GLOSSARY (cont) - TM-11-6625-2937-130099

TM 11-8625-2937-13

ENC unit test

Power is applied to the unit test power connector for encoder unit test.

Extender card No 1

Extender, card for encoder (SM-D-942431-1). Used to extend an analog circuit

card in an encoder.

Extender card No. 2

Extender, card for control-interface unit (SM-D-942431-2). Used to extend an

analog circuit card in a control-interface unit.

Extender card No. 3

Extender, card for decoder (SM-D-942431-3). Used to extend an analog circuit

card in a decoder.

Front panel

Front panel and circuit card rack are part of circuit card assembly rack 1 A2. The

front panel contains controls and indicators including the mode select switch and the

mode/power indicators.

Gate

A circuit that produces an output that is dependent on the logical input of two or

more binary digits.

Hardware

All of the mechanical and electronic components necessary for proper operation

of the MPU.

Index register

A 16-bit register used to hold a memory address

The contents of the register is

used under program control as a counter or to modify the address of the next

instruction to be executed.

Instruction word

A byte, or pattern of eight bits, that represents a command or operand rather than

a binary number.

IRQ

Interrupt request. This input signal requests that an interrupt sequence be generated within the MPU.

The MPU waits until it completes the current instruction

that is being executed before it recognizes the request.

Look-up tables

Data constants stored with program of instructions in ROM's.

LSB

Least significant bit. LSB is referred to as bit 0.

Memory

The memory is a storage device in which a sequence of instructions and data is

stored. It is divided into a series of locations and each location stores one byte.

To enable these bytes to be retrieved, each location is allocated an address which does not change.

Module test circuit rack

Provides connections for encoder, decoder and control-interface unit,

microprocessor and standard logic cards to control interface unit.

Module test connector

Provides interface, between control-interface unit and microprocessor or standard logic cards.

MPU

Microprocessor unit. Responds to inputs and produces outputs in a manner determined by a sequence of

instructions which are stored in ROM.

MSB

Most significant bit. MSB is referred to as bit 7.

NMI

Non-maskable interrupt. A negative-going edge on this input requests that a NMI

sequence be generated within the MPU. However, the MPU completes the

current instruction that is being executed before it recognizes the NMI signal.

Port

An input or output path for transferring data or information.

PIT

Programmable interval timer. Sets a limit on the amount of time that a test can run.

Program

Any sequence of instructions which is self-contained and a complete solution to a

particular problem is called a program.

Program card

Each program card is a plastic card with a magnetic stripe containing the test pro-

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