that enables users to develop graphi cal user interfaces interactively Therefore it seemed appropriate that it should have a graphical user interface For this capability the HP IVIBuild developers decided to use the graphical user interface components that were under developmentat HP s Interface Technology Operation ITO in Corvallis Oregon These components are com monly called widgets They include things like menus scrollbars pushbuttons text edit boxes and radio buttons They are the raw materials from which a graphical user interface is assembled The HP IVIBuild team had no idea that using widgets would lead to collaborating with visual design professionals Neither did we the visual design professionals know about the HP IVI team We are the usability design and engineering group of HP s Software En
195. s and some of the boards were modified so that the hot wire could be inserted into the cabinet at the desired locations Velocity profiles were Copr 1949 1998 Hewlett Packard Co 30 Air Velocity m s E Experimental Computational Results Results Fig 7 Computed and experimental air velocities in CPU board slot 0 at the middle of the board measured in the CPU and I O board region across the boards A typical velocity profile measured in CPU board slot 0 at the middle of the board is shown in Fig 7 The slot depth X in Fig 3 is plotted on the x axis while the respective velocities are shown on the y axis It can be seen that the air velocities are in the range of 1 25 m s to 2 25 m s The velocities are about 1 5 m s at both ends of the board with the highest velocities of about 2 25 m s in the middle of the board One of the reasons for the nonunifor mity in the velocity profile is the presence of various com ponents chips heat sinks etc on the board A comparison of the numerical results with the experi mental results is also shown in Fig 7 The numerical results predict higher velocities in the center and lower velocities near the ends than were actually measured However the range of velocities is about 1 5 m s to 2 75 m s which is relatively close to that measured experimentally It should be noted that in the numerical simulations the board com ponents were modeled as blockage to the flow whereas in
196. s require graphical user interfaces and the use of graphics on the factory floor is growing and being applied to monitoring production processes and data gathering The requirements are performance reliability and the in tegrity of data from a workcell To satisfy these demands the HP IVI product Minimizes the user s expense for the development of user interfaces Provides a distributable user interface for improved cost performance and flexibility Offers windowing functions and dynamic data config uration Integrates graphics and widgets intelligently Gives software engineers the productivity boost needed for them to remain competitive Ensures top performance and reliability Gives the user full control over data from the factory floor Builds on standards Early in the project the HP IVI project team used a technique called quality function deployment QFD to help analyze customer needs in the industrial automation area This research helped to define the features for HP IVI The box on page 9 provides more information about QFD and its use by the HP IVI team HP IVIBuild HP IVIBuild is the interactive window and symbol build continued on page 8 HP IVI Build User Interface Objects Windows Symbols etc Functions Objects Created by HP IVI Application User Code API Application Program Interface Fig 1 HP IVIBuild is used to create user interface objects that
197. same process for the second model modet2id ZtCione is used with the function Arglist containing the ZIRECURSIVE attribute set to TRUE The call ZtChange changes the colors intret val Zild modeltid model2ld objectArglistforcolors static ZtArgListitem colorArglist ZIBACKGROUND COLOR ZtValueType red ZIFOREGROUNDCOLOR ZtValueType black NULL ZtValueType NULL k functionArglist for recursive attribute static ZtArgListitem recursiveArglist P ZIRECURSIVE ZtValueType TRUE NULL ZtValueType NULL model2id ZtClone modeltid NULL recursiveArglist ret val ZiChange model2ld colorArglist recursiveArglist Cloning nonrecursively ZtRECURSIVE FALSE can be used in cases where objects need to be referenced but copies of these objects are not needed Fig 4 shows the data struc ture that would result after nonrecursively cloning the ob jects referenced by the linked list called List Instead of copying the objects a new linked list List2 of pointers is created for referencing the objects The original and newly cloned list will dereference the same objects HP IVIBuild the builder component of HP IVI makes use of this option of 21 to duplicate lists of selected objects The cloned lists are manipulated through the use of list functions to provide the undo and backup capabilities of HPIVIBuild see page 36 When an object is no longer needed the function ZtFree can be used to free all me
