Motorola GM Series, Service Manual, Page: 24 / 28

2-8 MAINTENANCE
RAM CS RAM Ship Select
RDY Service Request Line from Option Board
REF CS Reference Chip Select (not used)
RESET Reset Line
ROW x Keypad Matrix Row x
RSSI Received Signal Strength Indicator
RX ADAPT Flat TX Path Disable during Transmitter Key-up
RX AUD RTN Option Board Input / Output of Receiver Audio Path
RX FLAT FILTERED AUDIO Flat or Filtered Audio to Accessory Connector
RXIN RF Signal from Antenna Switch into the Receiver
RXINJ RF Signal from the VCO into the Mixer
SCI RX Serial Communication Interface Receive Line
SCI TX Serial Communication Interface Transmit Line
SPI Serial Peripheral Interface Bus
SPKR- Negative Audio PA Speaker Output
SPKR+ Positive Audio PA Speaker Output
SQ DET Squelch Detect Signal
SYN *P Clock Signal
TEMP SENSE Temperature Sense Line for LCD
TEMPSENSE Temperature Sense Line from PA to *P
TRB TX/RX VCO Switch Signal
TX AUD RTN Option Board Output to Transmit Audio Path
TX AUD SND Microphone Audio to Option Board
TXINJ RF Signal from the VCO into the Transmitter PA
U DRIVER Supply Voltage for PA Driver
U PREDRIVER Supply Voltage for PA Pre-driver
UNSW 5V Permanent 5V Supply
URX SND Filtered Audio Signal to Option Board
VAG 2.5V Reference Voltage for Analog Circuitry
VCOBIAS 1 Switch Signal from Synthesizer
VCOBIAS 2 Switch Signal from Synthesizer
VCOMOD Modulation Signal into VCO
VCTRL VCO Frequency Control Voltage
VDDA Regulated 5V for Digital Circuitry in RF Section
VOLTAGE SENSE Voltage Sense Line from LCD
VOLUME Volume Pot Output
VOX Voice Operated Transmit Level
VPP Boot Mode Select
VS AUDIOSEL Switch Signal to Enable Option Board Audio Output Signal
VS GAINSEL Voice Storage Gain Select Line
VS INT Voice Storage Interrupt Line