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USER`S MANUAL

1. VCCLNA2 2 GND vecvco UAAIS70 Title GPS DEMO BOARD RF FRONT END Number Revision 801291_4 1 3 Figure 5 GPS Demo Board RF Front End 50 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 6 3 2 PCB Build of Materials Table 10 Build of Materials for Demonstration Board QTY Value Part Number Description 1 C321 0603 SM Capacitor NPO 1 C306 0603 SM Capacitor NPO 1 C326 0603 SM Capacitor NPO 1 1 5 pF 5 C324 0603 SM Capacitor NPO 6 100 nF C105 C106 C201 C202 0603 SM Capacitor X7R _ 204 C208 C327 C348 0603 SM Capacitor C340 0603 SM Capacitor NPO C338 0603 SM Capacitor NPO 18 pF C309 0603 SM Capacitor NPO C101 C102 C103 C104 0608 SM Capacitor X7R C311 C312 4 1 1 1 C322 C323 0603 SM Capacitor NPO C205 C206 C325 0603 SM Capacitor NPO 1 3 9 nF C341 0603 SM Capacitor X7R C210 C211 C212 C213 0603 SM Capacitor X7R C214 C215 C216 C217 C218 C219 C220 C221 C222 C223 C224 C328 C329 C330 C331 C332 C333 C334 C335 C336 C337 C346 2 C313 C314 0603 SM Capacitor NPO 1 19 0603 SM Capacitor 1 4 7 pF C339 0603 SM Capacitor NPO 2 4700 pF C342 C343 0603 SM Capacitor X7R 1 470 nF C112 1206 SM Capacitor X7R 2 47 pF C302 C303 0603
2. The TTFF varies depending on the completeness of the initialisation data Table 2 on Page 13 provides the TTFF specification for this system For information on aiding the initial acquisition process please refer to Section 5 4 on Page 41 which outlines the commands for entering the current time and estimated user position 15 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 3 3 3 Navigating This section outlines the different modes of operation when the system is generating a navigation solution The chip set and navigation software process the pseudorange data received from up to 8 satellites For the best navigation solution the set of satellites to be tracked are determined by examining satellite geometry 3 3 3 1 Mode 0 fixed 3D At least four satellites are required with elevation above the position elevation mask angle All three polar coordinates are computed in this mode there are fewer than four satellites or one of the DOPs exceeds its mask then no navigation solution shall be computed and an exception message shall indicate this 3 3 3 2 Mode 1 three satellite At least three satellites with elevation equal to or above the position elevation mask are needed to compute a position If 3 satellites are locked then the receiver operates as though it were in 2D mode If 4 or more satellites are locked the receiver operates as though it were in 3D
3. USER S MANUAL SNA UM98008 User Interface Manual for the EXACT GPS Chip Set Version 1 2 Philips PHILIPS Semiconductors Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 REVISION HISTORY Version Remarks 1 0 First release 1 1 User commands and descriptions updated Section 6 added outlining application details including schematic and a quick start up guide Section 7 added outlining the functionality of the PC support software for evaluating the EXACT demonstration system 1 2 Quick start guide has become independent section and now includes the setup for differential GPS position output Minor corrections made to user commands PHILS UDD and PHILQ RTC Alterations made to schematics and parts list to comply with current starter kit New Section 6 3 3 Board Costing Consiiderations added LIFE SUPPORT APPLICATIONS Philips Semiconductors and Philips Electronics North America Corporation Products are not designed for use in life support appliances devices or systems where malfunction of a Philips Semiconductors and Philips Electronics North America Corporation Product can reasonably be expected to result in a personal injury Philips Semiconductors and Philips Electronics North America Corporation customers using or selling Philips Semiconductors and Philips Electronics North America Corporation Products in such applications do so at
4. Sentence PHILR RID EX lt firmware gt Usage Returned in response to PHILQ RID Parameters parameter range meaning lt firmware gt Firmware revision code 4 characters Response For example response might be PHILR RID EX HCOO 4 1 7 10 Last exception message PHILR XMG Sentence PHILR XMG lt errnum gt lt description gt Usage Returned in response to a query or if enabled through PHILS NME XMG when an exception occurs Parameters lt errnum gt and lt description gt as defined in Appendix A Response Not Applicable 4 1 8 Description of Set Commands Set commands begin with the set command ID PHILS followed by the command type 4 1 8 1 Upload almanac data PHILS ALM Command PHILS ALM lt almanac gt Usage Allows data to be loaded into the Almanac store of the receiver This is used during aided initialisation and should be used if it is known that the data available to the receiver is invalid Parameters parameter range meaning lt 1 32 gt Satellite PRN number lt gpswk gt lt 0 9999 gt GPS week 2 bytes SV health in ASCII hex lt eccen gt 4 bytes Eccentricity in ASCII hex 2 bytes Almanac reference time in ASCII hex lt incl gt 4 bytes Inclination angle semicircles in ASCII hex lt asc gt 4 bytes Rate of ascension semicircles in ASCII hex lt axis gt 6 bytes Root of semi major axis in ASCII hex lt per gt 6 bytes Argument of perigee semicircle in ASCII
5. Version 1 2 SNA UM98008 Table4 Use of Serial Ports Case RTCM Input Command Input Output Default Disabled Port A or Port B Port A or B as programmed RTCM on A Port A Port B only Port A or B as programmed RTCM on B Port B Port A only Port A or B as programmed The RTCM input is enabled using the command PHILS RTC REM lt port gt and may be disabled by using the command PHILS RTC OFF 4 1 NMEA Interface The Philips Semiconductors GPS chip set supports the National Marine Electronics Association NMEA standard for navigation data interfacing 4 1 1 Conformance to NMEA 0183 Version 2 01 The interface conforms to NMEA 0183 Version 2 01 ASCII form though the following points should be noted The chip set does not incorporate level shifters for the physical layer of NMEA The interface is only compatible with NMEA 0183 2 01 when operated at 4800 baud The data levels are defined as follows on ve voltage stop bit state off 0 voltage start bit state This is inverted with respect to the voltage that appears on the physical NMEA connection The data format is defined in NMEA Standard 0183 Rev 2 01 Standard for Interfacing Marine Electronic Navigational Devices National Marine Electronics Association Reference 2 One message with the GP talker prefix is included which is not a standard NMEA approved sentence This is GPMSG 4 1 2 Supported NMEA Approved Sentences The
6. for the EXACT GPS Chip Set Version 1 2 SNA UM98008 4 1 8 17 Reset receiver hot start PHILS RST H Command PHILS RST H Usage Perform a Hot Start of the receiver Almanacs and ephemerides will be retained Parameters None Response NAK if unsuccessful Note This command will not generate an ACK response 4 1 8 18 Differential automatic mode selection PHILS RTC AUT Command PHILS RTC AUT lt yn gt Usage If there is no differential data input or the data is too old defined by command PHILS RTC MAX uncorrected data will still be output If automatic differential mode is disabled there will be no navigation solution output if there is no valid differential data Parameters yn lt Y N gt with Y enable differential automatic mode select N disable differential automatic mode select Response ACK NAK 4 1 8 19 Disable RTCM differential GPS input PHILS RTC OFF Command PHILS RTC OFF Usage Disables interpretation of RTCM DGPS input data from the presently selected port Parameters None Response ACK NAK 4 1 8 20 RTCM differential data age selection PHILS RTC MAX Command PHILS RTC MAX lt age gt Usage This command is only meaningful when differential mode with RTCM format is enabled It sets the maximum age in seconds of the differential data above which it will be considered invalid Parameters lt age gt i lt 0 3600 gt Default 30 s Response ACK NAK 32 Philips Semicondu
7. 4 1 7 5 RTCM message type 16 GPMSG 16 Sentence GPMSG 16 lt stid gt lt zzzz z gt lt s gt lt h gt lt ccc gt lt hhmmss gt lt text gt Usage Will occur in response to a query or when a message arrives from the DGPS station Parameters parameter range meaning stid zzzz z as defined for message type 3 gt lt S gt lt h gt lt CCc gt lt hhmmss gt lt text gt text from base station up to 80 alpha numeric characters Response Not applicable Message type 6 is the same except that the base station text is not included 4 1 7 6 Acknowledge PHILR ACK Sentence PHILR ACK 2A Usage Will be returned on successful reception of a set PHILS command Parameters None Response None 4 1 7 7 Negative acknowledge PHILR NAK Sentence PHILR NAK 27 Usage Will be returned if a set command is not understood or not completed Parameters None Response Not Applicable 4 1 7 8 Read port speed PHILR PRT Sentence PHILR PRT lt port gt lt speed gt Usage Returned in response to PHILQ PRT Parameters parameter range meaning lt port gt lt A B gt Port indicator lt speed gt lt 0 6 gt See Section 4 1 8 23 Serial port speed setup PHILS SPD Response Not Applicable 25 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 4 1 7 9 Show receiver ID PHILR RID
8. A full description of this software is provided in Section 7 on Page 58 There are three files contained on the disk exact exe exact hlp and README txt These files need to be copied into the appropriate working directory on the PC and executed from a windows environment The README txt contains important information about the starter kit contents and PC Host Demonstration S W Please read this before using the kit 5 3 Getting Started The following instructions allow the user to get up and running very quickly with the starter kit without being familiar with the full command set It is recommended that these instructions are followed carefully to ensure no problems are encountered with the board Before starting ensure that a power supply is available between 6 and 17 V and that the PC Host software has been loaded onto a suitable PC Connect appropriate power cable between PL101 on the PCB and the power supply DO NOT SWITCH POWER ON Connect suitable antenna to J301 on the PCB using a male SMA connector Either a passive antenna or active antenna requiring less than 25 mA drive current Connect PORT A J201 on the PCB to an available Com port on the PC using the 9 way D Type cable provided From the appropriate directory within file manager on the PC double click on EXACT EXE to run the evaluation software A window should appear titled Exact Host v2 1 containing 3 opened sub windows At the bottom left corner of t
9. Optimised Build of Materials Single Supply OEM Board 12 Component Count Comparison of Demo Board and OEM Application 13 Menu Functions of the Desktop Window 14 Menu Functions of NMEA Edit Window 15 Menu Function for the Incoming Messages Window 16 Menu Functions for Satellite Position Window 17 Menu Functions of the Receiver Position Window 18 Menu Functions for Receiver Motion Window 19 Menu Functions for Receiver Motion Window 20 List of Available Alternations for Receiver Status Al Exception Messages B1 List of Datums C1 Philips Default Operational Parameters List of Figures ll 2 Simplified Block Diagram GPS Demo Board GPS Demo Board Power Supply GPS Demo Board Digital Processor GPS Demo Board RF Front End Basic Structure of EXACT Host Software Desktop Window NMEA Edit Window with Commonly Used Messages Box Open Incoming Messages Window Satellite Position Window Receiver Position Window Receiver Motion Window Receiver Status Window User s Manual SNA UM98008 Page Number 12 13 17 20 21 22 23 43 44 51 54 57 59 60 61 62 63 64 65 65 67 68 70 11 47 48 49 50 58 59 60 61 62 63 64 65 Philips Semiconductors User s Manual SNA UM98008 User Interface Manual for the EXACT GPS Chip Set Version 1 2 1 INTRODUCTION EXACT is a Philips GPS Global Positioning System receiver circuit chip set which will provide th
10. RMC VTG ZDA MSG lt port gt lt A B gt Response The appropriate NMEA format sentence 4 1 9 2 Built in test PHILQ MEM Command PHILQ MEM lt port gt Usage The receiver will immediately carry out built in tests Parameters lt port gt A B Note If omitted result will be returned on the port from which the command was sent Response PHILQ MEM lt data gt This response is formatted in a way suitable for display directly on a standard terminal An example is shown here FFFO 0000 FFFF 0000 0000 field result meaning 1 FFFO Volatile memory test result Should always be FFFO 2 0000 Non volatile memory test result Non zero means checksum failed and this part of memory will be initialised and tested In that case the third field will show the result of this memory test The first time the receiver is used and each time that the PHILS RST command is issued this field will be non zero has no meaning 0000 Must always be zero 0000 ROM checksum result 0000 means checksum passed 3 FFFF If the second field is non zero meaning the checksum of the nonvolatile memory has failed this field will show the result of the test on that part of memory This result must be 8000 if memory passes the test If the second field is zero this field 35 Philips Semiconductors User s Manual SNA UM98008 User Interface Manual for the EXACT GPS Chip Set Version 1 2 4 1 9 3 Show current para
