Zilog EZ80F916 - Manual (Page 391)

eZ80
®
CPU
User Manual
UM007715-0415 Glossary
382
Glossary
absolute delay.
The time interval or phase difference between transmission and reception of a signal.
acknowledge character (ACK).
A transmission control character transmitted by the receiving station as
an affirmative response to the sending station.
active device.
A device that requires a source of energy for its operation and yields an output that is a
function of present and past input signals. Examples of active devices include controlled power supplies,
transistors, LEDs, amplifiers, and transmitters.
ADC.
Analog-to-Digital Converter—a circuit that converts an analog signal to a digital bit stream. See A/
D. Add with Carry; an arithmetic instruction.
ADD.
Add without Carry; an arithmetic instruction.
Add/Subtract Flag.
The Add/Subtract Flag is used by the decimal adjust accumulator instructions (DAA)
to distinguish between ADD and SUBTRACT instructions.
added bit.
A bit delivered to the intended destination user in addition to intended user information bits and
delivered overhead bits. Also called extra bit.
added block.
Any block, or other delimited bit group, delivered to the intended destination user in
addition to intended user information bits and delivered overhead bits. Also called extra block.
ADDR.
Address.
address lines.
The direct signals that go from the CPU to other devices connected to the bus.
address space.
The physical or logical area of the target system’s memory map. The memory map could
be physically partitioned into ROM to store code, and RAM for data. The memory can also be divided
logically to form separate areas for code and data storage.
ADL.
ADDRESS AND DATA LONG mode takes advantage of the eZ80 ® CPU’s 16 MB linear addressing
space, 24-bit CPU registers, and enhanced instruction set. Also called ADL MEMORY mode.
AFA, AFB.
Automatic Frequency control output A and B.
AGND.
Analog Ground.
Alternate register set.
One of two banks of working registers in the eZ80 ® CPU. The alternate register
set contains an 8-bit accumulator register (A’) and six 8-bit working registers (B’, C’, D’, E’, H’, and L’).
These six 8-bit alternate working registers can also be combined to function as the multibyte register pairs
BC’, DE’, and HL’. The 8-bit Flag register F’ completes the alternate register set. See Main register set.
ALU.
Arithmetic Logical Unit. The ALU is contained within the data block of the CPU. The ALU
performs the arithmetic and logic functions on the addresses and the data passed over from the control
block or from the CPU registers.
American National Standards Institute (ANSI).
The U.S. standards organization that establishes
procedures for the development and coordination of voluntary American National Standards.
ARAM.
Audio-Quality RAM.
architecture.
Of a computer, the physical configuration, logical structure, formats, protocols, and
operational sequences for processing data, controlling the configuration, and controlling the operations.
Computer architecture may also include word lengths, instruction codes, and the interrelationships among
the main parts of a computer or group of computers.