Technical Manual

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Host Port Parallel memory mapped interface consisting of eight registers in the
DSP56001.
IC Integrated Circuit
IMBE A sub-band, voice encoding algorithm used in ASTRO digital voice.
ISW Inbound Signalling Word; data transmitted on the control channel from a
subscriber unit to the central control unit.
LSH Low Speed Handshake; 150 baud digital data sent to the radio during trunked
operation while receiving audio.
MCU MicroControl Unit
MDC Motorola Digital Communications
OMPAC Over-Molded Pad-Array Carrier; a Motorola custom IC package, distinguished
by the presence of solder balls on the bottom pads.
Open Architecture A controller configuration that utilizes a microprocessor with extended ROM,
RAM, and EEPROM.
OSW Outbound Signalling Word; data transmitted on the control channel from the
central controller to the subscriber unit.
PC Board Printed Circuit board
PL Private-Line
®
tone squelch; a continuous sub-audible tone that is transmitted
along with the carrier.
PLL Phase-Locked Loop; a circuit in which an oscillator is kept in phase with a
reference, usually after passing through a frequency divider.
PTT Push-To-Talk; the switch located on the left side of the radio which, when
pressed, causes the radio to transmit.
Registers Short-term data-storage circuits within the microcontrol unit or
programmable logic IC.
Repeater Remote transmit/receive facility that re-transmits received signals in order to
improve communications coverage.
RESET Reset line; an input to the microcontroller that restarts execution.
RF PA Radio Frequency Power Amplifier
RSS Radio Service Software
RPT/TA RePeaTer/Talk-Around
RX DATA Recovered digital data line.
Signal Qualifier
Mode
An operating mode whereby the radio is muted but still continues to analyze
receive data to determine RX signal type.