Station Control Module Operation - Motorola MTR2000 T5544 Instruction / Field Service Manual

Description

Station Control Module Operation

8
Introduction
The Station Control Module (SCM) is the microprocessor-based controller for the station.
Major components include an MC68356 microprocessor, which combines a 68302 Integrated
Multiprotocol Processor (IMP) with a 56002 Digital Signal Processor (DSP), a DSP ASIC de-
vice, and several Codec filter devices.
Station Control Module Operation
The MC68356 forms the heart of the SCM. The 68302 portion is the Host Microprocessor
(µP), which serves as the controller for the SCM and operates from station software stored in
FLASH memory. This software determines the system capabilities of the station. The Host
µP communicates with the station modules and the SCM circuitry via address and data buses,
three SCI (Serial Communication Interface) ports, and an SPI bus.
The DSP portion of the MC68356, with the support of the DSP ASIC, perform the necessary
digital processing for the station audio and data signals. The DSP circuitry interfaces with the
Receiver Module (receive audio), the Exciter Module (VCO modulation signal), the Wireline
Interface Board (wireline audio), and external audio devices (microphone and speaker).
The 2.1 MHz Reference Oscillator generates the reference signal used by the Receiver and
Exciter Modules.
68P81096E36-H
06/28/05