198. sed as new boundary conditions for the next computation 5 This procedure was repeated until the guessed flow rate produced the corresponding pressure drop according to the fan curves Computations The three dimensional Navier Stokes equations of mo tion were solved in the nondimensional form The solution technique used was the segregated method A separate linear system was solved for each of the four degrees of freedom three velocity components and pressure Relaxa tion factors used for the four degrees of freedom were 0 8 0 8 0 8 for the three velocity components and 0 0 for pres sure To improve the accuracy and stability of the solution an upwinding factor of 1 0 was used for all degrees of freedom for all computations because high velocity gra dients were expected in the coarse mesh regions Starting from an initial linear Stokes flow solution the problem was run for five iterations using the segregated solver resulting in the following solution or convergence errors for the four degrees of freedom XVelocity 0 0084 m YVelocity 0 0074 m ZVelocity 0 0038 m Pressure 0 021 The FIDAP User s Manual recommends that these values be driven to 0 001 when using the segregated solver How ever we were not able to converge to values lower than these even though several other values of relaxation and upwinding parameters were tried After the initial five iteration solution a new fan flow rate was guessed and a secon
199. sent to ZtChange For instance if at some point in the program it is desired to have all the windows have a red background instead of the default blue a call could be made to ZtChange with the object type set to ZIWINDOW OBJ instead of the objectld Information about the current value of an object s attri butes or the default values can be obtained by making use of the ZtQuery call If required API will handle the space allocation for the queried values The following code frag ment is requesting information on a pushbutton object int return_val char querystr arglist for querying string static ZtArgListitem qstringArglist 1 ZILABEL STRING NULL ZiValueType NULL ZiValueType NULL Acopyofthepushbuttonid s label string will be returned in querystr f ZtQuery call A return value of FALSE indicates that I memorycouldnotbe allocated or an invalid pointer is specified in pushbuttonld I retum val ZtQuery pushbuttonid qstringArglist NULL querystr char qstringArglist 0 ZtValue the following callfrees the memory allocated for ZLABEL_STRING inthe ZtQuery call ZiFreeArgList astringArglist Save and Retrieve Objects The ZtSave function allows users to save objects in a file ANE NN List 2 Fig 4 Cloning lists of objects nonrecursively OCTOBER 1990 HEWLETT PACKARD JOURNAL 15 Copr 1949 1998 Hewlett Packard Co A filename can be spec
200. sess i EET ANTI HEWLETT PACKARD JOURNAL Articles An Overview of the HP Interactive Visual Interface by Roger K Lau and Mark E Thompson 7 HP IVI Project Management 9 Quality Function Deployment and HP IVI 1 1 The HP IVI Object Oriented Toolkit by Mydung Thi Tran and David G Wathen 2 Application Program Interface Design by Pamela W Munsch Warren Otsuka and Gary D Thomsen 29 Object Oriented Design in HP IVI 3 HP IVIBuild Interactive User Interface Builder for HP IVI by Steven P Witten and Hai Wen L Bienz 39 Creating an Effective User Interface for HP IVIBuild by Steven R Anderson and Jennifer Chaffee 4 26 5 to 75 GHz Preselected Mixers Based on Magnetically Tunable Barium Ferrite Filters by Dean B Nicholson Robert J Matreci and Michael J Levernier 59 Hexagonal Ferrites for Millimeter Wave Applications by Dean B Nicholson 6 HP DIS A Development Tool for Factory Floor Device Interfaces by Kent L Garliepp Irene Skupniewicz John U Frolich and Kathleen A Fulton 65 Finite State Machine 67 Matching Messages 69 Action Routines yapher Arvid A Danielson rative Services Diane W Wood 9 opean jon Supervisor Sonja With Editor Richard P Dolan Associ Support Supervisor Susan E Wright e Admi 2 HEWLETT PACKARD JOURNAL OCTOBER 1990 Hewiett Packard Company 1990 Printed in USA Copr 1949 1998 Hewlett Packard Co Research R
201. sing a com mand from a menu is often easier than remembering it The second fundamental principle is that making these choices by some means of direct manipulation is often preferred over typing in text commands Pushing a button or dragging a file icon into a folder icon or a trash can are two examples of direct manipulation Finally the third principle is to use metaphors from the real world For exam ple we know what to do with a pushbutton In our analyses of the many graphical interfaces existing today one of the impressions we formed was how confus ing they could be because of the flat and bland graphics This is especially true in multiwindow environments in which there is a high degree of overlapping and the simi larity of the graphic images seems to blend all the images together into one confusing mass We thought that creating OCTOBER 1990 HEWLETT PACKARD JOURNAL 39 Copr 1949 1998 Hewlett Packard Co greater visual distinctiveness between objects would signif icantly enhance a user s ability to keep things sorted out 3D Appearance of Widgets Our first attempts to express widgets graphically were with the traditional black lines on a white background To get away from the sameness mentioned above some of the widgets were drawn to look three dimensional and to look and act like pushbuttons It soon became apparent that the displays of the future would not be constrained to simple black and white and that larger areas
