View source for List of SCSI message codes

{{Short description|none}}
This is a '''list of SCSI message code'''s.

A SCSI message code is a computer term which defines how [[Engineering:SCSI|SCSI]] devices send [[Interface (computing)|interface]] management information.  The message code comprises one or more [[Byte|bytes]].

==List of message formats==
The first byte of the message determines the format:

{| class="wikitable sortable"
|-
!Value
!Message format
|-
| 00h
| One-byte message (COMMAND COMPLETE)
|-
| 01h
| Extended messages
|-
| 02h-1Fh
| One-byte messages
|-
| 20h-2Fh
| Two-byte messages
|-
| 30h-7Fh
| Reserved
|-
| 80h-FFh
| One-byte message (IDENTIFY)
|}

==List of message codes==

{| class="wikitable sortable"
|-
!Value
!Message name
!Format
|-
| 00h
| COMMAND COMPLETE
|
|-
| 01h
| EXTENDED MESSAGE
| 01nnyy... - nn is the length, yy is the extended message code
|-
| 02h
| SAVE DATA POINTER
|
|-
| 03h
| RESTORE POINTERS
|
|-
| 04h
| DISCONNECT
|
|-
| 05h
| INITIATOR DETECTED ERROR
|
|-
| 06h
| ABORT
|
|-
| 07h
| MESSAGE REJECT
|
|-
| 08h
| NO OPERATION
|
|-
| 09h
| MESSAGE PARITY ERROR
|
|-
| 0Ah
| LINKED COMMAND COMPLETE
|
|-
| 0Bh
| LINKED COMMAND COMPLETE (WITH FLAG)
|
|-
| 0Ch
| BUS DEVICE RESET
|
|-
| 0Dh
| ABORT TAG
|
|-
| 0Eh
| CLEAR QUEUE
|
|-
| 0Fh
| INITIATE RECOVERY
|
|-
| 10h
| RELEASE RECOVERY
|
|-
| 11h
| TERMINATE I/O PROCESS
|
|-
| 12h-1Fh
| Reserved
|
|-
| 20h
| SIMPLE QUEUE TAG
| 20nn - where nn is the queue tag
|-
| 21h
| HEAD OF QUEUE TAG
| 21nn - where nn is the queue tag
|-
| 22h
| ORDERED QUEUE TAG
| 22nn - where nn is the queue tag
|-
| 23h
| IGNORE WIDE RESIDUE
| 230i - where i is the number of bytes to ignore (can be 1, 2 or 3)
|-
| 24h-2Fh
| Reserved for two-byte messages
|
|-
| 30h-7Fh
| Reserved
|
|-
| 80h-FFh
| IDENTIFY
|
|}

==List of extended message codes==
{| class="wikitable sortable"
|-
!Value
!Length
!Message name
!Format
|-
| 00h
| 05h
| MODIFY DATA POINTER
| 010500aaaa - where aaaa is added to the current data pointer
|-
| 01h
| 03h
| SYNCHRONOUS DATA TRANSFER REQUEST
| 010301pprr - where pp is the period and rr is the REQ/ACK offset
|-
| 02h
| nn
| Reserved - was formerly used for the EXTENDED IDENTIFY message in SCSI-1
| 01nn02...
|-
| 03h
| 02h
| WIDE DATA TRANSFER REQUEST
| 010203ee - where ee is the transfer width exponent
|-
| 04h-7Fh
|
| Reserved
|
|-
| 80h-FFh
|
| Vendor-specific
|
|}
==References==
* [http://www.staff.uni-mainz.de/tacke/scsi/SCSI2-06.html SCSI-2 Spec - Logical Characteristics]

[[Category:SCSI]]
[[Category:Computing-related lists|SCSI message codes]]

{{Sourceattribution|List of SCSI message codes}}