11. Resistor R115 R116 R202 12k 1 R108 R322 R203 0603 SM Resistor 0603 SM Resistor 0603 SM Resistor R310 R311 R307 0603 SM Resistor R106 1k 1 R117 R110 R111 R112 R204 0603 SM Resistor 0603 SM Resistor 0603 SM Resistor R319 0603 SM Resistor R320 R321 R323 R314 R315 R312 2k7 1 0603 SM Resistor 0603 SM Resistor 0603 SM Resistor R109 0603 SM Resistor R113 R114 6k8R 1 R313 R305 0603 SM Resistor 0603 SM Resistor 0603 SM Resistor R306 0603 SM Resistor L306 L307 22 uH 10 L301 L302 L308 1008 SM Inductor 1008 SM Inductor 1008 SM Inductor L303 L304 1008 SM Inductor L305 D301 SMV1204 133 0603 SM Inductor SOT23_G Alpha Industries Varicap BC848 V101 V102 SOT23_A NPN Transistor BC858 UAA1570 V103 V104 V105 V106 U301 55 SOT23_A PNP Transistor LQFP48_A Philips GPS RF Frontend Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 Table 11 Cost Optimised Build of Materials Single Supply OEM Board Continued Value Part Number Description SAA1575 U204 LQFP100 Philips GPS Baseband Processor M5M5256BVP U202 U203 28SOP400 Mitsubishi 256 kBit SRAM AM27C2048 70JC U205 PLCC44 AMD 2 MBit EPROM LP2951CM U103 850220 Adjustable Voltage Regulator MAX903ESA U302 850220 Maxim Comparator ZM33064 U206 SO
12. See appropriate set command in Section 4 on Page 19 A differentially corrected position is identified by looking at the 6 field of the GGA message A 1 indicates normal position data and 2 indicates a differentially corrected position 5 6 Saving User Preferences Once the receiver is set up in the user required state it is possible to save this setup to memory using the following command PHIL SAV Y Now each time the receiver is powered on it will be in the same setup state as that last saved 42 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 6 HARDWARE DESCRIPTION AND APPLICATION OVERVIEW This section outlines the main functions of the two ICs UAA1570 and SAA1575 with a view to system design More detailed information specific to each device can be found in the relative Data Sheets Reference 6 and 7 6 1 Front End RF IC UAA1570 The UAA1570 is a dual conversion receiver circuit designed to receive 1 575 GHz C A coded signals from the Navstar GPS satellite transmissions It is designed to operate with either an active or passive antenna providing two on board LNAs The frequency plan of the device is programmable allowing different reference frequencies to be used up to 35 MHz It has been designed to allow a first mix down frequency in the region of 41 MHz to enable low cost filter modules to be used in the application The second mixed
13. as follows From the Edit NMEA Messages window type the following commands PHILS ZDA lt time gt lt day gt lt month gt lt year gt eg PHILS ZDA 120000 1 10 1997 PHILS POS lt lat gt lt N S gt lt lon gt lt E W gt lt height gt eg PHILS POS 5055 00 N 00127 00 W 70 Now go to the Tools menu and click on send all messages The time date and approximate position have now been entered into the receiver and an acknowledgement window will be returned 41 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 5 5 Setting Up Differential Input If the user wishes to use differential GPS then the following procedure can be used If we assume that a differential receiver is being used with the EXACT demo board which outputs standard RTCM SC104 messages Connect RTCM receiver O P to Port B of the demo board J202 Send the following message to select Port B as the RTCM input PHILS RTC REM B Send the following command to give differentially corrected position output only PHIL RTC AUT N If the user requires automatic mode ie standard position output is provided when no differential data is available then N can be replaced by Y Send the following command to set the speed for the incoming RTCM messages PHIL SPD B 2 This sets Port B Baud Rate to 1200 If the 2 is replaced by 4 the Baud Rate would be set for 4800
14. coupled to discrete resonator or varactor components Ref CLK First IF Second IF 43 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 6 1 2 Internal LNAs Low Noise Amplifiers The UAA1570 has 2 on board LNAs allowing the use of either an active or passive GPS antenna Both amplifiers typically provide 15 5 dB of gain at 1 575 GHz from a 3 0 V supply If the application is intended to be used with a passive antenna both amplifiers should be implemented and the antenna should ideally be situated with the PCB ie absolute minimum cable loss If the application is intended for use with an active antenna then only the first amplifier needs to be implemented and a bandpass filter included between LNA2 and MX IN To minimise power consumption in this case the LNA1 input pin 45 should be grounded and the supply input for LNA1 pin 43 should be left open circuit In this case it is recommended that the external gain does not exceed 25 dB including cable losses If a higher gain antenna of 35 40 dB is used it may be possible to disable both LNAs Note In all cases supply for LNA2 Pin 1 must be provided Table9 RF Matching Impedances for LNAs and 1st Mixer Input Pin Real Ohms Imaginary Ohms Function LNA2 Input 86 j14 0 LNA2 Output 14 35 j34 0 1st Mixer Input 6 1 3 IF Filtering In this application discrete components are used
15. from the selected GPS receivers Table 17 Menu Functions of the Receiver Position Window Menu Options Description Tools Coordinate WGS84 set coordinate system to WGS84 System GRS80 set coordinate system to GRS80 Exit exit the window Ports COM x allocate isolate COM x to the window Re check All Ports re check all ports to provide an updated list of available ports Help call on line help The receiver position window is designed such that when maximised in height the graphical position is emphasised and when maximised in width the textual position is emphasised Position sd l Tools Ports Help Latitude 50 55 170 North scale 10 midiv Longitude 1 27 928 West Altitude 81 55m HDOP AS VDOP ser y Eu PDOP 4 3 Figure 11 Receiver Position Window The receiver position window is limited to a radius of approximately 30 km from the first plotted position This is a limitation of the PC host software which is not designed for production and intended only as an evaluation aid 63 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 7 6 Receiver Motion Window The receiver motion window displays the receiver bearing velocity and UTC time in text form The bearing is also displayed in form of a compass needle Receiver Motion Tools Ports Help Bearing 0 007 Velocity 0 3
16. package is available with the purchase of the chip set VCC supply voltages can be as low as 2 7 V for extremely low power operation Basic applications of the chip set include navigation and timing for users on land and marine The hardware and software interfaces are designed to allow easy connection to auxiliary devices such as other wireless terminals for integrated multi functional communication and data processing systems A complete demonstration and evaluation board is available to support evaluation of this chip set Custom software for specific application requirements can be quoted as required 1 1 Glossary 2D Two dimensional 3D Three dimensional Acquisition The process of finding and locking on to a satellite signal A D Analogue to Digital Converter Almanac A set of data describing the position of all satellites in the GPS constellation BIT Built In Test BPF Bandpass Filter Channel One of 8 physical hardware receivers available to demodulate a satellite signal Channel algorithm Constellation Low level software to manage each channel of the EXACT baseband receiver The arrangement of the satellites in the sky Correlator A system for computing the correlation of a signal with another local reference Datum A reference set of co ordinates which defines the model of the surface of the earth used for position computations The default is WGS 84 DGPS Differential GPS DOP Dilution Of Precision ie reduction
17. period PHILS 0 999 0 NME PHILS NME PER 36 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 4 1 9 4 Baud rate query PHILQ PRT Command PHILQ PRT lt port gt Usage Returns the baud rate of the port May be sent to either port A or B Parameters lt port gt lt A B gt Response PHILR PRT A 4 in example given Port A was at 4800 baud denoted by 4 4 1 9 5 Show receiver ID and firmware options PHILQ RID Command PHILQ RID lt port gt Usage Returns manufacturer ID receiver ID and firmware version Parameters port lt A B gt Response PHILR RID EX lt firmware gt example PHILR RID EX HCOO 4 1 9 6 RTCM status query PHILQ RTC Command PHILQ RTC lt port gt Usage Returns the RTCM differential status Parameters lt port gt lt A B gt Response An example of the typical response STATUS SYNC TYPE 00 STID 0000 STHE 0 000 QA 100 0 OFFSET 00 SETUP MODE OFF PORT B AUT Y MAX 0015 MSG With the following meanings SYNC indicates with a that synchronization between base and remote has been established TYPE indicates type of message being received 1 3 9 16 STID displays the received station ID STHE displays the received station health AGE Displays the age of received messages in seconds QA Displays the communication quality factor betwee
18. serial port speed The serial port data format is always 8 bit data no parity 1 stop bit 8N1 Note response will be made at the new port speed Parameters lt port gt lt A B gt speedID 0 1 2 3 4 5 6 where the speeds are indicated as follows 300 bps 600 bps 1200 bps 2400 bps 4800 bps 9600 bps 19200 bps Response ACK NAK at the new port speed 33 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 4 1 8 24 Set user defined datum parameters PHILS UDD Command PHILS UDD 0 lt da gt lt df gt lt dx gt lt dy gt lt dz gt lt drotx gt lt droty gt lt drotz gt lt scale gt Usage This command is used to input a map datum other than WGS 84 The user datum may be selected by enabling the datum USR using the PHILS DTM command Parameters parameter range meaning 0 Geodetic datum ID Always 0 for WGS 84 lt da gt lt 6300000 0 6400000 0 gt Semi major axis Default is 6378137 lt df gt lt 290 0 310 0 gt Flattening m Default is 298 25722356 lt dx gt lt gt lt 0 0 1000 0 gt Translation in x direction m Default is 0 0 lt dy gt lt gt lt 0 0 1000 0 gt Translation in y direction m Default is 0 0 lt dz gt lt gt lt 0 0 1000 0 gt Translation in z direction m Default is 0 0 lt drotx gt 0 0 Not used always 0 0 lt droty gt 0 0 Not u
19. to be individually programmed This may speed up acquisition of satellites It may be used in two cases 1 In response to an exception message indicating that the chip set is about to enter the Cold Start procedure 2 If receiver data is normal but the user wishes to override that data for instance when the receiver has been transported so far from its last valid position fix the stored data can be considered invalid After using PHILS POS or PHILS ZDA the system will detect the new data and go through a Warm Start procedure 4 DIGITAL INTERFACES The chip set supports 2 UARTs which can be configured for sending and receiving NMEA compatible messages and to receive RTCM SC104 Differential GPS data Proprietary commands are also supported to allow access to chip set features The chip set or receiver including the chip set communicates with the application system by two standard asynchronous serial ports The ports are referred to as A and B The default port for input commands and data to the receiver is Port A Port B is the default input for DGPS data Data from the receiver can be output to either of the ports depending on the configuration by commands from the application system In the default configuration Port A is used to communicate with the application system The ports may be programmed as shown in Table 4 on Page 20 19 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set
20. used per satellite Random Access Memory Radio Frequency The minimum signal level required to achieve a given level of performance Read Only Memory Real Time Clock Standard for differential correction data The type number of the RF front end IC of EXACT The type number of the digital baseband IC of EXACT The signal level of the satellite signal on a given channel as computed by the correlator hardware in the channel An unwanted signal Space Vehicle ie a satellite Time To First Fix Universal Asynchronous Receiver Transmitter The frequency at which navigation solutions are computed Universal Time Co ordinated Positive supply voltage Vertical Dilution of Precision Voltage Standing Wave Ratio a measure of quality of matching of impedance A datum World Geodetic System 1984 10 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 1 2 Features Eight parallel satellite channels tracking eight satellites at the same time Power Management functions Power down mode Reduced update rate option Supports true NMEA 0183 data protocol Direct differential RTCM SC 104 capability Rapid Time To First Fix TTFF RF input designed for active or passive Antenna Systems Multiple Operating Modes Automatic Mode Fixed 3D mode Fixed 2D mode In all the above modes UTC time is also available User programmable Elevation Mask User p
