Instructions For Use of PCI Extender Cards (EV9323A)
Contents
1. Instructions For Use of PCI Extender Cards EV9323A Revision 1 3 Table of Contents 1 Specifications 2 Extender Card Features 3 Applications 3 1 Timing Analysis and Probing 3 2 Logic Analyzer Triggering 3 3 Current Consumption Measurements 3 4 Supply Voltage Variation 3 5 Experimentation and Prototyping 3 6 Debugging Hardware Problems 3 7 Slot Wearout Prevention 3 8 Environmental Testing 3 9 Miscellaneous Uses Copyright 2003 Barry L Kramer 1 Specifications The extender card is a tool for engineering analysis experimentation and hardware design qualification It is designed to generally conform to PCI 2 1 specification mechanically and to produce as little electrical signal degradation as possible while still performing its function Refer to the provided schematics drawings and user manual for complete details and specifications 2 Extender Card Features All PCI signals are routed through the card with most bus control signals able to be disconnected with the installed individual signal isolation switches Weak 10K pullups are provided for the PCI control signals FRAME STOP IRDY TRDY DEVSEL RESET and CLK so that they are deasserted on the extender card s top receptacle if the signals are disconnected from the bus with the switches The peripheral under test can be hard reset by opening the switch and grounding its RESET input accessible at the RESET switch Weak 10K pulldown is provided on the ID2. SEL signal so it is deasserted when disconnected Test pin dimension and spacing accommodate all standard logic analyzer probes Plenty of ground points are provided for grounding logic analyzer pods and scope probes Signals are clearly labeled on the silkscreen on both sides of the board Extender cards can be stuffed with components on the A side or the B side so that test points are oriented outward regardless of physical constraints of motherboard component orientation or arrangement of other installed peripheral cards 20 pin sockets connected to 5V pin 20 and GND pin 10 are provided for prototyping such as with 16V8 GALs or other logic Fuses are installed on the 3V and 5V supply rails for isolation testing and to help prevent accidental shorts from causing board or component damage Test points are provided for easy access to drive the peripheral under test with external supplies with the fuse removed Components on the card are not sensitive to ESD 3 Applications 3 1 Timing Analysis and Probing Your extender card can be used to perform certain types of timing analysis and measurements on PCI signals by attaching an oscilloscope or logic analyzer to the exposed test points After connecting the probes to the correct location create or modify software to transition the output signals being measured With this technique it is possible to easily measure delay and setup and hold times It s very easy to change bo
3. and the motherboard using its supply approximately simultaneously to avoid component damage It is highly recommended to power them up then reset the motherboard with the hardware reset button even if it doesn t seem necessary to do so This will duplicate the condition of having the device installed in the motherboard slot and will insure the motherboard BIOS initializes the peripheral under test correctly After boot up measure the effect of varying the supply voltage and the corresponding current consumption if desired in the various states of operation such as in reset uninitialized initialized but not operating and operating This can be used to establish the operational supply voltage range and maximum power If the peripheral under test includes power supply regulation on the board it will be necessary to defeat it in order to get any useful results from this test 3 5 Experimentation and Prototyping Because the extender card features easy access to the PCI signals and provides sockets for programmable logic it is easy to prototype some very useful analytical circuits or make modifications to the bus signals such as might be necessary to correct PCI protocol violations on new chip or board designs 5V and GND and proper decoupling capacitors are provided for the 20 pin sockets which are ideally suited for Lattice GAL16V8 5LP or similar If you intend to create registered equations be sure to connect CLK to pin 1 and ground p
4. ards under test and because the test equipment is connected to the extender card rather than the board under test it takes very little time to measure differences in timing or delay across multiple boards Signals can also be easily multi probed with analog equipment or an oscilloscope module in a logic analyzer so that a normal logic analyzer display digital waveforms can be shown time correlated to the analog signal Set the analyzer to trigger on the logic condition and then trigger the other module A PCI interface card such as Future Plus Systems FS16P32E in another PCI slot is useful for this Shorted AD lines on a board needing repair can usually be quickly found by searching the labeled AD 31 0 test points with an oscilloscope and looking for degraded signal quality 3 2 Logic Analyzer Triggering The extender card can be used to trigger a logic analyzer at a specific location in software such as an application or device driver by a simple modification to the software and only a few test points This is very effective when most of the logic analyzer probes are consumed monitoring non PCI signals on the peripheral card and not available for a complex trigger or at any time that software is capable of detecting the anomaly either just before or just after it happens Simply connect FRAME CBE 3 0 and IDSEL to the logic analyzer set it to trigger on a configuration space read or write and modify the software to generate th
5. at access at the proper time If triggering is unreliable due to these patterns occurring in the data phases in the normal course of events modify the extender card to produce a delayed FRAME signal DFRAME by installing and programming a 16V8 in one of the provided prototype slots and include that signal in the trigger to differentiate the address phase from the data phase 3 3 Current Consumption Measurements Current consumption of a peripheral card can be easily measured by removing the 3 3V and or 5V supply fuses and substituting an ammeter By measuring the supply voltage on the provided test points board power consumption can be calculated The extender card rarely interferes with operation of the peripheral under test so these measurements can be taken under a variety of operating conditions and also quickly checked across multiple boards Exercise care in taking these measurements that you are in fact observing outputs from the device under test rather than outputs from another source such as motherboard when attempting to measure signals on a peripheral card Delay is the time from an input clock edge that causes a transition to the actual transition of a given output It is defined for output signals and is usually the only temporally oriented parameter for characterizing outputs Due to asymmetry in rising and falling signals it s typical to separately measure delay for clk for rising edge synchronous circuits to o
