3. Glossary and Conventions

3.1 Glossary

byte.  In this standard, this term indicates an 8-bit (octet) byte.

command descriptor block (CDB).  The structure used to communicate requests 
from an initiator to a target.

connect.  The function that occurs when an initiator selects a target to start 
an operation.
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disconnect.  The function that occurs when a target releases control of the 
SCSI bus, allowing it to go to the BUS FREE phase.

initiator.  An SCSI device (usually a host system) that requests an operation 
to be performed by another SCSI device.

INTERMEDIATE status.  A status code sent from a target to an initiator upon 
completion of each command in a set of linked commands except the last command 
in the set.

logical unit.  A physical or virtual device addressable through a target.

logical unit number.  An encoded three-bit identifier for the logical unit.

LSB.  Least significant byte.

LUN.  Logical unit number.

mm.  Millimeter.

ms.  Millisecond.

MSB.  Most significant byte.

ns.  Nanosecond.

one.  A true signal value.

peripheral device.  A peripheral that can be attached to an  SCSI device 
(e.g., magnetic-disk, printer, optical-disk, or magnetic-tape).

reconnect.  The function that occurs when a target selects an initiator to 
continue an operation after a disconnect.

reserved.  The term used for bits, bytes, fields, and code values that are set 
aside for future standardization.

SCSI address.  The octal representation of the unique address (0-7) assigned 
to an SCSI device.  This address would normally be assigned and set in the 
SCSI device during system installation.

SCSI ID.  The bit-significant representation of the SCSI address referring to 
one of the signal lines DB(7-0).

SCSI device.  A host computer adapter or a peripheral controller or an 
intelligent peripheral that can be attached to the SCSI bus.

signal assertion.  The act of driving a signal to the true state.

signal negation.  The act of driving a signal to the false state or allowing 
the cable terminators to bias the signal to the false state (by placing the 
driver in the high impedance condition).

signal release.  The act of allowing the cable terminators to bias the signal 
to the false state (by placing the driver in the high impedance condition).

status.  One byte of information sent from a target to an initiator upon 
completion of each command.

target.  An SCSI device that performs an operation requested by an initiator.

us.  Microsecond.

vendor unique.  In this standard, this term indicates bits, fields, or code 
values that are vendor specific.

xxH.  Numbers followed by capital H subscript are hexadecimal values.  All 
other numbers are decimal values. 

zero.  A false signal value.

3.2 Editorial Conventions.  Certain words and terms used in this standard have 
a specific meaning beyond the normal English meaning.  These words and terms 
are defined either in the glossary (see 3.1) or in the text where they first 
appear (e.g., initiator).  Names of signals, phases, conditions, messages, 
commands, statuses, and sense keys are in all uppercase (e.g., REQUEST SENSE).  
Lowercase is used for words having the normal English meaning.

































