s908ey8ad4cfjer Freescale Semiconductor, Inc, s908ey8ad4cfjer Datasheet - Page 262

• Manufacturer Part Number: s908ey8ad4cfjer
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Glossary
full-duplex transmission — Communication on a channel in which data can be sent and received
H — The upper byte of the 16-bit index register (H:X) in the CPU08.
H — The half-carry bit in the condition code register of the CPU08. This bit indicates a carry from the
hexadecimal — Base 16 numbering system that uses the digits 0 through 9 and the letters A through F.
high byte — The most significant eight bits of a word.
illegal address — An address not within the memory map
illegal opcode — A nonexistent opcode.
I — The interrupt mask bit in the condition code register of the CPU08. When I is set, all interrupts are
index register (H:X) — A 16-bit register in the CPU08. The upper byte of H:X is called H. The lower
input/output (I/O) — Input/output interfaces between a computer system and the external world. A CPU
instructions — Operations that a CPU can perform. Instructions are expressed by programmers as
interrupt — A temporary break in the sequential execution of a program to respond to signals from
interrupt request — A signal from a peripheral to the CPU intended to cause the CPU to execute a
I/O — See “input/output (I/0).”
IRQ — See "external interrupt module (IRQ)."
jitter — Short-term signal instability.
latch — A circuit that retains the voltage level (logic 1 or logic 0) written to it for as long as power is applied
latency — The time lag between instruction completion and data movement.
least significant bit (LSB) — The rightmost digit of a binary number.
logic 1 — A voltage level approximately equal to the input power voltage (V
262
simultaneously.
low-order four bits of the accumulator value to the high-order four bits. The half-carry bit is required
for binary-coded decimal arithmetic operations. The decimal adjust accumulator (DAA) instruction
uses the state of the H and C bits to determine the appropriate correction factor.
disabled.
byte is called X. In the indexed addressing modes, the CPU uses the contents of H:X to determine the
effective address of the operand. H:X can also serve as a temporary data storage location.
reads an input to sense the level of an external signal and writes to an output to change the level on
an external signal.
assembly language mnemonics. A CPU interprets an opcode and its associated operand(s) and
instruction.
peripheral devices by executing a subroutine.
subroutine.
to the circuit.
MC68HC908EY16 • MC68HC908EY8 Data Sheet, Rev. 10
DD
).
Freescale Semiconductor