Theory of Operation
: Global Positioning Sytem (GPS)
3-53
3.2.7.5 Key Zeroize
The encryption keys can also be manually erased if infinite key retention is not turned on in
codeplug, by holding down the Side Top button and emergency buttons during radio power-up.
These two button inputs both connect to a dual transistor Q2537, which will release the
Key_ZEROIZE signal sensed by MACE's TPR0 (U2510-M2). Once this condition is sensed (floating
high), the encryption keys will be erased.
To troubleshoot the encryption circuitry, refer to the flowcharts in
Chapter 5 “Troubleshooting Charts”
.
3.3
Global Positioning Sytem (GPS)
The APX 2000/ APX 4000 GPS architecture employs the Texas Instruments NL5500 GPS IC
(U1301) (located on the Main Board) which decodes GPS signals at 1575.42 MHz (L1 band). It is
capable of producing a final position solution including full tracking and data decode capability. The
GPS signal is received by the main RF/GPS combination antenna. The GPS signal is then diplexed
at the antenna port via a series resonant network, C1315 and L1316 which provides a very low
capacitive load to the transceiver. Additional GPS diplexing components include L1117 and C1122
which provide proper termination at the transceiver path output to minimize GPS signal leakage at
the antenna port tap point at C1314. The GPS signal will then go through a SAW filter (FL1301), LNA
(U1304), and a second SAW filter (FL1303), which then connects to the NL5500’s GPS RF input
(U1301 pin L2). The NL5500 IC is connected to the main OMAP processor via UART2. It is a two
wire UART interface (TX and RX with no handshaking).
The GPS receiver is setup in an autonomous continuous navigation mode where the current position
is updated once per second. The GPS receiver continuously tracks satellites for as long as the radio
is powered on to ensure the best possible accuracy. In the event the radio loses visibility of the
satellites due to terrain or environmental factors such as driving through a tunnel or entering a
building, the GPS will temporarily lose its position fix. If the signal outage is long enough, a power
savings algorithm will then cycle the GPS in and out of a sleep mode to save battery life until the
radio has moved back into an environment where the GPS signal is present.
The following table lists the power, clock, and I/O connections from the GPS IC to various
peripherals.
Содержание APX 2000
Страница 1: ...APXTM TWO WAY RADIOS APX 1000 APX 2000 APX 4000 APX 4000Li DETAILED SERVICE MANUAL ...
Страница 4: ......
Страница 6: ...iv Document History Notes ...
Страница 8: ...Notes vi Commercial Warranty ...
Страница 10: ...Notes ...
Страница 22: ...xiv List of Figures Notes ...
Страница 165: ...Troubleshooting Waveforms Clocks 6 3 6 2 2 4 MHz Clock Trace 1 Trace recorded at R6113 Figure 6 2 4 MHz Clock Waveform ...
Страница 172: ...6 10 Troubleshooting Waveforms Audio SSI 6 3 4 BCLK Trace 1 Trace recorded at R6107 Figure 6 9 Audio SSI BCLK Waveform ...
Страница 174: ...6 12 Troubleshooting Waveforms RX SSI 6 4 2 DA Trace 1 Trace recorded at R2805 Figure 6 11 RX SSI DA Waveform ...
Страница 175: ...Troubleshooting Waveforms RX SSI 6 13 6 4 3 FSYNC Trace 1 Trace recorded at R2804 Figure 6 12 RX SSI FSync Waveform ...
Страница 177: ...Troubleshooting Waveforms TX SSI 6 15 6 5 2 DA Trace 1 Trace recorded at R2817 Figure 6 14 TX SSI DA Waveform ...
Страница 178: ...6 16 Troubleshooting Waveforms TX SSI 6 5 3 FSYNC Trace 1 Trace recorded at R2807 Figure 6 15 TX SSI FSync Waveform ...
Страница 179: ...Troubleshooting Waveforms SPI 6 17 6 6 SPI 6 6 1 CLK Trace 1 Trace recorded at R2803 Figure 6 16 SPI CLK Waveform ...
Страница 180: ...6 18 Troubleshooting Waveforms SPI 6 6 2 CS Trace 1 Trace recorded at R6602 Figure 6 17 CS Waveform ...
Страница 182: ...6 20 Troubleshooting Waveforms I2C BUS 6 7 2 SCL 5V Trace 1 Trace recorded at R2204 Figure 6 19 I2C Bus SCA 5V Waveform ...
Страница 183: ...Troubleshooting Waveforms I2C BUS 6 21 6 7 3 SDA Trace 1 Trace recorded at R6209 Figure 6 20 I2C Bus SDA Waveform ...
Страница 187: ...Troubleshooting Waveforms USB 6 25 6 10 USB 6 10 1 D Trace 1 Trace recorded at TP F_GCAI_USB Figure 6 24 USB D Waveform ...
