GL - 2 C156-E097-01EN
Spindle
The disk drive section that contacts the disk and
hub.
Sense key
A 4-bit code set in sense data. This information
is used to classify the type of error detected.
Sense code
One-byte code In sense data. This information
specifies the type of error detected.
Sense data
Information created by the target to post the
details of error information at the command
termination state.
Target (TARG)
An SCSI device activated by the initiator
(INIT). The target executes an input-output
operation. In this manual, target is sometimes
abbreviated as TARG.
Disk reference surface
Defined as an ideally flat ring surface of an
ideal spindle that contacts the disk clamped
area. Perpendicular to the axis of rotation.
Disconnect
Processing performed by the target during the
command execution processes. The target
temporarily releases the connect state between
an SCSI bus and an initiator when no further
operation on an SCSI bus is required.
Bus condition
An asynchronous condition for changing the
transition of SCSI bus state. The two bus
conditions are attention and reset.
Bus phase
SCSI bus state. An SCSI bus has the following
states:
• Bus free phase
• Arbitration phase
• Selection phase
• Reselection phase
• Information transfer phase
The information transfer phase is further
classified into the following phases according to
the type of information to be transferred.
• Data in phase
• Data out phase
• Command phase
• Status phase
• Message in phase
• Message out phase
Message
Control information for a series of bus phases
and execution sequence of input-output
operations. Messages are transmitted between
the initiator and the target active on an SCSI
bus.
Reconnect
Processing performed by the target that
executed the disconnect processing. The target
reconnects the initiator when operation on an
SCSI bus is necessary.
Logical unit
The unit of devices subject to input-output
operation on an SCSI bus.
Common command set (CCS)
The standard SCSI logical specifications
stipulated by the ANSI working committee.
The CCS defines the standard functions of
direct access devices (like magnetic disks).
Command descriptor block (CDB)
A series of data that describes the input-output
operation commands. The CDB is sent from the
initiator to the target.
Logical unit number (LUN)
A device address used to identify a logical unit.
Small computer system interface (SCSI)
Input-output interface standardized by ANSI.
[Rating code: ANSI X3.131-1986]