Controller Board; General - Motorola GP328 Detailed Service Manual

4-2
When low battery level is detected by the microprocessor through both conditions above, it will store
the radio personality data to EEPROM before turning off.
3.0

Controller Board

3.1

General

The controller board is the central interface between the various subsytems of the radio. It is
separated into digital and audio architectures. The digital portion consists of a special Motorola
microcontroller (HC11FL0). The audio power amplifier (Audio PA) and audio/signalling/filter/
companding IC (ASFIC_CMP) form the backbone of the audio/signalling architecture.
16.8 MHz
Reference Clock
from Synthesizer
Recovered Audio
Squelch
To RF Board
To Synthesizer
Mod
Out
ASFIC_CMP
3.3V
Regulator
(Vdda)
SPI
Digital
Architecture
3.3V
Regulator
(Vddd)
Figure 4-2: Controller Block Diagram
Audio/Signalling
Architecture
Audio
PA
µP Clock
RAM
EEPROM
HC11FL0
ROM
Controller Board
External
Microphone
Internal
Microphone
External
Speaker
Internal
Speaker
SCI to Side
Connector