21. with a certain serial port s Close Log close a log file Exit end the program Windows NMEA Edit create an NMEA edit window NMEA Messages create an incoming messages window Satellite Position create a satellite position window Receiver Position create a receiver position window Receiver Motion create a receiver motion window Receiver Status create a receiver status window Ports COM x allocate isolate all the existing application windows to COM x Re check All Ports re check all ports to provide an updated list of available ports Help call the on line help 59 Philips Semiconductors User s Manual SNA UM98008 User Interface Manual for the EXACT GPS Chip Set Version 1 2 7 2 NMEA Edit Window The NMEA edit window allows the user to enter messages which may be saved to a file or sent to the receiver Messages can be typed in as outlined in Section 4 on Page 19 The TOOLS menu can then be used to either send all messages at once or only the message currently selected by the cursor Alternatively the file menu allows groups of messages to be loaded from or saved to a text file A commonly used messages box can be selected via the Messages menu option This option allows messages to be sent quickly and easily without understanding the full command set Table 14 Menu Functions of NMEA Edit Window Menu Options Description File Open open a file Close close Save save curre
22. 0 knots UTC Time 14 01 58 Figure 12 Receiver Motion Window Table 18 Menu Functions for Receiver Motion Window Menu Options Description Tools Exit exit the window Ports COM x allocate isolate COM x to the window Re check All Ports re check all ports to provide an updated list of available ports Help call on line help The receiver motion window is designed such that when maximised in height the graphical motion is emphasised and when maximised in width the textual motion is emphasised 64 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 7 7 Receiver Status Window The receiver status window allows the user to manually alter some of the parameters of the receiver such as DOP and elevation masks as well as position modes Options for measuring TTFF and selecting power down mode are also available It is important to note that the DOP and Elevation mask parameters do not reflect any changes made from the EDIT NMEA Messages window If the user is relying on the DOP and Elevation mask settings then they should not alter these values from the EDIT NMEA Messages Window ReceiverStaus Tools Ports Help Cold Start Not Heasured PowerSave OFF Warm Start Not Measured Not Measured Self Test Not Measured Solution Type automatic E Masks HDOP PDOP UDOP Fixed Elevation Figure 13 Receiver Status W
23. 1955 Iceland International 21 Indian Thailand Vietnam Everest 22 Indian Bangladesh India Nepal Everest 23 Ireland 1965 Ireland Modified Airy 24 Kertau 1948 West Malaysia Singapore Modified Everest 25 Liberia 1964 Liberia Clarke 1880 26 Luzon Philippines excluding Mindanao Island Clarke 1866 27 Massawa Eritrea Ethiopia Bessel 1841 68 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 Table B1 List of Datums Continued No Ellipsoid 28 Merchich Morocco Clarke 1880 29 Minna Nigeria Clarke 1880 30 Nahrwan Saudi Arabia Clarke 1880 31 North American 1927 North America Clarke 1866 CONUS 32 Alaska Alaska Clarke 1866 33 Canada Canada including Newfoundland Island Clarke 1866 34 Central America Belize Costa Rica El Salvador Guatemala Clarke 1866 Honduras Nicaragua Mexico 35 North American 1983 Alaska Canada Central America CONUS GRS80 Mexico 36 Old Egyptian Egypt Helmert 1906 37 Old Hawaiian Hawaii Clarke 1866 38 Oman Oman Clarke 1880 39 Ordnance Survey of England Isle of Man Scotland Shetland Airy Great Britain 1936 Islands Wales 40 Pitcairn Astro 1967 Pitcairn Island International 41 Quatar National Quatar International 42 Qornoq South Greenland International 43 Schwarzeck Nambia Bessel1841 in Nambia 44 South America 1969 Argentina Bolivia Braz
24. 30 4 1 8 13 Sleep control PHILS PWHR 31 4 1 8 14 Reset to defaults PHILS RST 31 4 1 8 15 Reset receiver cold start SPHILS RST C 31 4 1 8 16 Reset receiver warm start SPHILS RST W 31 4 1 8 17 Reset receiver hot start PHILS RST H 32 4 1 8 18 Differential automatic mode selection PHILS RTC AUT 32 4 1 8 19 Disable RTCM differential GPS input 6PHILS RTC OFF 32 4 1 8 20 RTCM differential data age selection SPHILS RTC MAX 32 4 1 8 21 Enable reception of differential GPS data SPHILS RTC REM lt port gt 33 4 1 8 22 Enable saving of parameters PHILS SAV 33 4 1 8 23 Serial port speed setup PHILS SPD 33 4 1 8 24 Set user defined datum parameters PHILS UDD 34 4 1 8 25 Upload initial real time clock value PHILS ZDA 34 4 1 9 Description of Query Commands 35 4 1 9 1 NMEA message query PHILQ message 35 4 1 9 2 Built in test SPHILQ MEM 35 4 1 9 3 Show current parameters PHILQ PAR 36 4 1 9 4 Baud rate query PHILQ PRT 37 4 1 9 5 Show receiver ID and firmware options PHILQ RID 37 4 1 9 8 status query PHILQ RTC 37 4 1 9 7 User defined datum query PHILQ UDD 38 4 1 9 8 Exception message query PHILQ XMG 38 4 1 10 Frequency of Data Output 39 4 2 Differential GPS 39 4 2 1 RTCM Differential Messages 39 5 QUICK START GUIDE 39 5 1 Hardware Setup 40 5 2 PC Software Installation 40 5 3 Getting Started 40 5 4 Aiding Initial Acquisition 41 5 5 Setting Up Differential Input 42 5 6 Saving User Preferenc
25. DEMO BOARD POWER SUPPLY Number Revision 801291_2 1 3 Figure 3 GPS Demo Board Power Supply 48 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 ELITEI 10F 6 3V PWR FAIL XTALI XTAL2 XTAL3 XTALA TXDo RXDO 1 RXDI to hi Nic NIC NIC test test2 GPI00 GPIOMDLYN GPIo4 To GPlos TI GPlOGT2 GPIO7 T2EX RCLK SCLK pid Dis REDAT RFLE PWRM RSTIME Title GPS DEMO BOARD DIGITAL PROCESSOR Number Revision 801291 3 1 3 Figure4 GPS Demo Board Digital Processor 49 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 gs 6 Uz3 5mds 1 11 TE Wu 9 5mm W 6 mis W 33 mis 100 ohms 50 ohms BPF301 Mrs T 206mis 73mm w koc L 442mis 10 5mm L 217mils 5 5mm W 6 mils W 33 BPF302 REF IN MEIOSI NIC LNALIN NC LNALOUT TANK LNALIN REDATA LNA2 OUT REDAT 1 ite 10mm E RF MX IN mis TO ohme SIG 11 IFLN BECP MX2IN N LIMIN P MX2IN P LIMIN N IERP BFCN C33533uF VCCLNAL GNDLNAL
26. IX lt mode gt Usage Select the source of the altitude value for 2 D position determination Parameters parameter range meaning lt mode gt lt 0 1 gt 0 the altitude is taken from either the one entered by the PHILS ALT command or the last one computed for a 3D position when PDOP is less than the PDOP mask 1 only use the altitude loaded from the application system using PHILS ALT Response ACK NAK 4 1 8 5 Mask PHILS HDP Command PHILS HDP lt value gt Usage Set the Horizontal Dilution of Precision mask The HDOP mask alters how the position computation is carried out see Section 3 3 3 4 on Page 16 Parameters parameter range meaning Response ACK NAK 4 1 8 6 Set local time zone PHILS LTZ Command PHILS LTZ lt shh gt lt mm gt Usage Sets the time zone offset to be added to local time to get GMT Parameters parameter range meaning lt shh gt lt gt lt 00 13 gt GMT localtime timeoffset hours lt 00 59 gt GMT localtime timeoffset minutes Response ACK NAK Note The default is 00 00 ie a time offset of zero This command affects the output of the GPZDA response 28 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 4 1 8 7 Enable NMEA messages PHILS NME Command PHILS NME lt string gt lt port gt lt bool gt lt per gt Usage Enable disable the periodic output
27. Interruption of 60 seconds Re acquisition 5 seconds Interruption of 600 seconds Re acquisition 20 seconds UART I O 2 UARTS with selectable baud rates from 300 to 19 2 k 2 1 1 Controller Functionality Operating modes Automatic Mode FIX Modes UTC Time Only 1 satellite only Fixed 2D 3 satellites minimum Fixed 3D 4 satellites minimum UTC Time Will output current UTC time Built in Real Time Clock for fast acquisition of satellites Elevation Mask Allows user to set minimum elevation angle for satellites to be used in a solution output DOP Mask and switch User may set the maximum value of PDOP and HDOP for which any 2D or 3D solution will be made Working Environment Velocity 400 m sec Acceleration lt 4g 39 2 sec at 1 second navigation update rate Altitude 18 000 m 13 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 2 2 Electrical Specifications Operating Voltage 2 7 V minimum 5 5 V maximum Power Consumption 650 mW at 3 3 V 25 C Operating temperature range 40 C minimum 85 C maximum 2 3 RF Specifications Input Impedance 50 Ohms Noise Figure 2 5 dB RF Sensitivity 130 dBm 3 MODES OF OPERATION The chip set operates in four modes Off Sleep Navigating Built In Test mode BIT 3 1 Off Mode The power may be disconnected from the chip set but applied to
28. Latitude Longitude GPGSA NMEA GPS DOP and active satellites GPGSV NMEA GPS Satellites in view GPMSG Differential Message RTCM SC104 types 3 and 16 GPRMC NMEA Recommended Minimum Specific GPS Data GPVTG NMEA Course over ground and ground speed GPZDA NMEA Time and Date PHILR ACK Acknowledge of set command PHILR NAK Negative acknowledge of set command PHILR PRT Port Speed PHILR RID Receiver ID PHILR XMG lt errnum gt Last Exception Number 21 Philips Semiconductors User Interface Manual for the EXACT GPS Chip Set 4 1 5 Summary of Set Commands Version 1 2 User s Manual SNA UM98008 Table 6 Summary of Set Commands Command Description PHILS ALM lt almanac gt Upload Almanac Data PHILS PEM lt angle gt PHILS PMD lt mode gt PHILS POS lt lat gt lt NS lt lon gt lt EW gt lt sign gt lt ht gt PHILS ALT lt signvalue gt 2D Altitude PHILS DTM lt n gt Select Datum PHILS FIX mode 2D fix mode PHILS HDP value Mask HDOP PHILS LTZ lt offset gt Set local time zone PHILS NME lt string gt lt port gt lt bool gt lt per gt Enable NMEA PHILS NME PER lt time gt Receiver Update Interval PHILS PDP value Mask PDOP Mask Elevation Angle Navigation Position Mode Upload Initial Position Data PHILS PWR lt mode gt Sleep Control PHILS RTC AUT lt yn gt PHILS RST Reset to default values PHILS RST C Initiate Cold Start
29. PHILS RST W Initiate Warm Start PHILS RST H Initiate Hot Start Differential Automatic Mode Enable PHILS RTC OFF Disable differential GPS input PHILS RTC MAX lt age gt Differential Data Age PHILS RTC REM lt port gt PHILS SAV lt yn gt PHILS SPD lt port gt lt speed ID PHILS UDD lt da gt lt df gt lt dx gt lt dy gt lt dz gt Enable differential GPS input Save parameters Serial Port Speed Set User Defined Datum parameters PHILS ZDA lt rtc gt Upload Initial Real Time Clock Value 22 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 4 1 6 Summary of Query Sentences Table 7 Summary of Query Sentences Command Description PHILQ lt string gt lt port gt NMEA Raw data query PHILQ MEM lt port gt Memory test PHILQ PAR Receiver Parameter Status PHILQ PRT Port Baud Rate Query PHILQ RID Receiver ID PHILQ RTC RTCM Status Query PHILQ UDD User Defined Datum Query PHILQ XMG port Exception Message Query 4 1 7 Description of Responses 4 1 7 1 Standard NMEA responses Standard NMEA responses are returned in the NMEA format These are GPALM GPGGA GPGLL GPGSA GPGSV GPRMC GPVTG and GPZDA Please refer to the NMEA Specification NMEA0183 V2 01 for details of these Non standard responses are returned in the same format as NMEA but are not defined in the standard
30. Position or Almanac System will enter Cold Start state due to lack of valid data 04 BIT completed End of built in test routines 05 Cannot converge with 4 or more No navigation solution in auto mode with satellites 4 satellites 06 Cannot converge with 3 satellites No navigation solution in auto mode with 3 satellites 07 Too few satellites for 3D solution No navigation solution in Fixed 3D mode as only 3 satellites 08 No 3D solution due to PDOP mask No navigation solution in Fixed 3D mode due to exceeded bad PDOP 09 Too few satellites for 2D solution No navigation solution in Fixed 2D mode as only 2 or fewer satellites 10 No 2D solution due to PDOP mask No navigation solution in Fixed 2D mode due to exceeded bad PDOP 11 Time only No Solution No satellites above mask angle 12 Solution valid A valid solution is now being generated Note In all cases exceptions are generated on transitions from one state to another thus they will normally only occur once Thus exception message number 12 will be generated whenever the EXACT chip set determines that a valid solution is now available whereas previously it was not available Note The validity output may also be determined at any time by examining the validity flag within the GPRMC or GPGGA messages refer to Reference 2 67 Philips Semiconductors User s Manual SNA UM98008 User Interface Manual for the EXACT GPS Chip Set Version 1 2 APPENDIX B L
