Kenwood NXR-700 Service Manual

Also see for NEXEDGE NXR-700: Brochure Instruction manual Instruction manual Instruction manual Instruction manual

Contents

NXR-70047■ Start-up of each Control Block• Main MPU BlockComponent elements:· Main MPU: IC703· Flash Memory: IC702· SD RAM: IC704 and IC707· LAN IC: IC719· RTC: IC701Overview of Start-up Operation:When MPU reset line logic switches as high, the MPUstarts reading the program from the flash memory andexpands the program to SDRAM. Linux OS begins opera-tion on the SDRAM after main MPU transfers the program.Main MPU works usage of Linux OS codes. The otherhigher-level applications software to the Linux OS will alsobe expanded in SDRAM. On starting up, main MPU verifythe status of the registers in LAN IC except SDRAM whichis purpose of backup data even if abnormal symptom de-tects in either LAN IC or SDRAM, the start-up process isnot affected by this error; main MPU behaves operation asif it works properly. To express another word, either Flashmemory or SDRAM has defective, a circuit behaves as ifmain MPU happens malfunction. After executing all ini-tialization routines, the Main MPU verifies the operationalstatus of each MPU then transmits/ receives the operationtransfer command set to from the Modem control MPU(IC325) and the RF control MPU (IC34) using 115.2kbpsUART communications.• RF Control MPU BlockComponent elements:· RF control MPU: IC34· Flash memory: IC17· DSP: IC37Overview of Start-up Operation:When the RF control MPU (IC34) reset line logic switchesas high, this MPU reads the boot program from the internalROM of MPU and then initializes the peripheral devices.After this boot process completes, the MPU starts work-ing with the programs (application programs) stored in flashmemory (IC17) to process the preprogrammed tasks. Dur-ing the process, the MPU transfers the program to the DSPIC (IC37). It also verifies the operating status of DSP at cer-tain interval.After a series of processes completes, the RF controlMPU verifi es the operational status and then transmits andreceives the operation transfer command set to/from MainMPU (IC703) using 115200bps UART communications.• Modem Control MPU BlockComponent elements:· Modem control MPU: IC325· Flash memory: IC314· RX DSP: IC323· TS Vocoder DSP: IC324Overview of Start-up OperationWhen the Modem control MPU (IC325) reset line logicswitches as high, the MPU reads the boot program from theinternal ROM of MPU and then initializes the peripheral de-vices. After this boot-up process completes, the MPU startsworking with the programs (application programs) stored inflash memory (IC314) to process the preprogrammed tasks.During the process, the MPU transfers the program to theRX DSP IC (IC323) and TX Vocoder DSP IC (IC324). It alsoconfirms the operating status of these DSP ICs. After a se-ries of processes completes, the Modem control MPU con-firms the operational status and then transmits and receivesthe operation transfer command set to/from Main MPU(IC703) using 115200 bps UART communications.• Possible Symptoms if the Block (mainly BGA IC)MalfunctionsRef. No. Element ofBlock Presumption SymptomsIC703 Main MPU• Since the boot program cannot be executedat all, the LEDs do not light or fl ash.• The operations that should be executed byIC703 are not processed.• Runaway of IC703.IC17FlashMemoryon RF con-trol MPUblock• Migrated to the programming mode (Write).(“PG” appears on the 17-segment LEDdisplay.)• The operations that should be executed byIC34 are not processed.• Runaway of IC34.IC314FlashMemoryon Modemcontrolblock• Migrated to the programming mode (Write).(“PG” appears on the 17-segment LEDdisplay.)• The operations that should be executed byIC325 are not processed.• Runaway of IC325.IC323 RX DSP• While the boot program is executed, theoperation stops (the status LED is fl ashing).• The operations that should be executed byIC323 are not processed.• Runaway of IC323.IC324TXVocoderDSP• While the boot program is executed, theoperation stops (the status LED is fl ashing).• The operations that should be executed byIC324 are not processed.• Runaway of IC324.TROUBLE SHOOTING