User's Manual

68P81093C75-O December 1, 2000 10-3
Station Control
Module
Introduction
The Station Control Module (SCM) is the microprocessor-based
controller for the station. Major components include the following:
• MC68360 microprocessor,
• 56002 Digital Signal Processor (DSP)
• Two Application Specific Integrated Circuit (ASIC) devices
(host and DSP).
Station Control Module
Operation
The Host Microprocessor (µP) serves as the controller for the SCM,
operating from the station software stored in FLASH memory. This
software determines the system capabilities of the station (analog,
ASTRO, SECURENET, etc.).
The Host µP communicates with the station modules and the SCM
circuitry via address and data buses, a High-Level Data Link Control
(HDLC) bus, and a Serial Peripheral Interface (SPI) bus. External
communications is accomplished using a serial port on the top panel.
The DSP and DSP ASIC perform the necessary digital signal
processing for the station audio and data signals. The DSP circuitry
interfaces with the Receiver Module (receive audio), the Exciter
Module (modulation signal), and the Wireline Interface Board
(wireline audio).
The 2.1 MHz Reference Oscillator generates the reference signal
used by the Receiver and Exciter Modules.
Wireline Interface
Board
Introduction The Wireline Interface Board (WIB) serves as the interface between
the customer telephone lines and the station. In general, the WIB
processes and routes all wireline audio signals between the station
and the landline equipment (such as consoles, modems, etc.).
Landline-to-station and station-to-landline audio signals are
connected to the WIB via RJ-45 connectors on the top panel of the
station.
Wireline Interface
Board Operation
The WIB contains the following:
• A microprocessor