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Overview of Start-up Operation:
When the Modem control MPU (IC325) reset line logic
switches as high, the MPU reads the boot program from the
internal ROM of MPU and then initializes the peripheral de-
vices. After this boot-up process completes, the MPU starts
working with the programs (application programs) stored in
fl ash memory (IC314) to process the preprogrammed tasks.
During the process, the MPU transfers the program to the
RX DSP IC (IC323) and TX Vocoder DSP IC (IC324). It also
confi rms the operating status of these DSP ICs. After a se-
ries of processes completes, the Modem control MPU con-
fi rms the operational status and then transmits and receives
the operation transfer command set to/from Main MPU
(IC703) using 115200 bps UART communications.
• Possible Symptoms if the Block (mainly BGA IC)
Malfunctions
Element of
Ref. No.
Presumption Symptoms
Block
• Since the boot program cannot be executed
at all, the LEDs do not light or fl ash.
IC703 Main MPU
• The operations that should be executed by
IC703 are not processed.
• Runaway of IC703.
• Migrated to the programming mode (Write).
Flash
("PG" appears on the 17-segment LED
Memory
display.)
IC17
on RF con-
• The operations that should be executed by
trol MPU
IC34 are not processed.
block
• Runaway of IC34.
• Migrated to the programming mode (Write).
Flash
("PG" appears on the 17-segment LED
Memory
display.)
IC314
on Modem
• The operations that should be executed by
control
IC325 are not processed.
block
• Runaway of IC325.
• While the boot program is executed, the
operation stops (the status LED is fl ashing).
IC323 RX DSP
• The operations that should be executed by
IC323 are not processed.
• Runaway of IC323.
• While the boot program is executed, the
TX
operation stops (the status LED is fl ashing).
IC324
Vocoder
• The operations that should be executed by
DSP
IC324 are not processed.
• Runaway of IC324.
TROUBLE SHOOTING /
故障排除
启动操作概述 :
当调制解调器控制 M P U ( I C325) 复位线路逻辑转换为高时，
该 M P U 将从 M P U 的内部 R O M 读取引导程序，然后初始化外围
设备。完成该引导过程后，MPU 将以闪存 (IC314) 内储存的程
序 ( 应用程序 ) 开始工作，对编程的任务进行处理。
处理过程中，MPU 将程序传送到 RX DSP IC(IC323) 和 TX
声码器 DSP IC(IC324)。此外，它还确认这些 DSP IC 的运行
状态。一系列过程完成后，调制解调器控制 M P U 将确认运行
状态，然后利用 115200 bps UART 通信发送 / 接收发到 / 来
自主 MPU(IC703) 的操作传送指令集。
• 区块 ( 主要是 BGA IC) 发生故障时可能存在的现象
有关号
区块元件
码
• 由于引导程序根本无法执行，LED 不点亮
或闪烁。
IC703 主 MPU
• 应由 IC703 执行的操作无法得到处理。
• IC703 失控。
• 转移到编程模式 ( 写入 )。(17 段 LED 显
RF 控制
示上出现"PG" 。)
IC17
MPU 块上
• 应由 IC34 执行的操作无法得到处理。
的闪存
• IC34 失控。
• 转移到编程模式 ( 写入 )。(17 段 LED 显
调制解调
示上出现"PG" 。)
IC314
器控制块
• 应由 IC325 执行的操作无法得到处理。
上的闪存
• IC325 失控。
• 执行引导程序时，操作停止 ( 状态 LED 闪
烁 )。
IC323 RX DSP
• 应由 IC323 执行的操作无法得到处理。
• IC323 失控。
• 执行引导程序时，操作停止 ( 状态 LED 闪
TX 声码器
烁 )。
IC324
DSP
• 应由 IC324 执行的操作无法得到处理。
• IC324 失控。
NXR-700H
可能出现的故障
107
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