31. SM Capacitor NPO 2 6 8 pF C315 C316 0603 SM Capacitor NPO 1 C310 0603 SM Capacitor NPO 2 C317 C318 0603 SM Capacitor NPO 1 C301 0603 SM Capacitor NPO 1 1 uF 16 V C345 TANTAL A Polarised Capacitor 1 uF 20 V t C107 C115 TANTAL_A Polarised Capacitor 10 uF 10 C109 C116 TANTAL_C Polarised Capacitor 10 uF 6 3 V C111 C209 TANTAL_A Polarised Capacitor 51 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 Table 10 Build of Materials for Demonstration Board Continued Value Tolerance Part Number Description 22 uF 16 V 10 C108 C110 TANTAL D SM Capacitor 2 2 22 uF 6 3 V 10 C113 C114 TANTAL_C SM Capacitor 2 47 uF 6 3 V C225 C226 TANTAL_C SM Capacitor 1 R201 R301 R302 R304 0603 SM Resistor N gt 10k 1 R205 R206 R316 R317 0603 SM Resistor R318 R326 R327 R115 R116 R202 0603 SM Resistor 2 R108 R322 0603 SM Resistor 1 R203 0603 SM Resistor 1 R106 0603 SM Resistor 1 R117 0603 SM Resistor 4 1M R110 R111 R112 R204 0603 SM Resistor 8 1RO R101 R102 R103 R211 0603 SM Resistor R212 R213 R216 R325 1 R319 0603 SM Resistor 3 R222 R223 R224 0603 SM Resistor 1 R120 0603 SM Resistor 3 R320 R321 R323 0603 SM Resistor 2 R314 R315 0603 SM Resistor 1 d R122 0603 SM Resistor R312 0603 SM Resistor R109 R207 0603 SM Resistor R113 R114 0603 SM R
32. Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 4 1 8 10 Position elevation mask angle PHILS PEM Command PHILS PEM lt angle gt Usage Sets the value of the elevation mask angle below which a satellite will not be used in a position computation Parameters angle lt 0 90 gt degrees Default angle 5 Response ACK NAK 4 1 8 11 Navigation position mode PHILS PMD Command PHILS PMD lt mode gt Usage The receiver will change its mode according to the parameter Parameters parameter range meaning lt mode gt 0 Fixed 3D position solution 2 Fixed 2D 3 Automatic positioning mode Default positioning mode Response ACK NAK 4 1 8 12 Upload initial position data PHILS POS Command PHILS POS lt lat gt lt NS gt lt lon gt lt EW gt lt sign gt lt ht gt Usage Allows data to be loaded into the Position store of the receiver This is used during aided initialisation and should be used if it is known that the data available to the receiver is invalid Parameters lt lat gt lt 0 90 0 gt latitude in eee decimal minutes ddmm mmmm lt NS gt lt N S gt North N or South S 0 180 0 gt saa in degrees decimal minutes dddmm mmmm lt EW gt lt E W gt East E or West W lt sign gt lt gt lt 0 99999 99 gt ellipsoidal height in meters Response ACK NAK In normal usage this command should not b
33. Standard 0183 Rev 2 01 Standard for Interfacing Marine Electronic Navigational Devices National Marine Electronics Association RTCM Recommendations of Special Committee 104 Differential Navstar GPS Service Version 2 1 Radio Technical Commission for Maritime Service PO Box 19087 Washington DC 20036 Ashtech SCA12 Receiver SCA12S Sensor Interface Guide and Operating Manual Firmware Version 1D00 Document Number 630007 Revision A April 1995 Ashtech GPS Sensor Operating Manual and Interface Guide Document Number 600086 Revision B Publication Date 27 July 1993 Data Sheet Preliminary Specification UAA1570 Front End Receiver Circuit Data Sheet Preliminary Specification SAA1575 GPS Baseband Processor Electronic Filtering Design Handbook Author B Williams Published by McGraw Hill Book Company 1981 ISBN 0 07 070430 9 Handbook of Filter Synthesis Author Anatol Zverev Published by John Wiley amp Sons Inc 1967 66 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 APPENDIX A Exception Messages This section documents the exception messages which will be produced Table A1 Exception Messages Exception m gt Number Description Meaning 01 SRAM corrupted System will enter Set Defaults state due to lost data 02 Real Time Clock Corrupt System will enter Cold Start due to loss of time information 03 No
34. T223 Zetex Voltage Monitor 4 6 V 2 1 1 1 1 1 ZM33164 U207 SOT223 Zetex Voltage Monitor 4 8 V 1 1 1 1 1 MF1012S 1 BPF302 MF1012S 1 Mitsubishi 1 575 GHz BP Filter TCO 987Q X301 14 40MHz Toyocom TCXO 32 768 kHz 202 MC 406 Crystal SMA F J301 Female SMA Connector 3V 170 mAh B101 Lithium Battery 1 10 Way Header 10 Way Connector Power Comms Table 12 provides a summary of components used on the demonstration board compared with the number required for a typical OEM application In this instance the OEM application would be a single 5 V solution with no onboard RS232 driver circuitry The changes required to the schematic to produce a typical OEM board can be decsribed as follows 1 Remove 5 V regulators and associated circuits LM317T 2 Remove RS232 driver IC 21 and associated components and connectors 3 Remove first RF bandpass filter BPF301 and associated components Input originally to 45 of UAA1570 is now taken to Pin3 Pin45 is now grounded and Pin43 left open circuit as LNA1 is not required 4 Assuming default frequency plan is used no communication is required between the RF and Baseband ICs Therefore R208 R210 and R222 R224 no longer required 5 All 1RO supply resistors and OR resistors can be removed Note that R310 and R311 must remain to optimise noise reduction on the mixer supply inputs 56 Philips Semiconductors User Interf
35. These are GPMSG Proprietary responses are prefixed with the string PHILR All responses have a Checksum attached to them These are not shown in the cases below where the data is variable 23 Philips Semiconductors User Interface Manual for the EXACT GPS Chip Set User s Manual Version 1 2 SNA UM98008 41 7 2 RTCM message type 1 GPMSG 1 Sentence GPMSG 1 lt stid gt lt zzzz z gt lt s gt lt h gt lt ccc gt lt hhmmss gt lt e gt lt VV gt lt Spppp pp gt lt sr rrr gt lt iii gt Usage Will be received in response to the appropriate query Parameters parameter range meaning lt stid gt lt 0000 1023 gt station ID lt ZZZZ Z gt lt 0000 0 9999 9 gt Z count in seconds and tenths of seconds lt S gt lt 0 9 gt sequence number lt h gt lt 0 7 gt station health lt CCC gt lt 000 999 gt total number of characters after the time item lt hhmmss gt lt 00 23 gt lt 00 59 gt lt 00 59 gt UTC time of position fix in hours minutes and seconds lt e gt lt 0 9 gt user differential range error vv lt 01 32 gt Satellite PRN lt spppp pp gt lt gt lt 0000 00 9999 99 gt Satellite pseudo range correction in metres lt sr rrr gt lt gt lt 0 000 9 999 gt range rate correction in metres s iii lt 000 999 gt Issue of Date Epoch Note Message type 9 is the same except that message type 1 h
36. a 4 DIGITAL INTERFACES 4 1 NMEA Interface 4 1 1 Conformance to NMEA 0183 Version 2 01 4 1 2 Supported NMEA Approved Sentences 4 1 3 Overview of Proprietary Commands 4 1 4 Summary of Responses 4 1 5 Summary of Set Commands 4 1 6 Summary of Query Sentences 4 1 7 Description of Responses 4 1 7 1 Standard NMEA responses 41 7 2 RTCM message type 1 SGPMSG 1 417 3 RTCM message type GPMSG 3 4 1 7 4 RTCM message type 9 GPMSG 9 4 1 7 5 message type 16 GPMSG 16 4 1 7 6 Acknowledge PHILR ACK 4 1 7 7 Negative acknowledge PHILR NAK 4 1 7 8 Read port speed PHILR PRT 4 1 7 9 Show receiver ID PHILR RID 4 1 7 10 Last exception message PHILR XMG User s Manual SNA UM98008 Page Number Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 Table of Contents Cont d Page Number 4 1 8 Description of Set Commands 26 4 1 8 1 Upload almanac data PHILS ALM 26 4 1 8 2 Load 2D altitude PHILS ALT 27 4 1 8 3 Set datum PHILS DTM 27 4 1 8 4 20 Altitude source selection PHILS FIX 28 4 1 8 5 Mask PHILS HDP 28 4 1 8 6 Set local time zone PHILS LTZ 28 4 1 8 7 Enable NMEA messages PHILS NME 29 4 1 8 8 Receiver update interval SPHILS NME PER 29 4 1 8 9 Mask PDOP PHILS PDP 29 4 1 8 10 Position elevation mask angle SPHILS PEM 30 4 1 8 11 Navigation position mode PHILS PMD 30 4 1 8 12 Upload initial position data SPHILS POS
37. ace Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 Table 12 Component Count Comparison of Demo Board and OEM Application Component Description Demo Board Qty OEM Board Qty Surface Mount Ceramic Chip Capacitors 72 61 Surface Mount Electrolytic Capacitors 13 6 Surface Mount Resistors 57 35 Surface Mount Inductors 8 8 Bandpass Filter at 1 57542 GHz 1 General Purpose Diodes and Transistors 11 6 Varicap Diode 1 1 Voltage Monitors 4 8 V 4 6 V 2 2 Variable Voltage Regulator 5V Outputs 2 0 Variable Voltage Regulator 3V Output 1 1 RS232 Driver 1 0 Philips GPS RF Front End IC 1 1 Philips GPS Baseband Processor IC 1 1 2 MBit OTP EPROM 1 1 256 kBit SRAM 2 2 Comparator IC Split Supply 1 1 TCXO 14 40 MHz 15 ppm 1 1 Crystal 30 00 MHz 50 ppm 1 1 Standard Watch Crystal 1 1 Lithium Battery Cell 1 1 9 Way D Type Connector 2 0 10 Way Connector Power and Communications Interface 0 1 RF Antenna Connector 1 1 57 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 7 PC DEMONSTRATION SOFTWARE DESCRIPTION The EXACT Host software package is intended to produce a user interface to the Philips EXACT GPS receiver chip set The standard NMEA messages are supported and displayed in textual and graphical format The top level control of the interface is the desktop window which can be used to create six ty
38. ad correction information the last 5 fields e vv spppp pp sr rrr iii for all satellites and each message type 9 has correction information for up to 3 satellites per transmission 4 1 7 3 RTCM message type 3 GPMSG 3 Sentence GPMSG 3 lt stid gt lt zzzz z gt lt s gt lt h gt lt ccc gt lt hhmmss gt lt SXxxXXXX XX gt lt 8 gt lt 52222222 22 gt Usage Will be received in response to the appropriate query Parameters parameter range meaning lt stid gt lt 0000 1023 gt station ID lt 7777 7 gt lt 0000 0 3600 0 gt Z count in seconds and tenths of seconds lt gt lt 0 7 gt sequence number lt h gt lt 0 7 gt station health ccc lt 000 999 gt total number of characters after the time item lt hhmmss gt lt 00 23 gt lt 00 59 gt lt 00 59 gt GPS time of position fix in hours minutes and seconds lt SXXXXXXX XX gt lt gt lt 0000000 00 9999999 99 gt metric X distance from geo centre Syyyyyyyy yy lt gt lt 0000000 00 9999999 99 gt metric Y distance from geo centre SZZZZZZZ 22 lt gt lt 0000000 00 9999999 99 gt metric Z distance from geo centre Response Not applicable 24 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 417 4 RTCM message type 9 GPMSG 9 This message is identical to GPMSG 1 as described earlier in this section
39. ctors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 4 1 8 24 Enable reception of differential GPS data PHILS RTC REM port Command PHILS RTC REM lt port gt Usage Enables reception of RTCM data on the specified port Note that once a particular port has been selected the user must use the other port for input of commands see Table 3 on Page 17 Parameters parameter range meaning lt port gt lt A B gt Select the named port for RTCM input 4 1 8 22 Enable saving of parameters PHILS SAV Command PHILS SAV lt yn gt Usage If the command PHILS SAV Y is sent the parameters of the system will be saved to battery backed RAM at that point At the next power on eg hardware reset to exit the power saving mode these saved parameters will be restored If parameters were changed after issuing the PHILS SAV Y command but before the receiver was powered down those changes will be lost at the next power up If the command PHILS SAV N is sent the parameters of the system will always be set to default values each time EXACT is powered up ie each time a hardware RESET is issued Parameters yn lt Y N gt with Y save parameters now and restore them after a hard reset N return parameters to default values after a hard reset Response ACK NAK 4 1 8 23 Serial port speed setup PHILS SPD Command PHILS SPD lt port gt lt speed ID gt Usage Set the
40. down signal in the region of 3 MHz is then sampled by the baseband processor SAA1575 using a 1 Bit A D converter on board the RF IC The divider ratios are fixed for this application but can be programmed by the baseband device via a 3 wire interface This interface also allows the RF IC to be powered down under software control from the baseband device More detailed information on the features of the UAA1570 can be found in the data sheet Reference 6 Some of the main application issues are covered in the following sections and a typical application is provided in the schematics in Section 6 3 1 6 1 1 Reference Clock and Frequency Plan The system firmware provided with the baseband IC SAA1575 has been designed to be used with a 14 40 MHz crystal oscillator within 15 ppm The reference clock input to the RF IC must be limited to no more than 700 mV rms There are 3 dividers that can be programmed L n and r which are detailed in the relevant data sheet If these registers are left in the default power up state and a 14 4 MHz reference clock is used the following frequency plan will result This is the frequency plan of the demonstration hardware Table 8 Default Frequency Plan using 14 4 MHz Reference Clock SCLK Set by Firmware 14 4 MHz 41 4 MHz 3 48 MHz 4 8 MHz The TANK circuit around pins10 of the RF IC should use absolute minimum trace lengths and widths and very close proximity to the appropriate supply pins 9 and 11 when a c
