mc68hc908mr24 Freescale Semiconductor, Inc, mc68hc908mr24 Datasheet - Page 394

• Manufacturer Part Number: mc68hc908mr24
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Glossary
Advance Information
394
CPU08 — The central processor unit of the M68HC08 Family.
CPU cycles — A CPU clock cycle is one period of the internal bus-rate
CPU registers — Memory locations that are wired directly into the CPU
CSIC — customer-specified integrated circuit
cycle time — The period of the operating frequency: t
decimal number system — Base 10 numbering system that uses the
direct memory access module (DMA) — An M68HC08 Family module
DMA — See direct memory access module (DMA).
DMA service request — A signal from a peripheral to the DMA module
duty cycle — A ratio of the amount of time the signal is on versus the
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clock, f
two or more so the high and low times will be equal. The length of
time required to execute an instruction is measured in CPU clock
cycles.
logic instead of being part of the addressable memory map. The CPU
always has direct access to the information in these registers. The
CPU registers in an M68HC08 are:
digits zero through nine.
that can perform data transfers between any two CPU-addressable
locations without CPU intervention. For transmitting or receiving
blocks of data to or from peripherals, DMA transfers are faster and
more code-efficient than CPU interrupts.
that enables the DMA module to transfer data.
time it is off. Duty cycle is usually represented by a percentage.
A, 8-bit accumulator
H:X, 16-bit index register
SP, 16-bit stack pointer
PC, 16-bit program counter
CCR, condition code register containing the V, H, I, N, Z, and C
bits
OP
, normally derived by dividing a crystal oscillator source by
Glossary
MC68HC908MR24
CYC
= 1/f
MOTOROLA
—
OP
Rev. 4.0
.