Motorola EP450 Basic Service Manual page 91

G-2
Term
PLL
PTT
RAM
Registers
RESET
RF PA
RIB
ROM
RSSI
RPT/TA
Softpot
Software
SPI (clock and data
lines)
Squelch
Standby Mode
TOT
TPL
µC
UHF
µP
VCO
VCOBIC
VHF
VSWR
December 3, 2003
Phase-Locked Loop: a circuit in which an oscillator is kept in phase with a refer-
ence, usually after passing through a frequency divider.
Push-To-Talk: the switch located on the left side of the radio; when pressed,
causes the radio to transmit.
Random Access Memory: the radio's RAM is loaded with a copy of the EEPROM
data.
Short-term data-storage circuits within the microcontroller.
Reset line: an input to the microcontroller that restarts execution.
Radio Frequency Power Amplifier
Radio Interface Box
Read Only Memory
Received Signal-Strength Indicator: a dc voltage proportional to the received RF
signal strength.
Repeater/Talk Around
A computer-adjustable electronic attenuator
Computer programs, procedures, rules, documentation, and data pertaining to
the operation of a system.
Serial Peripheral Interface: how the microcontroller communicates to modules
and ICs through the CLOCK and DATA lines.
Muting of audio circuits when received signal levels fall below a pre-determined
value.
An operating mode whereby the radio is muted but still continues to receive data
Time-Out Timer: a timer that limits the length of a transmission.
Tone Private-line
Microcontroller
Ultra High Frequency
Microprocessor
Voltage-Controlled Oscillator: an oscillator whereby the frequency of oscillation
can be varied by changing a control voltage.
Voltage-Controlled Oscillator Buffer Integrated Circuit
Very High Frequency
Voltage Standing Wave Ratio
Definition
HKLN4215A