6. d general engineering debugging or analysis www adexelec com 3 8 Environmental Testing Because the extender card moves the peripheral under test physically away from the motherboard it is possible to construct a small environmental test chamber which encloses the peripheral card The enclosure can rest on the system case and then the peripheral card can be heated or cooled in the chamber without affecting the motherboard or other installed peripherals Sometimes two extender cards or a taller extender card must be used depending on the system case and the test chamber design This arrangement is particularly useful to establish the operational temperature range of a peripheral card as well as the effect of temperature on supply current or operating voltage range 3 9 Miscellaneous Uses Because the card provides easy access to power and ground prototype PCI cards can be placed in the extender card s top receptacle and quickly checked with a meter for supply shorts prior to installing the prototype cards in a motherboard The power points are well labeled and therefore usually easier to identify than probing the prototype card directly There are many circumstances where it might be desirable to isolate a PCI signal such as a peripheral card s INTA output from the motherboard by disconnecting it with the switch at the proper time while it is operating in the system While this often interferes with the system operation this sort of
7. experiment should work once and in many cases provides useful information such as to identify which PCI card in a system asserted a certain signal that s shared across multiple cards Disconnect the FRAME signal with the switch to make the peripheral card never respond to a PCI access until FRAME is reconnected Disconnect the RESET signal and ground the peripheral card s RESET input to hold it in reset Doing this in a temporary manner is very useful when writing diagnostic software which is capable of completely reinitializing the peripheral including the registers that are normally set only by the motherboard BIOS when the system boots up End
8. in 11 OE It is recommended to install a 20 pin socket on the component side of the extender card to accommodate the programmable logic By using this method and routing a few PCI control signals through the 16V8 it is possible to make many modifications to the signals generated by the peripheral under test or to the signals visible to the peripheral under test Useful modifications might include protocol corrections delaying some signals such as to test the effect of a slower DEVSEL timing or splitting shared signals from two cards to look at their behavior independently and recombining them so it looks identical to the motherboard and therefore not interfering with proper system operation 3 6 Debugging Hardware Problems The isolation switches on the extender card make it very easy to identify the specific location of connection faults on a peripheral card This is very useful if you put a peripheral you just built or modified into a motherboard and it doesn t boot There are typically only two tests to run 1 Isolate the FRAME signal by opening the switch If it boots now there probably aren t any shorted AD or control signals rather some other problem exists such as a protocol violation 2 Disconnect all the control signals from the bus by opening all the switches If it boots there is a good chance there is a short on the control signals Disconnect FRAME and binary search for the signal short If it doesn t boot
9. it s probably a short in the AD lines Unfortunately these can t be isolated so you probably need to perform a visual inspection after identifying which signals appear to be shorted as suggested earlier end of section 3 1 3 7 Slot Wearout Prevention When performing experiments and design qualifications with prototype cards there is usually a great deal of insertion and removal This can lead to destruction of the motherboard In cases where the motherboards are difficult to obtain or are very expensive slot wearout can be avoided by using the extender card If the extender card s top receptacle wears out it can be easily replaced If desired modify the extender card by installing a standard VGA connector on the board Then attach a PCI slot retaining bracket to the VGA connector A slot screw can then be used to secure the extender card into the computer case This doesn t work of course if you have an exposed motherboard not in a case Depending on the application an alternative board such as Adex Electronics PCIX32 Bus Isolation Extender may be preferred This card can completely isolate the upper receptacle including power and ground by one switch or control line This is very useful when testing many boards at a manufacturing facility where the time saved by swapping boards under test without rebooting the test station is important However the Adex cards are much less useful for hardware development design qualification an
10. utput T and also clk to output J Setup and hold are defined only for input signals this is the time before and after the input clock edge which latches the input to the most recent transition of the input being latched before or after the clock edge equivalently the time before and after the clock where the input is stable They are usually the only temporally oriented parameters for characterizing inputs Setup and hold should also be separately checked for both rising and falling input signal transitions In both cases it is vital to record the threshold voltage used to take the measurement FRAME 0 CBE 3 0 1010 read or 1011 write IDSEL 1 3 To measure current consumption when the device is uninitialized or in hardware reset simply open the RESET switch take the reset state measurement then close the switch and take the uninitialized measurement RESET is automatically asserted when the switch is open 3 4 Supply Voltage Variation Power supply voltage variation and resulting current consumption differences testing is a natural extension of the current consumption measurements suggested previously Instead of using an ammeter remove the fuse s and substitute adjustable power supplies connected at the test point Be sure to connect the power supply correctly so it sources the peripheral and not the motherboard Typically when doing this test it will be necessary to power up the device under test using the supply
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