Motorola XTL 1500, Detailed Service Manual, Page: 436 / 452

6815854H01-A June 15, 2005
Glossary-5
microcontroller unit Also written as µC. A microprocessor that contains RAM and ROM
components, as well as communications and programming components
and peripherals.
microprocessor core The central processing unit of the microprocessor and DSP IC and
powered by a lower voltage supply than the logic I/O section.
MISO See Master In Slave Out.
MOSI See Master Out Slave In.
multiplexer An electronic device that combines several signals for transmission on
some shared medium (e.g., a telephone wire).
MUX See multiplexer.
NiCd Nickel-cadmium.
NiMH Nickel-metal-hydride.
OMPAC See over-molded pad-array carrier.
open architecture A controller configuration that utilizes a microprocessor with extended
ROM, RAM, and EEPROM.
oscillator An electronic device that produces alternating electric current and
commonly employs tuned circuits and amplifying components.
OSW See outbound signaling word.
OTAR See over-the-air rekeying.
outbound signaling
word Data transmitted on the control channel from the central controller to the
subscriber unit.
over-molded pad-
array carrier A Motorola custom IC package, distinguished by the presence of solder
balls on the bottom pads.
over-the-air rekeying Allows the dispatcher to remotely reprogram the encryption keys in the
radio.
PA Power amplifier.
paging One-way communication that alerts the receiver to retrieve a message.
Patriot IC A dual-core processor that contains an MCU and a DSP in one IC
package.
PC Board Printed Circuit Board. Also referred to as a PCB.
phase-locked loop A circuit in which an oscillator is kept in phase with a reference, usually
after passing through a frequency divider.
PL See private-line tone squelch.
Term Definition