Seagate Ultra 320 - Manual (Page 141)

Parallel SCSI Interface Product Manual, Rev. A 127
6.2.5 SPI status information unit
The SPI status information unit (see Table 54) contains the completion status of the task indicated by the pre-
ceding SPI L_Q information unit. The target shall consider the SPI status information unit transmission to be
successful when there is no attention condition on the transfer of the information unit.
If a task completes with a Good status, a SNSVALID bit of zero, and a RSPVALID bit of zero, then the target
shall set the Data Length field in the SPI L_Q information unit (see Section 6.2.2) to zero.
Table 54: SPI status information unit
[1] Reserved for Fiber Channel Protocol.
[2] A Sense Data Valid (SNSVALID) bit of zero indicates the sense data list length shall be ignored and no
sense data is provided. A SNSVALID bit of one indicates the Sense Data List Length field specifies the
number of bytes in the Sense Data field.
[3] If sense data is provided, the Sense Data Valid (SNSVALID) bit shall be set to one and the Sense Data
List Length field shall specify the number of bytes in the Sense Data field. The Sense Data List Length
field shall only contain even lengths greater than zero and shall not be set to a value greater than 252. If
no sense data is provided, the sense data valid bit shall be set to zero. The initiator shall ignore the Sense
Bit
Byte
7 6 5 4 3 2 1 0
0 Reserved
1 Reserved
2 Reserved Reserved for FCP [1]
SNSVALID
[2]
RSPVALID
[4]
3 STATUS [5]
4 MSB
SENSE DATA LIST LENGTH (n-m) [3]
7 LSB
8
MSB
PACKETIZED FAILURES LIST LENGTH [4]
11 LSB
12 MSB
PACKETIZED FAILURES [4]
m LSB
1+m MSB
SENSE DATA LIST [3]
n
LSB
n+1 MSB
iuCRC [6]
n+2
n+3
n+4 LSB