41. e needed However it can be used in cases where it is known that the position data is significantly different as it will speed up acquisition of the satellites 30 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 4 1 8 13 Sleep control PHILS PWR Command PHILS PWR lt sleepmode gt Usage To disable or enable the running of the hardware blocks for power control purpose The system can only be woken up again by applying a reset or any input to the serial ports parameter range meaning lt sleepmode gt OFF all blocks disabled Response None 4 1 8 14 Reset to defaults PHILS RST Command PHILS RST Usage Resets all user definable parameters to default values Note that after this command the port speed options will need to be resent Parameters None Response ACK NAK 4 1 8 15 Reset receiver cold start PHILS RST C Command PHILS RST C Usage Perform a Cold Start of the receiver Almanacs and ephemerides will be cleared Parameters None Response NAK if unsuccessful Note This command will not generate an ACK response 4 1 8 16 Reset receiver warm start PHILS RST W Command PHILS RST W Usage Perform a Warm Start of the receiver Almanacs will be retained Ephemerides will be cleared Parameters None Response NAK if unsuccessful Note This command will not generate an ACK response 31 Philips Semiconductors
42. e user with a GPS receiver function as well as an embedded controller to convert the raw satellite data to a navigation solution The controller is capable of receiving Differential GPS DGPS data which will allow position accuracy to be within 5 meters Unlike other GPS chip sets the Philips solution provides the user with embedded firmware which provides the complete navigation solution Philips technology will allow you to think of GPS as what it really is a general purpose utility that provides position and time information The Philips solution is a two chip set The RF or front end chip UAA1570 is a standard double conversion spread spectrum radio receiver circuit It is designed to use low cost filter components and common low cost crystals When used with a local antenna system there is no need for an external LNA The baseband processor SAA1575 contains the controller core plus the required GPS correlator hardware to decode the GPS satellite signals received from the front end The processor will also accept standard RTCM SC104 differential input signals to provide the best position accuracy when Selective Availability SA is turned on External static RAM is required allowing low power applications The external ROM EPROM contains the complete software solution to solve the navigation solution Information in and out of the GPS receiver is via standard serial UARTs with user programmable baud rates A complete software driver
43. es 42 Philips Semiconductors User Interface Manual for the EXACT GPS Chip Set Version 1 2 Table of Contents Cont d 6 HARDWARE DESCRIPTION AND APPLICATION OVERVIEW 6 1 Front End RF IC UAA1570 6 1 1 Reference Clock and Frequency Plan 6 1 2 Internal LNAs Low Noise Amplifiers 6 1 3 IF Filtering 6 1 4 Sample Clock and SIGN Bit 6 1 5 Programming the RF IC 6 2 Baseband IC SAA1575 6 2 1 RAM and ROM Access 6 2 2 UARTS 6 2 3 Power Up and Reset Procedure 6 2 4 Power Down and Battery Backup 6 3 PCB Description 6 3 1 Schematic Diagrams 6 3 2 PCB Build of Materials 6 3 3 Board Costing Consiiderations 7 PC DEMONSTRATION SOFTWARE DESCRIPTION 7 1 Desktop Window 7 2 NMEA Edit Window 7 3 Incoming Messages Window 7 4 Satellite Position Window 7 5 Receiver Position Window 7 6 Receiver Motion Window 7 7 Receiver Status Window 8 REFERENCES APPENDICES A Exception Messages B List of Datums C Stored Parameters User s Manual SNA UM98008 Page Number 67 68 70 Philips Semiconductors User Interface Manual for the EXACT GPS Chip Set Version 1 2 List of Tables 1 Position Accuracy of EXACT 2 Acquisition Time To First Fix 3 Mode Transitions from Power Up 4 Use of Serial Ports 5 Summary of Response 6 Summary of Set Commands 7 Summary of Query Sentences 8 Default Frequency Plan using 14 4 MHz Reference Clock 9 RF Matching Impedances for LNAs and ist Mixer Input 10 Build of Materials for Demonstration Board 11 Cost
44. esistor 6k8 R R313 0603 SM Resistor R119 R305 0603 SM Resistor R306 0603 SM Resistor PO H PM R303 R307 0603 SM Resistor 180 nH 10 L306 1307 1008 SM Inductor Coilcroft 1008CS 181XKBC 22 uH 10 L301 L302 1008 SM Inductor TOKO FSLU 2520 220 27 uH 10 L308 1008 SM Inductor TOKO FSLU 2520 270 330 nH 10 L303 L304 1008 SM Inductor Coilcroft 1008CS 331XKBC 52 Philips Semiconductors User Interface Manual for the EXACT GPS Chip Set Version 1 2 User s Manual SNA UM98008 Table 10 Build of Materials for Demonstration Board Continued Description LL4007 0805 SM Inductor Coilcroft 0805CS 060XJBC SMV1233 004 SOT23 G Alpha Industries Varicap SOT23 A NPN Transistor BC858 SOT23 A PNP Transistor UAA1570 LQFP48 A Philips GPS RF front end SAA1575 LQFP100 Philips GPS Baseband Processor M5M5256BVP 28SOP400 Mitsubishi 256 kBit SRAM AM27C2048 70JC PLCC44 AMD 2 MBit EPROM LM317T LP2951CM TO220 Adjustable Linear Regulator 850220 Adjustable Voltage Regulator 21 28SSOP Maxim RS232 Tx Rx MAX903ESA 8S0220 Maxim Comparator SOT223 Zetex Voltage Monitor 4 6 V SOT223 Zetex Voltage Monitor 4 8 V TCO 987Q MF1012S 1 Mitsubishi 1 575 GHz BP Filter 14 40 MHz Toyocom TCXO 30 MHz Golledge SM Crystal GSX 1B 32 768 kHz SMA F MC 406 Crystal 9 Way MALE D T
45. following commands from the NMEA 0183 V2 01 standard are supported They will be prefixed by GP as the talker identifier ALM GPS Almanac Data GGA GPS Fix data GLL Geographic Position Latitude Longitude GSA GPS DOP and Active Satellites GSV GPS Satellites in view RMC Recommended Minimum Specific GPS TRANSIT Data VTG Course over ground and ground speed ZDA Time and Date 20 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 4 1 3 Overview of Proprietary Commands All the option values are ASCII character all upper case strings Commands including commands and query commands are from the application system to the receiver When a command is received the receiver will give a response to the command If the command is not a query command the response is an acknowledge or fail to acknowledge response otherwise the response is the queried data The notation used is as follows lt gt contains a value of the type indicates boolean OR surrounds optional items ellipsis zero or more of the preceding item char a valid NMEA 0183 V2 01 ASCII character string char char bool ON OFF yn Y N Note Default options are shown in underlined 4 1 4 Summary of Responses Table 5 Summary of Response Command Description GPALM NMEA GPS Almanac GPGGA NMEA Position Fix GPGLL NMEA Geographic
46. for both the first and second IF filters It is recommended that the first mixer IF1 outputs are balanced although this is optional on the second mixer IF2 outputs Both the IF1 and IF2 outputs should be DC coupled to the RF supply via first IF filter inductors or RF chokes This supply should be decoupled close to these inductors with a minimum 1 uF tantalum capacitor The frequency of the first and second IFs and the sampling clock can be altered to allow standard filter components to be used in the application If this was required the firmware supplied with the baseband IC SAA1575 would have to be altered to meet the application requirements The IF filters used on the demo board have been designed using a Butterworth 3 dB Down k and q approach as detailed in Reference 9 Suitable filter design text books are given in Reference 8 and 9 6 1 4 Sample Clock and SIGN Bit The reference clock of 14 40 MHz is divided down by the baseband processor SAA1575 to 4 8 MHz and used to sample the SIGN Bit output from the RF IC The maximum DC coupled sample clock input level to the RF IC should not exceed 75 of the limiter supply VCCLIM on pin 31 The threshold level of the sample clock input is set to half of the VCCLIM supply The SIGN Bit TTL output on pin 34 should be carefully isolated from all analogue traces and components especially the second IF filter components at the limiter input Care should also be taken to prevent coupling int
47. he screen are 3 iconised windows All The available windows are detailed in Section 7 The opened windows will provide all incoming NMEA messages as well as receiver and satellite position information Switch on the power supply and ensure that the current drawn is approximately 200 mA with antenna fitted and 170 mA with no antenna fitted In the main Exact Host window select Ports using either the mouse or the ALT P command If the software has already detected that the hardware is connected to a Com port the menu will contain the following items 40 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 Ports COM Philips Re check All Ports If this is the case click COM 1 Philips This will automatically connect all available windows to this Com port If the receiver has not been detected yet click on Re check All Ports which should identify the hardware is now connected If the software consistently fails to detect the hardware check the cable connections to the PC and the board Double click on the Edit NMEA Messages icon in the bottom left corner of the Screen From the cursor and in upper case characters type the following command PHILS RST Now click on the menu Tools and then on the option Send Current Message A full system reset command has now been sent which initialises all parameters to their default settings and clea
48. hex lt lonasc gt 6 bytes Longitude of ascension mode semicircle in ASCII hex 6 bytes Mean anomaly semicircle in ASCII hex lt clk gt 3 bytes Clock parameter seconds in ASCII hex 3 bytes Clock parameter sec sec in ASCII hex 26 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 Note Data is in the format of the NMEA Almanac message GPALM The data should be sent using 32 separate messages one per satellite Response ACK NAK In normal usage this command should not be needed However it can be used in cases where it is known that the almanac data is significantly different as it will speed up acquisition of the satellites 4 1 8 2 Load 2D altitude PHILS ALT Command PHILS ALT lt sign gt lt value gt Usage Set the altitude for 2 D solution Parameters parameter range meaning lt sign gt lt gt lt 0 99999 99 gt metres Default is 0 Response ACK NAK 4 1 8 3 Set datum PHILS DTM Command PHILS DTM lt s gt Usage Select the datum which will be used to affect position output Parameters parameter range CS lt gt lt W84 USR gt WGS84 or user defined using PHILS UDD 27 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 4 1 8 4 2 Altitude source selection PHILS FIX Command PHILS F
49. il Chile Colombia South America 1969 Ecuador Guyana Paraguay Peru Venezuela Trinidad Tobago 45 Timbalai 1948 Brunei East Malaysia Sarawak Sabah Everest 46 Tokyo Japan Korea Okinawa Bessel 1841 47 Zanderij Surinam International 48 WGS 1972 WGS72 49 WGS 1984 WGS84 69 Philips Semiconductors User Interface Manual for the EXACT GPS Chip Set User s Manual Version 1 2 SNA UM98008 APPENDIX C Stored Parameters The following parameters will be stored in SRAM which may be maintained by the keep alive voltage whilst the EXACT chip set is powered down This set is chosen so that basic operation may be maintained across loss of main power 70 PHILS ALT PHILS DTM PHILS FIX PHILS HDP PHILS LTZ PHILS NME PHILS NME PER PHILS PDP PHILS PEM PHILS PMD PHILS SPD PHILS UDD Note Parameters associated with ports A and B will be stored independently for each port Table C1 Philips Default Operational Parameters Item Default Value Set Command Latitude None PHILS PO Longitude None PHILS POS Altitude None PHILS POS Navigation Position Mode 3 PHILS PMD 2D Altitude 0 PHILS ALT UTC time 00 00 00 PHILS ZDA HDOP Mask 4 PHILS HDP PDOP Mask 6 PHILS PDP VDOP Mask 4 n a Elevation Mask 5 degrees above horizon PHILS PEM Datum WGS 84 PHILS DTM DGPS positioning OFF PHILS RTC Auto Differential Mode Enabled PHILS RTC AUT Diffe
50. indow Table 19 Menu Functions for Receiver Motion Window Menu Options Description Tools Exit exit the window Ports COM x allocate isolate COM x to the window Re check All Ports re check all ports to provide an updated list of available ports Help call on line help Table 20 List of Available Alternations for Receiver Status Buttons Cold Start initiate cold start and measure the TTFF Warm Start initiate warm start and measure the TTFF Hot Start initiate hot start and measure the TTFF Self Test run the built in test routine which is a feature of the Baseband IC Combo Box Solution Type allows user to manually specify different modes of positioning Masks HDOP allows user to alter the HDOP mask VDOP VDOP mask value fixed in software PDOP allows user to alter the PDOP mask Elevation allows user to type in the parameter for the elevation mask The elevation and DOP masks can be changed by clicking once on the current value and then typing the new mask setting followed by lt CR gt 65 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 1 2 3 4 5 6 7 8 9 REFERENCES Navstar GPS Space Segment Navigation User Interfaces ICD GPS 200 Revision B Rockwell International Satellite Systems Division 2600 Westminster Boulevard PO Box 3644 Seal Beach CA 90740 7644 NMEA
