Product Manual - Disc Drive SCSI-2/SCSI-3 Interface (Vol. 2; Ver. 2), Rev. E
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Ignore Wide Residue
The Ignore Wide Residue message is not an extended message, but it is placed here in context with the 16-
bit Wide Data Transfer message, since it applies when the 16-bit wide data transfer capability is used.
Table 3.5.3-6. Ignore wide residue message format
Bit
7
6
5
4
3
2
1 0
Byte(s)
0
Message Code (23h)
1
Ignore (01h, 02h, 03h)
The IGNORE WIDE RESIDUE message (Table 3.5.3-6) shall be sent from a target to indicate that the num-
ber of valid bytes sent during the last REQ/ACK handshake of a DATA IN phase is less than the negotiated
transfer width. The ignore field indicates the number of invalid data bytes transferred. This message shall be
sent immediately following that DATA IN phase and prior to any other messages. The ignore field is defined
in Table 3.5.3-7.
Note.
More than one IGNORE WIDE RESIDUE message may occur during an I/O process.
Table 3.5.3-7. Ignore field definition
Ignore
Invalid Data Bits
16-bit Transfers
00h
Reserved
01h
DB(15-8)
02h
Reserved
03h
Reserved
04h - FFh
Reserved
Even though a byte is invalid its corresponding parity bit shall be valid for the value transferred.