202. sity with a BSEE degree in 1984 He received an MBA degree in 1990 from the University of Denver A member of the IEEE he has coauthored two technical papers on packag ing Born in Lahore Pakistan Asad is married and lives in Fort Collins Colorado He enjoys squash bicycling and windsurfing Ravi Kaw developed a methodology to measure R L and C parameters in VLSI packages using coax ial probes rather than cus tom designed boards Since joining HP in 1982 he has served as a product engineer for DRAM and TOI math chips and as a semiconductor process engineer and has worked on package measurements and modeling re search Before joining HP Ravi was a lecturer at Kashmir University and an engineer at the Jet Pro pulsion Laboratories and Fairchild Semiconductor Corp He is the author of 14 technical articles on device physics device modeling packages and Copr 1949 1998 Hewlett Packard Co OCTOBER 1990 HEWLETT PACKARD JOURNAL 47 systems and measurement methods His work has resulted in two pending patents on packaging structures and systems and measurement methods Raviisa memberof the IEEE and the International Packaging Society He received his BE degree in 1966 in electronics and telecommunications from Jabalpur University his MSEE degree in 1972 in microwave solid state devices trom Marquette Uni versity and his PhD degree in 1978 in solid state electronics quantum electronics and microwaves fro
203. son Visual interface designer Steve Anderson helped de 8 7 the HP IViBuild product He joined HP s Calculator Products Division in 1976 and was responsible forthe industrial design package for the HP 9845 computer controller and computer system furniture products including the HP 92214 CAD worktable Now a lead designer on the HP VUE graphical environment for HP UX worksta tions Steve s professional interests include making computers visually appealing and fun to use He is named as an inventor on an industrial design patent for a Xerox copier coinventor of a product design layout patent on a color printer concept trom HP Laboratories and coinventor on a patent application for HP 3D widgets and extensions Steve received a BS degree in industrial design from the University of Bridgeport in 1966 Born in Hibbing Minnesota he is married has two chil dren and lives in Mountain View California He en joys playing golf at dawn on Sundays bicycling to work and activities with his children Jennifer Chaffee worked on the user interface for the HP IViBuild product at HP s Industrial Applications Center She joined HP in 1988 and worked on HP OSF Motif and the HP N Wave Office Before ing to HP she worked inthe a industrial design and user interlace department of the Xerox Corporation copier division A 1985 graduate of the Rochester Institute of Technology with a BFA degree in graphic design and art history
204. t Message to the Current State Continue Looking for Events Fig 6 The state transition process OCTOBER 1990 HEWLETT PACKARD JOURNAL 35 1949 1998 Hewlett Packard Co places the new pointer at the top of the state stack making the state current and sends a start message to the new state Thus by inheritance every state object has the ability to activate any other state object When an intrastate transition occurs there is no change to the current state i e the pointers are equal The current state handles the incoming message itself State Protocol All states follow a specific protocol that is implemented in the state machine of HP IVIBuild Fig 7 illustrates this protocol An interstate transition Fig 7a occurs when the current state receives an exit message and it returns a NULL to the state machine indicating that it wants to cease being the current state The state machine makes the new state the current state and sends a start message to the new state The new state remains the current state as long as it con tinues to return a pointer to itself to the state machine e g Current State in Fig 7b Following this protocol allows a state to control the meaning of user input within its own context Each state implements or inherits five standard methods that constitute its operational interface start hit backup undo and exit Start As shown in Fig 7 the start message is the first message