51. ist of Datums The datums may be implemented by changing the semi major axis and inverse flattening parameters used in the navigation solution see Section 4 1 8 24 Set user defined datum parameters PHILS UDD to the values specified by the Defence Mapping Agency Table B1 List of Datums No kea Ellipsoid 1 ARC 1950 Botswana Lesotho Malawi Swaziland Clarke 1880 Zaire Zambia Zimbabwe 2 ARC 1960 Kenya Tanzania Clarke 1880 3 Australian Geodetic 1966 Australia Tasmania Island Australian National 4 Australian Geodetic 1984 Australia Tasmania Island Australian National 5 Bogota Observatory Columbia International 6 Campo Inchauspe Argentina International 7 Cape South Africa Clarke 1880 8 Carthage Tunisia Clarke 1880 9 Chatham 1971 Chatham Island New Zealand International 10 Chua Astro Paraguay International 11 Corrego Alegre Brazil International 12 European 1950 Western Europe Austria Denmark France International Federal Republic of Germany Netherlands Switzerland 13 European 1950 Cyprus International 14 European 1950 Egypt International 15 European 1950 Iran International 16 European 1950 Sicily International 17 European 1979 Austria Finland Netherlands Norway International Spain Sweden Switzerland 18 Gandajika Base Republic of Maldives International 19 Geodetic Datum 1949 New Zealand International 20 Hjorsey
52. l be initiated otherwise a Cold Start will be initiated 3 3 Navigation Mode The navigation mode is the normal operating mode of the chip set The navigation mode consists of a number of sub modes The possible sub modes are Self Initialisation or Cold Start Aided Initialisation or Warm Start Navigating 3 3 1 Self Initialisation or Cold Start Without any valid initialisation data available the receiver will enter a search mode for all available satellites Ephemeris and Almanac data from the locked satellites are decoded and loaded into RAM The Real Time Clock is updated to current UTC time obtained from the locked satellites The first navigation solution based on the initially acquired satellites at least 4 for a 3D fix is found before the Almanac Data is fully downloaded The chip set enters this mode when the whole receiver is powered on for the first time or when it receives a self initialisation command from the application System or when it detects that stored data is out of date during a Warm Start procedure for instance if the almanac data is too old 3 3 2 Aided Initialisation or Warm Start Initialisation data may be available which either resides in the receiver after previous operation or can be downloaded into the receiver from the application system The data that can aid the initialisation includes last valid position ephemeris and almanac data stored in the memory and running time stored in the RTC
53. l cause the processor to jump to the start of its programme and start code execution The following points should be noted 1 The Hardware reset is intended to be used either to wake up the processor after it has been sent to sleep or to reset the processor after the system has been switched off 2 The action of the hardware reset is to cause a Warm Start to be executed 3 The hardware reset does not reset any data to default values 3 6 2 Software Reset PHILS RST The software reset may be caused by issuing the PHILS RST command It will initialise all data defaults and then enter the Cold Start procedure The following points should be noted 1 After using the RST command the serial port speeds and all user alterable data eg such as datum DOP masks etc will be set to default values It is up to the application Host system to restore these values 2 The software reset should not be needed very often in normal application 3 6 3 Cold Start The Cold Start procedure may be started by issuing the PHILS RST C command The difference between the software reset and the Cold Start is that the Cold Start does not cause any re initialisation of data The purpose of the Cold Start is to re acquire satellites without any prior knowledge of their location it will also download the almanac The Cold Start is used when the receiver real time clock indicates that the almanac is out of date and the user does not want to input any aiding da
54. llowing sections and a typical application is provided in the schematics in Section 6 3 1 6 2 1 RAM and ROM Access The timers have been pre programmed within the system firmware to allow ROM and SRAM with access times of no more than 100 ns to be used In the recommended application memory has been implemented with an access time of 70 ns One of the memory mapped registers SYSMODE at address F0020H has one bit reserved for setting the operation of the RAM strobe Bit 15 of the SYSMODE register has a default setting of 0 which means the external RAM is always enabled To conserve power it is possible to gate the RAM enable with the RAM read strobe To gate the RAM enable with the read strobe Bit 15 of the SYSMODE register must be set to 1 In the system firmware supplied the DMCS strobe is gated with the RD signal 6 2 2 UARTS The system firmware supplied with the SAA1575 allows the baud rate to be programmed by the user between 300 to 19200 bps The default setting is 4800 bps and it is only at this speed that the NMEA outputs can be guaranteed to conform to the NMEA specification V2 01 To get RS232 levels it is necessary to use a standard RS232 interface IC such as the Maxim MAX213EAI UART1 is the default port PRTA for standard input commands and data output and UART2 is the default port PRTB for differential GPS data This is configurable by the user the details for which are outlined in Section 4 45 Philips Semicond
55. ls Single Supply OEM Board 9 lt Part Number Description C306 0603 SM Capacitor C326 0603 SM Capacitor C324 0603 SM Capacitor C344 0603 SM Capacitor C105 C106 0603 SM Capacitor 10 pF 5 C207 C208 C327 0603 SM Capacitor C348 150 pF 5 C340 0603 SM Capacitor C338 0603 SM Capacitor C309 0603 SM Capacitor C311 C312 0603 SM Capacitor 2 2 pF 5 C322 0603 SM Capacitor C205 C206 C325 0603 SM Capacitor C341 0603 SM Capacitor C210 C211 C212 C213 0603 SM Capacitor C214 C215 C216 C217 C218 C219 C220 C221 C222 C223 C224 C328 C329 C330 C331 C332 C333 C334 C336 C337 C346 1 39 pF C319 0603 SM Capacitor 1 4 7 pF C339 0603 SM Capacitor 2 4700 pF C342 C343 0603 SM Capacitor 2 47 pF 5 C302 C303 0603 SM Capacitor 2 6 8 pF 5 C315 C316 0603 SM Capacitor 54 Philips Semiconductors User Interface Manual for the EXACT GPS Chip Set Version 1 2 Table 11 Part Number Qty User s Manual SNA UM98008 Cost Optimised Build of Materials Single Supply OEM Board Continued Description C310 0603 SM Capacitor C317 C318 82 pF 5 C301 1 uF 16 V C345 0603 SM Capacitor 0603 SM Capacitor TANTAL A Polarised Capacitor 10 uF 6 3 V C111 TANTAL A Polarised Capacitor 22 uF 6 3 V C113 C114 47 uF 6 3 V 10 C225 C226 R205 R206 R316 R317 R318 R326 R327 TANTAL_C SM Capacitor TANTAL_C SM Capacitor 0603 SM
56. lt dy gt lt dz gt lt drotx gt lt droty gt lt drotz gt lt scale gt 4 1 9 8 Exception message query PHILQ XMG Command PHILQ XMG lt port gt Usage This command allows the last exception number to be read back Parameters lt port gt lt A B gt Response PHILR XMG lt errnum gt lt description gt see details in Appendix A 38 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 4 1 10 Frequency of Data Output All messages may be output on request using either standard or proprietary query commands The following messages will output at the receiver update interval as set by PHILS NME PER if enabled using PHILS NME ALM GGA GLL GSA GSV RMC VTG ZDA The following messages will output when an event occurs as follows XMG when an error exception occurs eg change of mode due to crossing a DOP mask MSG when an RTCM SC104 message is available 4 2 Differential GPS 4 2 1 RTCM Differential Messages The following differential GPS commands specified in RTCM SC104 Version 2 1 are supported by the chip set message number description 1 Differential GPS corrections 3 Reference Station Parameters 9 Partial Satellite Set Differential Corrections 16 Special Message 5 QUICK START GUIDE Hardware and software is available which allows full evaluation of the chip set The following items are supplied as part of
57. meters PHILQ PAR Command PHILQ PAR Usage Returns a set of strings showing the parameter settings of the EXACT Not NMEA compatible format Parameters None Response This response is not in NMEA format It is formatted in a way suitable for display directly on a standard terminal An example is shown here PMD 3 FIX 0 PEM 05 PDP 06 HDP 04 VDP 04 DIM W84 LTZ 00 00 SAV N USE YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY CDS AUTO LAT 0000 000000 N LON 00000 000000 E ALT 00000 00 NMEA ALM GGA GLL GSA GSV MSG POS RMC SAT VTG ZDA XMG PRTA ON ON PER 001 0 return description related command range parameters PMD Navigation Position mode PHILS PMD 0 3 FIX Altitude fix mode PHILS FIX 0 1 PEM Position elevation mask PHILS PEM 0 90 PDP PDOP mask PHILS PDP 0 99 HDP HDOP mask PHILS HDP 0 99 VDP VDOP mask fixed at 04 DTM Select datum PHILS DTM W84 USR Local Time zone PHILS LTZ 13 59 13 59 SAV Save parameters PHILS SAV Y N USE Use satellite PHILS USE Y N for each satellite CDS Not used LAT Latitude of the antenna position PHILS POS 0 90 N S LON Longitude of the antenna position PHILS POS 0 180 E W ALT Ellipsoidal height of the antenna PHILS ALT 0 99999 99 NMEA PRTA NMEA message type for output Output to port PRTB A B period if enabled or disabled PHILS NME Message enabled 0 999 Message disabled PER NMEA message output
58. mode 3 3 3 3 Mode 2 fixed 2D In this mode the receiver will always calculate a 2D position The altitude is always held constant and the value used depends upon the interaction of the PHILS ALT and PHILS FIX commands section 4 1 8 If there are fewer than three satellites available or HDOP exceeds the mask then no navigation solution shall be calculated and an error message shall indicate this Note This mode should be used with care because any error in the user s estimate of altitude will cause a similar error in the 2D position 3 3 3 4 Mode 3 automatic This is the default navigation mode At least three satellites with elevation angle equal to or above the position elevation mask are needed to compute a position If only three satellites are locked the latitude and longitude are computed and the altitude is held If more than three satellites are locked and the HDOP is less than the specified HDOP mask all three polar components are computed If HDOP is higher than the specified HDOP mask the receiver automatically goes into the altitude hold mode 3 3 3 5 UTC time In all the above modes the receiver will calculate time and output 1 PPS The first antenna position that is obtained when there are four or more satellites and HDOP and VDOP are both less than their respective mask settings will be used The 1 PPS output is a positive going 1ms pulse which has been set in firmware This output is within 250 ns of UTC
59. n base and remote Defined as number of good measurements total number of messages x 100 OFFSET Displays the number of bits from the beginning of the RTCM byte in case of a bit slippage MODE 4 Displays differential mode either remote REM or disabled OFF PORT Displays the port used to receive RTCM corrections AUT Displays auto differential mode 37 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 MAX The maximum age in seconds allowed for a message to be used to compute a 0 3599 differentially corrected position MSG Displays message up to 90 characters received from base station 4 1 9 7 User defined datum query PHILQ UDD Command PHILQ UDD lt port gt Usage This command causes the output of the user defined datum parameters message on lt port gt Parameters port 2 lt A B gt Parameters parameter range meaning lt 6300000 0 6400000 0 gt Semi major axis m lt 290 0 310 0 gt Flattening m lt gt lt 0 0 1000 0 gt Translation in x direction m lt gt lt 0 0 1000 0 gt Translation in direction lt gt lt 0 0 1000 0 gt Translation in z direction Rotation in x axis radians 0 0 lt drotz gt Rotation in z axis radians lt scale gt 0 0 Scale factor Response PHILS UDD 0 lt da gt lt df gt lt dx gt
60. nt content Save As save current content as Exit exit the edit window Tools Send Current Message send the current message line Send All Messages send all the messages displayed Ports COM x allocate isolate the edit window to COM x Re check All Ports re check all ports to provide an updated list of available ports Messages create a commonly used messages window Help call the on line help Edit NMEA Messages ne Eile Tools Ports Messages Help Messages for GPS DisebledGPSinpt Disable dGPS Input Ennblc dGPS Input Fort B Reset Recelver For Cold Start Reset Receiver For Warm Start Reset Recelver Far Hat Start B Set Message Update Interval Ta 1 Sec Set Message Update Interval Ta 10 Secs Fixed 2D Position Mode Figure8 NMEA Edit Window with Commonly Used Messages Box Open 60 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 7 3 Incoming Messages Window The incoming messages window displays all the messages coming through the selected port A filter was designed to let the user select certain types of messages to display or hide IncmingNMEAMessags FIA Tools Ports Eilters Help Figure9 Incoming Messages Window Table 15 Menu Function for the Incoming Messages Window Menu Options Description Tools Exit exit the incoming messages window Ports COM x allocate isolate the incoming messages window
