Avago Technologies LSI53C140 User Manual
Page 72
C-4
Glossary
Ver. 2.1
Copyright © 1998–2001 by LSI Logic Corporation. All rights reserved.
LSB
Abbreviation for Least Significant Bit or Least Significant Byte. That
portion of a number, address or field that occurs right-most when its value
is written as a single number in conventional hexadecimal or binary
notation. The portion of the number having the least weight in a
mathematical calculation using the value.
LUN
Logical Unit Number. Used to identify a logical unit.
Mandatory
A characteristic or feature that must be present in every implementation of
the standard.
MHz
MegaHertz – Measurement in millions of Hertz per second. Used as a
measurement of data transfer rate.
microsecond
(
µ
s)
One millionth of a second.
MSB
Abbreviation for Most Significant Bit or Most Significant Byte. That portion
of a number, address or field that occurs left-most when its value is
written as a single number in conventional hexadecimal or binary
notation. The portion of the number having the most weight in a
mathematical calculation using the value.
MSG/
Message – Driven active by a target during the Message Phase. This
signal is received by the initiator.
nanosecond
(ns)
One billionth of a second.
Negated
A signal is negated or deasserted when it is in the state opposite to that
which is indicated by the name of the signal. Opposite of asserted.
Negation
The act of driving a signal to the false state or allowing the cable
terminators to bias the signal to the false state.
Parity
A method of checking the accuracy of binary numbers. An extra bit, called
a parity bit, is added to a number. If even parity is used, the sum of all 1s
in the number and its corresponding parity is always even. If odd parity is
used, the sum of the 1s and the parity bit is always odd.
Peripheral
device
A device that can be attached to the SCSI bus. Typical peripheral devices
are disk drives, tape drives, printers, CD ROMs, or communications units.
Phase
One of the eight states to which the SCSI bus can be set. During each
phase, different communication tasks can be performed.
Port
A connection into a bus.