205. t results in a call to a function to find the object that is under the point The function will search the hierar chy for an object that has the point in its extent If a graphic object is found the object list is searched to see if there is corresponding callback function and if so the event is dispatched to the function Global Callbacks A requirement of the API was to detect a function key press regardless of the location of the sprite in the window This was a problem if the sprite was over a widget when a function key was pressed because widgets grab any input over them The project team extended the callback process so that the window object could also receive the event even if it was over a widget This type of callback is referred to as a global callback Global callbacks are implemented by providing an addi tional check during the input processing in the server object see Fig 5 After the event is dispatched to the appropriate object a check is made to see if global callbacks are enabled Callback Object 1 E 4 Widget d or API Object 7 1 i Reason for Callback Integer Value Representing Type ot Callback Callback Specific Data e g File Descriptors Fig 6 A callback object in the API 24 HEWLETT PACKARD JOURNAL OCTOBER 1990 If so the event is dispatched again to the window object and any global callbacks attached to the window that match the event are called For events that were origi
206. tch objects that have certain properties For example if an application creates a large number of objects and some of them are invisible to find all the invisible objects the ZtFindByAttribute function is used on the window object passing an object Arglist with the ZtVISIBLE attribute set to FALSE Receive Input Functions Input events like button and key presses can be collected using the function ZtDo Objectld ZINPUT NULL Where object ld is the Ztld of a system object and ZtINPUT is the action for ZtDo to do The input handling ZtDo function retrieves the events and dispatches them to the appropriate callback function so that the user defined action can be executed User input can be collected continuously or in a single pass Visual Update Functions In addition to getting input ZtDo provides several other actions It provides the capabilities to update draw re draw flash erase raise and lower objects on the display The following is a list of the different operations possible with the ZtDo function 16 HEWLETT PACKARD JOURNAL OCTOBER 1990 redrawallobjects whether or notthey have been modified ZtDo systemid ZIREDRAW NULL drawawindow ZiDo windowld ZIUPDATE NULL flashan objecton the display ZiDo pushbuttonid ZtFLASH NULL flashtheobjectsona list ZtDo listld ZIFLASH NULL erasearectangle object ZtDo rectangleld ZIERASE NULL erasealistof objects ZiDo listld ZtERASE NU
207. thatcauses transition to this state groupmembership Pointertogroupmembership information y k idState s rect idState amp state rect A polntertothisstate thatisusedby HP IVIBuild toaccessand manipulate data this structure bi Inheritance In HP IVIBuild as in most object oriented systems state objects are arranged in a hierarchy At the root of the hierarchy is a special state known as the root state see Fig 4 The root state in HP IVIBuild manages interstate transitions Since the root state is at the top of the object hierarchy it implements many more methods than the other states in HP IVIBuild Using inheritance the lower level objects inherit all the methods from the root state This inheritance mechanism is used to imple Fig 4 A portion of the HP IVIBuild object hierarchy 34 HEWLETT PACKARD JOURNAL OCTOBER 1990 ment state transitions in HP IVIBuild Polymorphism HP IVIBuild s central input handling facil ity which is called the state machine depends on the concept of polymorphism All states in HP IVIBuild have the same operational interface i e the state object is polymorphic Therefore to the state machine all states look the same and are able to respond to the same set of messages The state machine does not know or care which state is currently active It only knows that the current state either implements or inherits all the methods that are the
208. the same angle as the actual vanes Although the computational effort required to generate this three dimensional model was moderate it took ap proximately 1 4 engineer months to create the model be ginning from mechanical drawings It is also important to note that the use of computer graphics was essential to the successful creation of this mesh visual analysis of the mesh COMPUTER AIRFLOW AT ASSEMBLY LEVEL CRAY SIMULATION EY VECTOR PLOT SCALE FACTOR 0 1000 03 VECTOR PLOTTED 0 2831E 01 AT NODE 61143 A 0 100 01 B 0 000 00 C 0 000E 00 VIEW DIRECTION VX 100 01 vy 9 30000 VZ 0 B00E 01 ANG 100E 03 Fig 4 Computed flow velocities the 2 plane through the 17 40 56 84 HEWLETI PACKARD JOURNAL OCTOBER 1990 printed circuit boards Copr 1949 1998 Hewlett Packard Co Fig 5 generator s results being the only good means of checking Boundary Conditions progress For this both FIDAP s postprocessor FDPOST The physical probler and Cray s Multi Purpose Graphics teady jus laminar isoth was three d nal flow Because the ve of the order of 2 m s and all the flow assumed to be through the used All computations includ formed on CRAY Y MP of the compo to be laminar The flow length s 1 ermal because the main focus of the problem was the 85 Copr 1949