61. o the reference oscillator signal It is critical that the associated digital supply VCCDIG on pin 33 is isolated and separately decoupled from all other analogue supplies This is particularly important with respect to the analogue supply VCCLIM on pin 31 44 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 6 1 5 Programming the RF IC A 3 wire interface is available on the UAA1570 allowing both the frequency divider registers to be programmed as well as allowing the device to be powered down to conserve power The 3 wire interface consists of a clock and data line as well as a latch enable Data is clocked in serially on the rising edge of the clock output RFCLK For more details on the programming of the UAA1570 refer to the baseband IC SAA1575 data sheet 6 2 Baseband IC SAA1575 The SAA1575 accepts a one or two bit IF data from an RF front end IC such as the UAA1570 and provides NMEA compatible GPS position and time information It contains eight parallel correlators allowing up to eight satellites to be tracked at any one time When used with an appropriate RF IC such as the UAA1570 the only external components required are RAM firmware ROM and crystals for the system clock and real time clock RTC More detailed information on the features of the SAA1575 can be found in the data sheet Reference 7 Some of the main application issues are covered in the fo
62. of precision in a computation due to bad satellite geometry DRAM Dynamic RAM ECEF Earth Centred Earth Fixed EEPROM Electrically Erasable Programmable ROM Philips Semiconductors User Interface Manual for the EXACT GPS Chip Set Elevation Elevation Mask EPROM EXACT GPS HDOP IC Icc Image Rejection L1 LNA Mask Navigation solution NMEA0183 Noise Figure PPS PRN RAM RF RF Sensitivity ROM RTC RTCM SC104 UAA1570 SAA1575 Signal Strength Spurious SV TTFF UART Update Rate UTC VCC VDOP VSWR WGS 84 User s Manual Version 1 2 SNA UM98008 Angle above the horizon in degrees Elevation angle above which satellites will be used in navigation computation Electrically Programmable ROM England XA Ashtech CPG Technology Global Positioning System Horizontal Dilution of Precision Integrated Circuit Current supplied to the positive terminal of a circuit The attenuation of the image frequency in a mixing process Input Output The frequency band for civil GPS signals centred on 1575 42 MHz Low Noise Amplifier A programmable threshold value above or below which data will not be used High level software to compute the position from received satellite data Standard for transmitting receiving navigation information The additional noise added by a circuit over and above that due to the input noise Pulse per second Pseudo Random Noise ie the unique spreading code
63. of selected NMEA or Raw data to port at update rate except for SAL which will be output once per hour if enabled Parameters lt string gt lt ALM GGA GLL GRS GSA GSV GXP RMC VTG ZDA MSG SAL ALL gt port lt A B gt Port on which to see messages bool lt ON QFF gt Enable or Disable message reporting per lt 1 999 0 gt Update interval Default is 1 second The strings used indicate the following NMEA standard messages ALM GPS Almanac GGA Position fix GLL Geographic latitude longitude GSA GPS DOP and active satellites GSV GPS Satellites in View RMC Recommended Minimum Specific GPS Data VTG Course over ground and ground speed ZDA Time and Date Non standard NMEA format messages MSG Differential Message RTCM SC104 types 1 3 9 and 16 Proprietary Message XMG Exception messages ALL All the above messages Response ACK NAK 4 1 8 8 Receiver update interval PHILS NME PER Command PHILS NME PER lt 1 999 gt Usage The receiver will output requested data at the update interval specified The use of longer intervals will conserve power Parameters 1 Output once per second 999 Output once per 999 seconds Response ACK NAK 4 1 8 9 Mask PDOP PHILS PDP Command PHILS PDP lt value gt Usage Set the Position Dilution of Precision mask If the PDOP mask is exceeded no navigation solution will be output Parameters value lt 0 99 gt Default 6 Response ACK NAK 29 Philips
64. ous dilution of precision masks are exceeded These are described in Appendix A When EXACT enters the Set Defaults state due to a software reset PHILS RST the pin GPIOO will be asserted to inform the host processor This is because communication may be lost as the UARTs will be returned to their default baud rates 3 5 1 Priority of Interrupt Sources A priority handler block decides which is the highest priority of the possible sources of interrupt These are as follows highest RESET BIT RST Cold Start Notes 1 A RESET can be caused by a hardware RESET using PWR_FAIL and PWR_DN on the baseband processor 2 RST is a software reset to defaults caused by the PHILS RST command 17 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 3 6 System Initialisation This section describes the difference between the different ways of initialising and or resetting the EXACT chip set There are a number of related issues 1 Hardware reset using the RESET pins PWR_FAIL and PWR_DN 2 Software reset using the command PHILS RST 3 Cold Start using the command PHILS RST C 4 Warm Start using the command PHILS RST W 5 Hot Start using the command PHILS RST H 6 Initialisation data using the command PHILS POS and PHILS ZDA 3 6 1 Hardware Reset The hardware reset may be caused by the RESET pins of the baseband processor IC The hardware reset wil
65. pes of application windows The Host Software uses the following COM Port settings 4800 Baud 8 Data Bits 1 Stop Bit and no parity It is important that the receiver under test is set at the default baud rate of 4800 for this software to work correctly Window stalus Windi Figure 6 Basic Structure of EXACT Host Software 7 1 Desktop Window The desktop window is the top level control window it is used to create application windows as well as log files When the Host software is executed the desktop window defaults to the following state Three sub windows Incoming NMEA Messages Receiver Position Window and Satellite Position Window are opened and scaled appropriately In the bottom left corner of the screen are three iconised sub windows Edit NMEA Messages Receiver Motion and Status The iconised windows can be opened by double clicking on them using the mouse Table 13 on Page 59 outlines the various options available from within the Desktop Window 58 Philips Semiconductors User Interface Manual for the EXACT GPS Chip Set User s Manual SNA UM98008 Version 1 2 Tesis Ports Eihers Help Receiver Posie fools Peis Help Incaming 2 Satellite Posten Help Figure 7 Desktop Window Table 13 Menu Functions of the Desktop Window Menu Options Description File Create Log create a log file Associate associate a log file
66. pplication information for the Philips GPS chip set EXACT EXACT is a two chip solution comprising a front end RF IC UAA1570 and a baseband processing IC SAA1575 The SAA1575 is supplied with production ready software to provide a complete system solution for computing and outputting NMEA compatible position information A detailed description of all user commands is provided together with design guidelines and schematic diagrams A simple guide to getting started is provided in Section 5 This section provides the user with all the information to get up and running quickly with the demonstration system Philips Semiconductors User Interface Manual for the EXACT GPS Chip Set Version 1 2 Table of Contents 1 INTRODUCTION 1 1 Glossary 1 2 Features 2 SPECIFICATIONS OF THE CHIP SET AND SOFTWARE 2 1 Navigation Specifications 2 1 1 Controller Functionality 2 2 Electrical Specifications 2 3 RF Specifications 3 MODES OF OPERATION 3 1 Off Mode 3 2 Sleep Mode 3 3 Navigation Mode 3 3 1 Self Initialisation or Cold Start 3 3 2 Aided Initialisation or Warm Start 3 3 3 Navigating 3 3 3 1 Mode 0 fixed 3D 3 3 3 2 Mode 1 three satellite 3 3 3 3 Mode 2 fixed 2D 3 3 3 4 3 automatic 3 3 3 5 UTC time 3 4 BIT Mode 3 5 Mode Transitions 3 5 1 Priority of Interrupt Sources 3 6 System Initialisation 3 6 1 Hardware Reset 3 6 2 Software Reset PHILS RST 3 6 3 Cold Start 3 6 4 Warm Start 3 6 5 Hot Start 3 6 6 Initialisation Dat
67. rential Data Age Selection 60 seconds PHILS RTC MAX Serial Port A speed 4 corresponds to 4800 bps PHILS SPD Serial Port B speed 4 corresponds to 4800 bps PHILS SPD Altitude Position Fix Mode 0 PHILS FIX Time zone offset 00 00 PHILS LTZ Enable ALM msg to port at rate A OFF PHILS NME ALM Enable GGA msg to port atrate A OFF PHILS NME GGA Enable GLL msg to port at rate A OFF PHILS NME GLL Enable GSA msg to port at rate A OFF PHILS NME GSA Enable GSV msg to port at rate A OFF PHILS NME GSV Enable RMC msg to port at rate A OFF PHILS NME RMC Enable VTG msg to port at rate A OFF PHILS NME VTG Enable ZDA msg to port at rate A OFF PHILS NME ZDA Enable MSG msg to port at rate A OFF PHILS NME MSG Exception message to port A ON PHILS NME XMG Receiver update interval 1 second PHILS NME PER
68. rogrammable DOP Masks Standard serial I O TiS 100 101 7 SAA1575 UART1 PWR FAIL PWR DN UARTO Figure 1 Simplified Block Diagram The software provided defaults to selected values to optimize performance but each parameter is user programmable 11 Philips Semiconductors User Interface Manual for the EXACT GPS Chip Set User s Manual Version 1 2 SNA UM98008 2 SPECIFICATIONS OF THE CHIP SET AND SOFTWARE This section describes the chip set specifications in three sections navigation electrical excluding RF and RF specifications 2 1 Navigation Specifications L1 frequency 1575 42 MHz C A code Receiver Number of Channels 8 parallel channels tracking up to 8 satellites at the same time Output data Position Velocity Time 1 PPS Pulse Per Second Satellite information Receiver Status NMEA 0183 Protocol messages Input data Receiver function commands DGPS data in RTCM SC104 format Position Accuracy Assuming 95 probability the position accuracy can be as shown in Table 1 The figures provided are defined in terms of horizontal circular error probable and not 2dRMS Table 1 Position Accuracy of EXACT Unit Metres DGPS Satellite SA Horizontal Max Vertical Max 3D Max ON ON 10 15 9 8 ON OFF 5 9 5 9 8 OFF ON 100 156 174 OFF OFF 25 46 49 Velocity Accuracy 0 2 kilometres hour with SA off Note Accuracies quoted relative
69. rs all receiver memory An acknowledgment will be received which can be cleared by clicking on OK or pressing return on the keyboard Within the Incoming NMEA Messages an acknowledge will appear PHILR ACK 2A Click on the Messages menu within the Edit NMEA Messages window Another window opens that allows specific messages to be selected and sent by the user without typing the appropriate command This list of messages may be accessed by clicking on the arrow icon on the right hand side Select from the menu Enable All NMEA Messages on and then click on Send to transmit the command On the Incoming NMEA Messages window a series of acknowledges will be received PHILR ACK 2A indicating a successful transmission At this point a stream of all available NMEA messages will be output on the Incoming NMEA Messages window at an update rate of 1 second Once a valid position is obtained typically within 5 minutes position and satellite data will begin to be displayed on the appropriate windows For more detail on what each individual window supports and how to log incoming data please refer to Section 7 of this manual Note The various windows can only be guaranteed to work when all NMEA messages are enabled 5 4 Aiding Initial Acquisition When the receiver is first powered up no data is stored to aid the acquisition process To improve the acquisition time the approximate time and position can be easily entered into the receiver
70. sed always 0 0 lt drotz gt 0 0 Not used always 0 0 lt scale gt 0 0 Not used always 0 0 Response ACK NAK 4 1 8 25 Upload initial real time clock value PHILS ZDA Command PHILS ZDA lt rtc gt Usage Allows data to be loaded into the Real Time Clock store of the receiver This is used during aided initialisation and should be used if it is known that the data available to the receiver is invalid Parameters parameter range meaning rtc Data in the format of the NMEA GPZDA sentence refer to NMEA 0183 V2 01 ie PHILS ZDA 123030 00 01 01 1998 Note The UTC time zone field must be null Any other value will generate a NAK response In normal usage this command should not be needed However it can be used in cases where it is known that the clock data is significantly different as it will speed up acquisition of the satellites Response ACK NAK 34 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 4 1 9 Description of Query Commands There are two types of query commands proprietary and NMEA All queries may be made using the PHILQ header The query commands are described below 4 1 9 1 NMEA message query PHILQ lt message gt Command PHILQ lt message gt lt port gt Usage Used to read back a standard or non standard NMEA format message from the system Parameters lt message gt lt ALM GGA GLL GSA GSV
