Motorola MTM700

THEORY OF OPERATION (400 MHz) MTM700 Mobile Radio / Detailed Service Manual 4.1 - 9
Controller Section
The controller section contains the RedCap2 dual core (DSP / RISC) processor and its external
memory, the TX and RX audio processing, the serial interfaces and I/O circuitry. The RedCap2 and
its external memory is placed on a sub-board in the controller section.
The RedCap2 controls the receive / transmit frequencies, power levels, control head display and
keypad, serial interfaces, accessories, MMI, and other radio functions. This microprocessor can be
operated through the RS232 interface by a personal computer to program the FLASH.
The TX audio circuitry selects between the different microphone inputs, controls the TX audio level
and converts the analog audio signal to a digital format.
The RX audio circuitry converts the received signal from digital format to an analog audio signal,
performs volume control and amplifies the signal to speaker level.
The DSP performs signalling, and voice encoding and decoding.
Figure 5 Controller Block Diagram
AGC_0_FE
AGC_1_FE
AGC_2_IF
ABACUS III
ADDAG
ABACUS III
ADDAG
LNODCT
LVFRACN
ESCORT
PCIC
ADDAG_TXE
LO2_ON
REDCAP2
BBP
SAP
QSPIA
QSPIB
UARTA
UARTB
GPIO
EIM
MCU
DSP
HDI
Controller
Module
L1T
1V8
3V
RAM
512
kByte
RTC
DAC
FLASH
4
MByte
CODEC
MC145483
Audio
MUX
E2POT
Audio-PA
Option Slot
40pin
16
+
4 pin
7 pin
(option)
12 pin
40 pin
Front
Connector
Rear
Connector
UART
4 wire
RS232
18 pin Flexconn
on board
(option)
Level
shifter
& buffer
Level
shifter
&
buffer
Mux control
PA enable
SPIB
SB9600 / RS232
SBEP
A+
SW B+
5V
Mic+RXaudio,
Speaker audio
Keyfail/
Flash
Internal Flex
SPIB
I/O
Ignition & Emergency
SW B+
On/Off Ctr
SAP
Emergency
Ext. Alarm
Ext. PTT
Ignition
Mic
Mic
ON_OFF_CTRL /
EXP_ REQ
16.8 MHz
from LVFRAC_N
32.768 kHz
Soft turn off
On/Off Ctr
J0500
J0400
J0570
J0450
SAP
SPIB
P0701
PWM-ADC
PA Temp.Sense
Battery Voltage
J0550
8 wire
4 wire