Страница 188: ...6 26 Troubleshooting Waveforms USB 6 10 2 D Trace 1 Trace recorded at TP F_GCAI_USB Figure 6 25 USB D Waveform ...
Страница 190: ...6 28 Troubleshooting Waveforms SDRAM 6 11 2 CLKX Trace 1 Trace recorded at TP6308 Figure 6 27 SDRAM CLKX Waveform ...
Страница 226: ...6 64 Troubleshooting Waveforms LF CW on Spectrum Analyzer Notes ...
Страница 284: ...8 4 Schematics Boards Overlays and Parts Lists List of Transceiver Schematics and Board Overlays Notes ...
Страница 688: ...Index 4 Index Notes ...
Страница 689: ...Title Page ASTRO APX 1000 Digital Portable Radios Section 2 VHF UHF1 UHF2 700 800 MHz APX 1000 ...
Страница 690: ...ii Notes ...
Страница 695: ...List of Tables xi Related Publications APX 1000 Digital Portable Radios Basic Service Manual 68012004056 ...
Страница 700: ...xvi List of Figures Notes ...
Страница 756: ...4 6 Troubleshooting Procedures Power Up Self Check Diagnostics and Repair Not for Field Use Notes ...
Страница 806: ...5 50 Troubleshooting Charts PA Failure Notes ...
Страница 809: ...Troubleshooting Waveforms Clocks 6 3 6 2 2 4 MHz Clock Trace 1 Trace recorded at R6113 Figure 6 2 4 MHz Clock Waveform ...
Страница 816: ...6 10 Troubleshooting Waveforms Audio SSI 6 3 4 BCLK Trace 1 Trace recorded at R6107 Figure 6 9 Audio SSI BCLK Waveform ...
Страница 818: ...6 12 Troubleshooting Waveforms RX SSI 6 4 2 DA Trace 1 Trace recorded at R2805 Figure 6 11 RX SSI DA Waveform ...
Страница 819: ...Troubleshooting Waveforms RX SSI 6 13 6 4 3 FSYNC Trace 1 Trace recorded at R2804 Figure 6 12 RX SSI FSync Waveform ...
Страница 821: ...Troubleshooting Waveforms TX SSI 6 15 6 5 2 DA Trace 1 Trace recorded at R2817 Figure 6 14 TX SSI DA Waveform ...
Страница 822: ...6 16 Troubleshooting Waveforms TX SSI 6 5 3 FSYNC Trace 1 Trace recorded at R2807 Figure 6 15 TX SSI FSync Waveform ...
Страница 823: ...Troubleshooting Waveforms SPI 6 17 6 6 SPI 6 6 1 CLK Trace 1 Trace recorded at R2803 Figure 6 16 SPI CLK Waveform ...
Страница 824: ...6 18 Troubleshooting Waveforms SPI 6 6 2 CS Trace 1 Trace recorded at R6602 Figure 6 17 CS Waveform ...
Страница 826: ...6 20 Troubleshooting Waveforms I2C BUS 6 7 2 SCL 5V Trace 1 Trace recorded at R2204 Figure 6 19 I2C Bus SCA 5V Waveform ...
Страница 827: ...Troubleshooting Waveforms I2C BUS 6 21 6 7 3 SDA Trace 1 Trace recorded at R6209 Figure 6 20 I2C Bus SDA Waveform ...
Страница 831: ...Troubleshooting Waveforms USB 6 25 6 10 USB 6 10 1 D Trace 1 Trace recorded at TP F_GCAI_USB Figure 6 24 USB D Waveform ...
Страница 832: ...6 26 Troubleshooting Waveforms USB 6 10 2 D Trace 1 Trace recorded at TP F_GCAI_USB Figure 6 25 USB D Waveform ...
Страница 834: ...6 28 Troubleshooting Waveforms SDRAM 6 11 2 CLKX Trace 1 Trace recorded at TP6308 Figure 6 27 SDRAM CLKX Waveform ...
Страница 1008: ...8 178 Schematics Boards Overlays and Parts Lists Transceiver RF Boards UHF2 84012621001 Notes ...
Страница 1062: ...8 234 Schematics Boards Overlays and Parts Lists Keypad Board M2 and M3 PC000261A01 Notes ...
Страница 1063: ...Title Page ASTRO APX 1000 APX 2000 APX 4000 APX 4000 Li Digital Portable Radios Section 3 Appendices ...
Страница 1064: ...ii Notes ...
Страница 1068: ...Notes A 4 EMEA Warranty Service and Technical Support Further Assistance From Motorola ...
Страница 1072: ...B 4 LACR Replacement Parts Ordering and Motorola Service Centers Motorola Service Centers Notes ...
Страница 1090: ...Glossary 10 Glossary Notes ...
Страница 1094: ...Index 4 Index Notes ...
Страница 1095: ......