209. the state diagram A state table uses one row for each state and one column for each input In each box are written the next state and the output The first row of the state table is usually assigned to the initial state of the machine Astate diagramis a directed graph in which each arc is labeled with the input that causes the transition and the output that is generated when the transition is triggered A classic example is a parity checker This machine takes an input stream of bits of ones and zeros For each input bit the machine produces an output indicating whether the entire input sequence so far has even or odd parity The state table and diagram are shown in Fig 1 The HP DIS state table written in PSL is shown below The initial or home state is have even When an event is triggered by the receipt of a 0 or 1 the protocol interface prints a message using the user action routine called Ut Events zero_recd response 0 response 1 States have even State Table have_even zero recd Ut print even have even have even one recd print odd have odd have odd zero recd U1 print odd have odd have odd recd Ut print even have even State Table zero recd one have even have even print even have odd print odd have odd have odd print odd have even print even Fig 1 State table and
210. ther inter face the state operations result in a rectangle The binding of functionality to user interface presenta tion is done when HP IVIBuild starts up At this time the objects windows menus buttons etc that make up the HP IVIBuild user interface are restored from a file Pointers to objects Ztlds that activate states or send messages to the state machine are looked up using the name of the object that was assigned when the object was created with the API functions This lookup is accomplished using an API function When the Ztld for an object is returned the mes sage selector for the state to be activated is retrieved At this point a callback object ZtICALLBACK OBJ which will call the state machine whenever an event occurs on the user interface object is created for the user interface object Also the message selector from the state object is made an attribute ZIUSER DATA of the user interface object Once the callback object is attached to the user interface object the binding is complete see Fig 10 When a specified event occurs on a particular user interface object the in terstate transitions described earlier occur This scheme makes the state machine a callback for every IVIBuild user interface object and for every workspace window the user creates Separating the user interface presentation from function ality means that the presentation can be developed inde pendent of functionality and the same functionali
211. time consuming and marginally successful Good documentation of existing software is essential for a product to be successful Inadequate or inaccurate documen tation can also impact schedules t is very important to establish a good line of communication and a strong working relationship with the existing software supplier Changes made to their product may have drastic effects on the local product It is important to learn about changes as early as possible i e at the investigation phase rather than at the release phase Project teams that leverage a large amount of software from other sources should be very careful not to assume that leverag ing means that less attention can be paid to producing a very detailed design Leveraging software does not mean there is no cost associated with it Engineers have to learn and understand the code design impacts must be assessed and the leveraged code must be supported over the life of the product Also leveraging product components does not automatically ensure a faster time to market New Technologies HP IVI is an object oriented system that is based on the widget technologies and the X Window System Through the QFD pro cess we found that building on a standard software platform is viewed as an important requirement by our target market At the start of the HP IVI project no one on the team had any experience with object oriented programming and design and only one person was famil
212. tion because they have little or no coverage This task is the most labor intensive portion of the QFD process To get the features for the first and second release of HP IVI from the matrix we assigned a number to each cell For each feature we summed the cells to get an idea of how effective the feature would be at meeting the customer needs We selected a cutoff value to determine the set of features that would bring us the most return for our investment in engineering time and effort proved to be an excellent tool for product definition The feature set that was established for HP IVI has generated much customer interest One of the most significant benefits from this Primary Secondary Tertiary Screens Come up 2to3 Fast Seconds Must Have Good r ex Pictures not Text Icons Must Have Range Forms Entry Checking for Needed Data Entry Fig 2 A sample of customer needs and wants murmurs ranked in primary secondary and tertiary order OCTOBER 1990 HEWLETT PACKARD JOURNAL 9 Copr 1949 1998 Hewlett Packard Co in the investigation phase helps keep the analysis from bogging down in too much detail Also needed are tools to support the technique The HP IVI team did most of the data analysis manually Display Hardware Software sis 5 5 gjg HE Implementation 2 2 E Method s s 8 l 2 9 2 2 EIE
