User's Manual

68P80801E35-B 5/1/2002 9
EBTS System Manual - Vol 2 Base Radio Controllers
Enhanced Base Radio Controller
Enhanced Base Radio Controllers Theory of Operation
Table 6 briefly describes the EBRC circuitry. Figure 15 is a functional block
diagram of the EBRC.
MPC860 Host Microprocessor
The MPC860 host microprocessor is the main controller for the BR. The processor
operates at a 50-MHz clock speed. The processor controls Base Radio operation
according to station software in memory. Station software resides in FLASH
memory. For normal operation, the system transfers this software to non-volatile
memory. An EEPROM contains the station codeplug.
NOTE
At BR power-up, the EBRC LED indicates a major
alarm. This indication continues until BR software
achieves a predetermined state of operation.
Afterward, the software turns off the EXBRC LED.
Table 6 EBRC Circuitry
Circuit Description
Host Microprocessor Contains integrated circuits that comprise the central controller
of the EBRC and station
Non-Volatile Memory Consists of:
• FLASH containing the station operating software
• EEPROM containing the station codeplug data
Volatile Memory Contains SDRAM to store station software used to execute
commands.
Ethernet Interface Provides the EBRC with a 10Base2 Ethernet communication
port to network both control and compressed voice data
RS-232 Interface Provides the EBRC with an RS-232 serial interface
Digital Signal Processors Performs high-speed modulation/demodulation of
compressed audio and signaling data
TISIC Contains integrated circuits that provide timing reference
signals for the station
TX Reclock Contains integrated circuits that provide highly stable,
reclocked transmit signals and peripheral transmit logic
Station Reference Circuitry Generates the 16.8 MHz and 48 MHz reference signals used
throughout the station
Input Ports Contains 16 signal input ports that receive miscellaneous
inputs from the BR
Output Ports Contains 40 signal output ports, providing a path for sending
miscellaneous control signals to circuits throughout the BR
Remote Station Shutdown Provides software control to cycle power on the BR