Motorola CP 140, Detailed Service Manual

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Controller Circuits 1-3
3.0 Controller Circuits
3.1 General
The controller board is the central interface between the various subsystems of the radio. It provides
the following functions:
■
interface with controls and indicators
■
serial bus control of major radio circuit blocks
■
encoding and/or decoding of selective signaling formats such as PL, DPL, MDC1200 and
QuikCall II
■
interface to CPS programming via the microphone connector
■
storage of customer-specific information such as channel frequencies, scan lists, and
signaling codes
■
storage of factory tuning parameters such as transmitter power and deviation, receiver
squelch sensitivity, and audio level adjustments
■
power-up, power-down and reset routines
In the UHF and VHF sections, the Radio Block Interconnect Diagram show the interconnections
between the controller and the various other radio blocks, while the Controller Interconnect
Schematic diagram (in this chapter) shows the connections between the following circuit areas
which comprise the controller block:
■
microprocessor circuitry
■
audio circuitry
■
DC regulation circuitry
■
rotary and pushbutton controls and switches
■
option board interface
The majority of the circuitry described below is contained in the Microprocessor Circuit schematic
diagrams. However, portions are also found in the DC Regulation and UHF/VHFAudio Circuit
schematics.