213. ts provided both behavioral benefits text properly centered Dw 42 HEWLETT PACKARD Copr 1949 1998 Hewlett Packard Co in widgets text baselines lined up etc and a consistent high quality look The designers also created all of the bit maps and icons associated with the tool boxes and other aspects of the product One challenge with many of the tool box buttons especially for those in the widgets mode was to express the 3D nature on a small scale and with only two colors The illusion of using three colors was achieved by using a light and a dark color and then introducing a dithered ls together to form a third color pattern that the eye ble see Fig 6 The final area of collaboration was to do something visual and graphical to help explain and sell HP IVIBuild Some sample screens were created that express how HP IVIBuild can actually be used With just a little prompting on how Models Widgets to use the 3D effect a designer used HP IVIBuild to create two sample screens for each of seven potential application reas These compelling images achieved through the use of the actual tool have done more to explain HP IVIBuild and its capabilities than a volume of marketing brochures One of these sample screens is shown in Fig 2 on page 8 Conclusion We learned a few things as a result of this collaborative exercise One is that experts often have problems com municating their concepts and ideas to non
214. tween the operation of the widgets and the graphic and window objects the coordinate system feature of the API 30 HEWLETT PACKARD JOURNAL OCTOBER 1990 still provides a large productivity gain for the application developer 1949 1998 Hewlett Packard Co Object Oriented Architecture Without usingan object oriented programming language the API encompasses features provided by an object oriented language through conventional C language fea tures The API s architecture is divided into three layers the API function layer the API object layer and the device dependent layer see Fig 12 The API function layer pro vides the communication interface between a user applica tion and the objects created by the application It is a thin layer of code that validates the user s parameters and sends messages to the objects to perform the tasks requested The functions provided in this layer are described in the article on page 11 In the API object layer an object is created and destroyed and all manipulation of an object s data occurs In the device dependent layer all the function calls to underlying subsystems are made to draw an object to the display Messaging in the API The API consists of a number of function calls that pro vide the communication path between an application and the underlying objects manipulated by the application Most of the API functions require objects as parameters It is through this interface th
215. ty can be easily given a new presentation New functionality can be added and tested in a straightforward way without worry ing about its presentation Conclusion HP IVIBuild was conceived with two objectives in mind to be a powerful easy to use tool to complement the HP IVI application program interface functions and to be the first API application and as such to provide feedback to the API development team Both of these objectives have been accomplished We believe that HP IVIBuild s func tionality and designed in extensibility based on an object oriented architecture are among the first for tools of this type 38 HEWLETT PACKARD JOURNAL OCTOBER 1990 Acknowledgments There were many challenges presented and many re wards gained in the development of HP IVIBuild So many people added their inputs to HP IVIBuild that it is hard to mention them all We would however like to thank Ron MacDonald now at HP s Graphics Technology Division in Fort Collins Colorado who endured a year away from his home to work on HP IVIBuild Every time a user draws a polyline or spline or makes a widget with HP IVIBuild they will be using Ron s work Thanks also go to Shiz Kobara of HP s Software Engineering Systems Division SESD who had the original idea that the user interface was a place where industrial designers could make a con tribution Thanks to Steve Anderson and Jennifer Chaffee of SESD who followed through on Shiz s idea while Shiz was
216. uction data for six months shows a distribution with a mean of 1 43 and a standard deviation of 0 034 Fig 4 The measured data projects a specification of 1 33 to 1 53 The simulated and manufacturing statistics are compared in Table I Statistical Simulation as a Diagnostic Tool A second example of the power of this simulation technique illustrates its role as a diagnostic tool The por tion of the IC under study is the dc restore circuit which level shifts the complementary high frequency outputs to the ground level A block diagram is shown in Fig 5 From 600 140 145 4 160 Minimum Amplifier Gain Fig 4 Six month production data has a distribution with a mean of 1 43 and a standard deviation of 0 034 The minimum gain specification is 1 33 to 1 53 80 HEWLETT PACKARD JOURNAL OCTOBER 1990 Vee High Frequency b High Frequency Inverting 4 gt Noninverting Output Output 2R 2R R Level Shifted Output Operational Amplifier Fig 5 A portion of the integrated amplifier IC showing the operational amplifier and resistor bridge of the level shifting subcircuit The op amp in this dc restore circuit had a large low frequency output offset for which the simulation data did not match the production data suggesting a process anomaly Table 1 Comparison of Simulated and Measured Minimum Gain Distributions Simulated Measured Mean 1 44 1 43 Standard Deviation 0 04 0 034 Specification 1 33
