Digital & Audio Section - Motorola MTP700 Detailed Service Manual

TRANSCEIVER 800 MHz
Digital & Audio Section
The digital section includes the RedCap2 host micro-processor which is the controller of
the Digital/RF Board. It controls the operation of the audio and transmitter, receiver, and
synthesizer integrated circuits located in the RF section. It has the serial communication
interface to communicate with the keypad, display and other internal peripherals.
For audio, the RedCap2 contains a Digital Signal Processor (DSP) which performs mod-
ulation and de-modulation functions for the radio. It also performs ACELP speech coding
and Forward Error Correction.
Major components of the digital section are:
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MTP700 Portable Radio / Detailed Service Manual
RedCap2 (microprocessor with DSP embedded)
GCAP3 (DC power supply and audio amplifier circuits)
Serial peripheral interface (SPI)
External host memories (Flash and SRAM)
Keypad block & circuits
LCD (liquid-crystal display) circuits.
Bottom connector & side connector interface circuits
4.2 - 5