Motorola GM950E Service Manual page 35

Paragraph
1.0 Overview..................................................................................................... 1
2.0 Controller.................................................................................................... 2
2.1 General ........................................................................................................ 2
2.2 Voltage Regulators ...................................................................................... 2
2.3 Electronic On/Off ......................................................................................... 3
2.4 Mechanical On/Off ....................................................................................... 3
2.5 Ignition ......................................................................................................... 3
2.6 Hook ............................................................................................................ 4
2.7 Microprocessor Clock Synthesizer .............................................................. 4
2.8 Serial Peripheral Interface (SPI) .................................................................. 4
2.9 SBEP Serial Interface .................................................................................. 5
2.10 General Purpose Input/Output..................................................................... 5
2.11 Normal Microprocessor Operation............................................................... 5
2.12 Control Head Model A2 or A3...................................................................... 6
3.0 General ....................................................................................................... 7
3.1 Audio Filter IC (AFIC) .................................................................................. 7
3.2 Audio Ground............................................................................................... 7
4.0 Transmit Audio Circuits............................................................................. 7
4.1 Mic Input Path.............................................................................................. 7
4.2 External Mic Path......................................................................................... 8
4.3 PTT Sensing and TX Audio Processing ...................................................... 8
4.4 Option Board Audio (GM950i only).............................................................. 9
5.0 Transmit Signalling Circuits ................................................................... 10
5.1 Sub-audible Data (PL/DPL) ....................................................................... 10
5.2 High Speed Data and DTMF ..................................................................... 11
Theory of Operation
Chapter 4
Theory of Operation
Table of Contents
Table of Contents
Page
4-i