Zilog ZUSBOPTS - Manual (Page 489)

UM017105-0511 Glossary
Zilog Developer Studio II – ZNEO™
User Manual
461
CPU. Abbreviation for Central Processing Unit. 1. The portion of a computer that includes circuits control-
ling the interpretation and execution of instructions. 2. The portion of a computer that executes pro-
grammed instructions, performs arithmetic and logical operations on data, and controls input/output
functions.
D
debug. To detect, trace, and eliminate mistakes.
DI. Disable interrupt.
E
EI. Enable interrupt.
emulation. The process of duplicating the characteristics of one product or part using another medium. For
example, an In-Circuit Emulator (ICE) module duplicates the behavior of the chip it emulates, in the circuit
being tested.
emulator. An emulation device.
EOF. End of file—when all records in a file are processed, the computer encounters an end-of-file condi-
tion.
EPROM. Erasable Programmable Read-Only Memory. An EPROM can be erased by exposure to ultravio-
let light.
EQ. A Boolean operator meaning Equal to.
escape sequence. A special escape command is entered as three plus symbols (+++). placing the modem
in command mode, and interrupting user data transmission. However, the escape sequence does not termi-
nate the data connection. Command mode allows the entering of commands while the connection is main-
tained.
F
F. Falling Edge.
Fast Fourier Transform. An algorithm for computing the Fourier transform of a set of discrete data val-
ues. Given a finite set of data points—for example, a periodic sampling taken from a real-world signal—
the FFT expresses the data in terms of its component frequencies. It also solves the essentially identical
inverse problem of reconstructing a signal from the frequency data.
FFT. See Fast Fourier Transform.
filter. A process for removing information content, such as high or low frequencies.
flag. In data transmission or processing, an indicator, such as a signal, symbol, character, or digit, used for
identification. A flag may be a byte, word, mark, group mark, or letter that signals the occurrence of some
condition or event, such as the end of a word, block, or message.
frequency. For a periodic function, the number of cycles or events per unit time.