71. ta 18 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 3 6 4 Warm Start The Warm Start procedure will be started automatically whenever the software detects that the almanac position or real time clock have changed Hence a Warm Start can occur as a result of the initialisation command PHILS POS A Warm Start can also be started by issuing the PHILS RST W command Under these conditions valid almanac data and approximate position is available to the receiver If upon a Warm Start the SRAM corrupted exception occurs then the application Host software must re initialise certain data eg datum port speeds etc When SRAM is corrupted the general purpose IO pin 0 GPIOO on the baseband chip will be asserted This is because the serial interface will be restored to the default data rate which may not be the rate at which the host processor is operating 3 6 5 Hot Start The Hot Start procedure occurs when valid almanac and ephemeris data is available and that the approximate receiver position and time is known This procedure would be typical of a receiver that had been powered down for a couple of hours prior to use This procedure can be started by issuing the command PHILS RST H 3 6 6 Initialisation Data The initialisation data commands PHILS POS and PHILS ZDA are used to help speed up acquisition It allows the almanac data position and real time clock
72. the Starter Kit Evaluation Board GPS Antenna Mitsubishi VIC 1 Type Power Cableform with 4 mm banana plugs DC Supply 6 17 V Power Cableform with universal car adaptor for in car use Interface cable for connecting hardware to PC Com port 9 way D Type PC Host Software Package Data Sheets for the Chip Set RF UAA1570 and Baseband SAA1575 User Interface Manual PCB Gerber Files All on 1 x 3 5 inch Floppy Disk 39 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 5 1 Hardware Setup The evaluation board can be connected to a PC running under a 16 bit Windows environment of 3 1 or above and ideally the processor running at a minimum of 100 MHz A 9 way female to female D Type cable is provided allowing connection to a suitable PC Com port The board is powered at PL101 between 6 and 17 V Two cables are provided allowing connection to a standard bench power supply or alternatively to a standard car adaptor to allow field testing A female SMA connector is provided J301 to connect a suitable antenna The board is designed to provide 5V 1096 at 25 mA at the antenna input to drive an active antenna 5 2 PC Software Installation A 3 5 inch floppy disk is provided containing a Windows evaluation software This provides the user with all status information related to the receiver and allows quick and easy high level evaluation of the board
73. the external SRAM and to the on chip Real Time Clock via the Real Time Clock power pin For instance a lithium backup battery could be used to power the real time clock and the external SRAM In this case the power consumption will be very low approximately 30 uW at 3V To re start the system the power should be applied to the chip set and a RESET applied The system will then use the stored almanac in the external SRAM and the Real Time Clock to search for the satellites and generate a fix Itis up to the user to supply the setup data for instance port assignments etc which will have been lost as power has been removed from the main chip It is possible that the Almanac and Real Time Clock have become corrupted In this case the system will generate an exception message to warn the host processor and then enter a Cold Start A Cold Start may be aided by sending for instance user defined time and position data from the host processor which will speed up the acquisition process 14 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 3 2 Sleep Mode In Sleep mode the power may be maintained on the chip set the external SRAM and the Real Time Clock The chip set may be woken up by applying a hardware RESET or any input to the serial ports When reset is applied the internal software will examine the internal memory for corruption If the data is OK a Warm Start wil
74. there own risk and agree to fully indemnify Philips Semiconductors and Philips Electronics North America Corporation for any damages resulting from such improper use or sale Purchase of Philips 2 components conveys a license under the Philips I C patent to use the components in the I C system provided the system conforms to the IC specifications defined by Philips Philips Electronics NV 1998 All rights are reserved Reproduction in whole or in part is prohibited without the prior written consent of the copyright owner The information presented in this document does not form part of any quotation is believed to be accurate and reliable and may be changed without notice No liability will be accepted by the publisher for any consequence of its use Publication thereof does not convey nor imply any license under patent or other industrial or intellectual property rights 2 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 USER S MANUAL SNA UM98008 User Interface Manual for the EXACT GPS Chip Set Version 1 2 Author s M Thorne Philips Semiconductors Systems Laboratory Southampton England Keywords GPS EXACT satellite command PHILS Date 29 June 1998 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 Preface This document provides all user interface and a
75. time in differential mode and within 1 us of UTC time without differential mode 16 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 3 4 BIT Mode The Built In Test mode BIT allows the system to check itself and report back results to the host The BIT routine can be programmed to carry out some or all of the following test procedures Memory test Volatile memory test Non volatile memory test Commands and responses of the BIT procedure are described in the receiver I O protocol Section 4 1 9 2 on Page 35 3 5 Mode Transitions The Warm Start state is used to determine if the data preserved in SRAM is corrupted by doing a Checksum If this Checksum fails the Cold Start state is entered Various exceptions are issued as follows Table3 Mode Transitions from Power Up Exception No Description Meaning 1 SRAM corrupted System will enter Set Defaults state due to lost data 2 RTC corrupted System will enter Cold Start state due to loss of time information 3 Invalid Data System will enter Cold Start state due to data too old BIT completed End of built in test routines Note The application system may respond to exception 2 or 3 by programming initialisation data using PHILS POS and PHILS ZDA which will then result in a Warm Start Other exceptions will be generated during navigation mode as satellites go in and out of view and as the vari
76. to COM x Re check All Ports re check all ports to provide an updated list of available ports Filters ALM etc display hide the ALM messages etc All display hide all messages call on line help 61 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 7 4 Satellite Position Window The satellite position window displays the satellite position and status The position is displayed in polar graphical format and the signal strength in forms of bar graphics Individual information windows for each satellite can also be created by clicking on a satellite in the grid Figure 10 The resultant window will provide azimuth elevation and Signal to Noise Ratio SNR of that particular satellite Table 16 Menu Functions for Satellite Position Window Menu Options Description Tools exit the window Ports allocate isolate COM x to the window Re check All Ports re check all ports to provide an updated list of available ports Help B call on line help Satellite Position Tools Ports Help 4 Figure 10 Satellite Position Window 62 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 7 5 Receiver Position Window The receiver position window displays the position fix information
77. to SA are dependent on the parameters of the GPS system and hence cannot be guaranteed Time Synchronized to UTC within 1 us typically Navigation Solution Update rate 1 second standard 2 999 integer seconds as option Time pulse output 1 Pulse Per Second PPS with accuracy of 250 ns in differential mode and 1 us without differential Acquisition Rate Time To First Fix 12 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 Table 2 Acquisition Time To First Fix Valid Data Time To First Fix secs Mode iti Start Almanac Ephemeris Typical lt 7 days old lt 4 hours old Results As well as typical acquisition times the 50 and 90 percentile specs are provided ie in the case of a goth percentile in 90 out of 100 experiments a valid position is calculated within this time Note that Warm Start Hot Start and Cold Start acquisition time excludes the time required to download any initialisation information eg almanac position or current time Re acquisition Re acquisition shall be defined as the time between the end of the signal blockage and the time three or more satellites are tracked and a valid position calculated For re acquisition the receiver has valid almanac ephemeris and time together with an approximate position The times stated are 50 percentiles Interruption of 10 seconds Re acquisition 2 seconds
78. uctors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 6 2 3 Power Up and Reset Procedure In order to guarantee a successful reset of the baseband IC the following procedure must be followed very carefully There are three inputs DN PWR FAIL and RSTIME that control the reset of the device Voltage reference devices are normally used derived from the main supply voltage PVcc For example if a 5 V supply was used DN may be input to the SAA1575 from a 4 8 V reference and PWR FAIL may be input from a 4 6 V reference device To successfully reset the IC PWR FAIL must go high before PWR DN and the core supply CVcc must be above 2 7 V before either edge occurs The following sequence must be followed CVcc above 2 7 V PWR FAIL goes from low to high PWR DN goes from low to high At this point the IC remains in reset for a period of time controlled by the level of RSTIME If RSTIME is high reset is de asserted 10 ms after PWR DN goes high If RSTIME is low then reset is de asserted 10 us after PWR DN goes high It is recommended that RSTIME is only held low when the system clock is being derived from an external clock source 6 2 4 Power Down and Battery Backup Battery backup control is contained on board the SAA1575 to simplify the application Two outputs PWRB and PWRM are driven directly from the input FAIL Using voltage reference devices for PWR FAIL and PWR DN allo
79. ws safe power down without corrupting SRAM The following sequence should be followed and is incorporated in the system firmware provided Main supply PVcc starts to fall PWR DN goes from high to low Parameters saved to RAM and memory transfers halted PWR FAIL goes from high to low forcing IC into reset As PWR FAIL goes low PWRM goes high and PWRB goes low switching power over to the battery supply At this point both the core and periphery supplies are driven from the battery allowing the real time clock to continue running and all parameters in RAM to be maintained In this mode in a typical application the power consumption of the system would be approximately 10 uA at 3 0 V 6 3 PCB Description This section provides the schematics for the EXACT evaluation board This is intended to provide a typical application for the chip set A parts list for the evaluation board is also available in Table 10 on Page 51 46 User s Manual Philips Semiconductors SNA UM98008 User Interface Manual for the EXACT GPS Chip Set Version 1 2 6 3 1 Schematic Diagrams POWER SUPPLY DIGITAL PROCESSOR RF FRONT END ower sch baseband sch rf front sch Number 801291 1 Title GPS DEMO BOARD Revision 1 3 GPS Demo Board Figure 2 47 Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 GPS
80. ype Female SMA Connector 3 V 170 mAh Lithium Battery 3 V 5V JP201 PL101 Jumper Select 3 V 5 V for U301 10 Way Test Header Jumper and Power Connector C304 C305 C307 C308 C347 L309 R208 R209 R210 R309 R324 53 Items not fitted on the PCB Philips Semiconductors User Interface Manual User s Manual for the EXACT GPS Chip Set Version 1 2 SNA UM98008 6 3 3 Board Costing Consiiderations When evaluating the cost of the Philips GPS chipset solution it is important to compare against a typical OEM GPS engine In this case it is usually a small board running from a single supply with no RS232 driver on board The materials list in Table 11 provides a list of the components required to produce a typical OEM board Table 12 on Page 57 provides a comparison of the relative component count for each board to simplify the costing evaluation The demonstration board has not been optimised for cost and contains a number of power regulators as well as an RS232 driver and its associated D Type connectors In practice it is more typical to provide a single connector for the power and communications and to run the GPS module from a single supply voltage This comparison assumes a 5 V system with no onboard RS232 drivers for the serial ports One of the band pass filters at the front end has also been removed assuming the system is used with an active antenna with around 26 dB gain Table 11 Cost Optimised Build of Materia

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