Unit Attention Parameters Page (00H) - Seagate SCSI Interface Product Manual

144
5.12.12

Unit Attention Parameters page (00h)

The Unit Attention Parameters page is the last page to be reported by the drive.
Table 101: Unit Attention Parameters page (00h)
Bit 7
Byte
0 1
PS [10]
1 Page Length (in bytes) [1]
2 0
Default
Changeable [9]
3 Reserved
Default [8]
Changeable [9]
Notes.
[1] The Page Length field specifies the length in bytes of the mode parameters that follow. If the initiator does
not set this value to the value that is returned for the page by the Mode Sense command, the drive shall
terminate the command with Check Condition status. The sense key shall be set to Illegal Request with
the additional sense code set to Invalid Field In Parameter List. The drive is permitted to implement a
mode page that is less than the full page length defined by this specification, provided no field is truncated
and the page length field correctly specifies the actual length implemented. If the Strict bit equals zero and
if the page length specified by the initiator is shorter than the actual page length, then the parameters are
transferred and the command ends with Good status if no other items cause the command to be rejected.
Caution: Utilization of this forgiving option by an initiator that does not analyze the impact of the trunca-
tion could adversely affect data integrity.
[2] If the enable Synchronous Select Mode (SSM) bit equals one, the drive initiates WDTR and SDTR mes-
sages when it recognizes that one may be required (after reset, reset message, or power cycle). If the
SSM bit equals zero, the drive does not initiate WDTR or SDTR regardless of negotiated conditions prior
to reset, reset message, or power cycle.
[3] When the Inquiry Length bit is set to 1, the standard Inquiry data available to a host is limited to the 36
bytes required by the SCSI-2 specification. When the IL bit is reset (0), 148 bytes of standard Inquiry data
are available. The Additional Length field in byte 4 of the Inquiry data is updated to reflect the actual num-
ber of additional bytes available.
[4] When the Unit Attention bit is set to 1, then Unit Attention is logged in sense only; no Check Condition Sta-
tus is presented following any reset. When this bit is Reset (0), then Check Condition is presented for all
affected initiators following a reset until Request Sense is issued by each initiator (as per current opera-
tion).
[5] When the Round bit equals one, the drive treats and reports rounded parameters as described in Section
4.8. When Round equals zero, the drive shall round the parameter and handle command completion
reporting as if the parameter had not been rounded.
[6] When the Strict bit is a one, the drive checks for initiator attempts to change unchangeable parameters. If
the drive detects an attempt, it rejects the command in the standard way, i.e., Check Condition status from
drive, Request Sense from the initiator, and Illegal Request sense key (5h) back from the drive. When the
Strict bit is zero, the drive ignores the values of the unchangeable parameters in a Mode Select command.
The drive does not reject the command trying to change unchangeable parameters.
6 5
0 0
Inquiry
SSM [2]
Length [3] Attention [4]
Self Seek
[11]
SCSI Interface Product Manual, Rev. J
4 3
0 0
Page Code (00h)
0
Unit
Round [5]
Reserved [8]
2 1
0 0
Strict [6] SCSI-2 [7]
0
0