217. ugh the boards and the system pressure drop have reasonably good accu racy Project Objective For the thermal management of air cooled computers the key air flow parameters to be determined are the air Top View r 65 r 70 cm Fan Tray Fan Tray Side View Front View Fig 1 HP 9000 Model 850 computer system processing unit right side of computer in photo There are six fans 82 HEWLETT PACKARD JOURNAL OCTOBER 1990 Copr 1949 1998 Hewlett Packard Co velocities in the computer cabine the pressure dror the syst el lesigning s t within computer cat t riment sured on prototypes of the machines Unfortuna accurate prototype can only be available whe i ponents of a system have been designed This t happens only towards the end of a the flow characteristics and the system pressure drop c ost all the compo be accurately measured only after nents of the system have already been designed If for some reason the pressure drop is found to be excessive or the air flow characteristics are found to be different than ex ign changes may have to be made at the pected major de end of the design cycle resulting in serious product mod ifications and delays Furthermore experimental measure ments in a prototype are both difficult and expensive in terms of human effort It would be advantageous to have modeling tools that can predict these air flow char
218. unctions HP IVIBuild provides the following advantag over this method No initial prog imming is required The user can look at the user interface and manipulate it while creating it m The interface can be altered very quickly Several graphical conveniences are available such as snappingtoa grid and a simple method of creating ellipses An API program that uses HP IVIBuild created objects is much simpler than one that creates the same objects from scratch Symbols created in an HP IVIBuild session can be saved and reused The articles on pages 32 and 39 provide more information about HP IVIBuild Objects and API Since HP IVI is an object oriented sys are done with objects resulting in a system that is a hierar chy of objects Building this hierarchy starts with creating m all operations 8 HEWLETT PACKAI window objects windows on the display and then placing graphics and widget objects into the windows To activate the objects in the window i e give them dynamic proper ties some of the attributes of the objects can be changed foreground or background color visibility or fill per centage for a rectangle When an application uses objects to display data values it can make calls to the API functions to update the data values in the objects displayed in the windows The objects used in HP IVI are categorized into four hierarchical layers High Level Objects These objects spe
219. ure contains a variable the data from the message is placed into the structure according to the length of the variable Byte and Boolean variables are one byte long Integer variables are two bytes long and real and long variables are four bytes long String variables can be NULL or up to 4K bytes long Data from the message is parsed into the structure s fields according to the variable lengths Constants and literals are matched exactly The lengths of data types are the same as above but the message data must contain the bit pattern that matches the constant Constants or literals adjacent to string variables are used for delimiting the strings The HP DIS compiler builds a table for each structure describ ing data in each field The matching process then walks this table for each structure If there are no string variables in a structure then each byte is easily assigned to a structure field There is no ambiguity However if there are any string variables inthe structure then ambiguity branching begins because string variables can be NULL or up to 4K bytes long The matching process branches assigning this byte to both the string variable Matching Messages and to the next field This ambiguity is resolved either by the next constant or by the end of the message HP DIS makes the first shortest match unlike the HP UX editor vi which makes a first longest match For example the fields in a structure are variable string str1
