M68ICS08KX datasheet(66/77 Pages) MOTOROLA

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Glossary

M68ICS08KX In-Circuit Simulator

User’s Manual

MOTOROLA

Glossary

cycles — See CPU cycles.

data bus — A set of conductors that are used to convey binary information

from a CPU to a memory location or from a memory location to a CPU;

in the MC68HC908KX8, the data bus is 8-bits.

development tools — Software or hardware devices used to develop computer

programs and application hardware. Examples of software

development tools include text editors, assemblers, debug monitors,

and simulators. Examples of hardware development tools include

simulators, logic analyzers, and PROM programmers. An in-circuit

simulator combines a software simulator with various hardware

interfaces.

EPROM — Erasable, programmable read-only memory. A non-volatile type

of memory that can be erased by exposure to an ultra-violet light

source. MCUs that have EPROM are easily recognized by their

packaging: a quartz window allows exposure to UV light. If an

EPROM MCU is packaged in an opaque plastic package, it is termed a

one-time-programmable OTP MCU, since there is no way to erase and

rewrite the EPROM.

EEPROM — Electrically erasable, programmable read-only memory.

H — Abbreviation for half-carry in the condition code register of the

MC68HC908KX8. This bit indicates a carry from the low-order four

bits of an 8-bit value to the high-order four bits. This status indicator is

used during BCD calculations.

I — Abbreviation for interrupt mask bit in the condition code register of the

MC68HC908KX8.

index register — An 8-bit CPU register in the MC68HC908KX8 that is used

in indexed addressing mode. The index register (X) also can be used as

a general-purpose 8-bit register in addition to the 8-bit accumulator.

input-output (I/O) — Interfaces between a computer system and the external

world. For example, a CPU reads an input to sense the level of an

external signal and writes to an output to change the level on an

external signal.

M68ICS08KX Datasheet(PDF) 66 Page - Motorola, Inc