This is a list of SCSI message codes.
A SCSI message code is a computer term which defines how SCSI devices send interface management information. The message code comprises one or more bytes.
The first byte of the message determines the format:
| 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) |
| 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 |
| 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 |