220. w ing code fragments demonstrate using these functions Figs 7a and 7b show the results of the ZtinsertListindex and the ZtinsertListObject examples respectively insert an object at location two in list pointListId Ztld pointListld pointtld newpointListld insertpointld refpointld pointid int ret pointListld the Ztld of a ZILIST OBJ to insert the object into pointtld the Ztld of the object to insert into the list newpointListld the 209 of the new list If the function r fails the original pointListld is returned r in newpointListld If the function succeeds r the new list is returned in newpointListid objlndex ret ZtinsertListindex pointListld objindex pointtld amp newpointListld insert an object insertpointld into list pointListid in tront of another object refpointid s ret ZtinsertListObject pointListld relpointld insertpointid amp newpointListld add a point object pointld to the end of a point list pointListld af ret ZtinsertListTail pointListld pointld amp newpointListld Merging Lists A list of objects can be merged into another pointtid point2ld T Hi Fig 6 Data organization illustrating a list of two points created with the function ZiCreateList OCTOBER 1990 HEWLETT PACKARD JOURNAL 17 Copr 1949 1998 Hewlett Packard Co list by using m ZtMergeListindex to place the list at a specifi
221. where he enjoys Tae Kwon Do skiing 4 wheel driving backpacking and traveling 21 HP IVI API Design Pamela W Munsch Pam Munsch a software development engineer on the HP IVI project at HP s industrial Applications Center worked as a de velopment engineer on an IC testing project shortly after she joined HP s Santa lara Division in 1983 She isnowan R amp D project man Copr 1949 1998 Hewlett Packard Co OCTOBER 1990 HEWLETT PACKARD JOURNAL 45 ager working on HP IVI Pam received her BS de gree in computer science in 1983 from the Univer sity ol California at Santa Barbara She is married lives in the city of her birth San Jose California and enjoys playing volleyball Warren Otsuka As an R amp D software en gineer at HP s Industrial Applications Center Warren Otsuka was responsible for input handling and widget ob jects for the HP IVI project Alter joining HP s Data Sys ANM Division in 1978 he W worked on support for the HP F 1000 forms management tool and HP F 1000 HP UX products Before joining HP Warren was a project lead for user interface development and an engineer on a document project for raphix Inc and he provided system support for the STAR 100 operating system at Control Data Corporation He eared a BS degree in computer science from the California State University at Chicoin 1972 Born in Kona Hawaii Warren is ried has a daughter and
222. y attached to the HP 11974 for reference Acknowledgments R amp D team member Dick Beardsley designed all the crit ical mechanical parts and made them look simple He also organized the R amp D retreats at the salmon school locations off the Northern California coast The product introduction team completed their work in record time and included Robert Charlton George Zimenski Ron Flatt Mariko Hoy Lonnie White Jim Lusk Tom Berto Joe Wax Rich Pope Bob Fullmer Dennis DeMaria Rebbie Toledo Karen Bigham Mike Picha Bernie Hoven Joyce Wong Dennie Yamaoko and Kathy Sparks Mike Dethlefsen Ernie de Martini Mike Brown and Steve Flint designed the retrofit kits vital to the project Marketing efforts were by Eric Brown and Dennis Handlon Important early development work on the filter and test routines was performed by Jim mie Yarnel Dennis Derickson Matt Fowler and Hiroshi Imiazumi Summer intern Davie Zoneraich built the first version of the millimeter tracking generator test set Our lab section management Frank Angelo and Toni Coon endured endless project reviews and kept us inspired And then there is Frank David who peeled the company s first layer from the millimeter onion a decade ago References 1 R A Shaffer Promising Uses are Emerging for Millimeter Radio Signals The Wall Street Journal June 26 1981 pg 29 2 R J Matreci and F K David Unbiased Subharmonic Mixers for Millimeter Wave Spectrum Analyze
223. z s HAE t f 5 5 8 z a amp lz SB z x amp x E Primary Secondary Tertiary Screens Must Have up A Good Fast Performance Many Symbos 10922 Screen Must Have Pictures Good Icons o o A Ergonomics 9 Text 949199 Sio Must Have Range Forms Enty Checking o oo for Data Entry Xe L Strong Relationship Medium Relationship Fig 3 Portion of a relationship Small Relationship matrix process was that because the engineering team was involved and as a consequence the data has not been updated as often in this process th y emerged with a much better understanding as might have been done if the data could be manipulated elec of what the users really wanted tronically Knowing when to stop the QFD analysis is important Unless specific goals and targets are set overanalyzing can waste valu able project time Establishing a set of musts and wants to be Mark Thompson accomplished with QFD and drawing clear boundary lines early Kent Chao Software Development Engineers Industrial Application Center jects Composite objects can be used to organize and add extra control over their descendant objects For example a row column object can be used to organize different widget primitives into rows and columns All objects in the hierarchy have attributes e g color size shading etc It is through th

1990 , Volume , Issue Oct-1990

Contents

Download Pdf Manuals

Related Search

Related Contents