Product Manual - Disc Drive SCSI-2/SCSI-3 Interface (Vol. 2; Ver. 2), Rev. E 137
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[3] The Save Mode Parameters (SMP) bit, when set to one, requests that the disc drive save the savable
pages. The format related parameters in the block descriptor, pages 3 and 4 are saved during a Format
command as well as a Mode Select command with SMP = 1. The disc drive must update the Current
mode values with parameters included with this command, save the Current values of the savable pa-
rameters, and report Good status only after the save operation is completed. The Saved parameters are
not changed if an error is detected during the Mode Select command. When the SMP bit is set to zero,
the Saved parameter values are not changed.
[4] The Parameter List Length specifies the length in bytes of the Mode Select parameter list that shall be
transferred during the Data Out phase. A Parameter List Length of zero indicates that no data shall be
transferred. This condition shall not be considered as an error.
[5] See “Control Byte” paragraph 4.2.6.
The Mode Select parameter list (Table 5.2.1-13) contains a four byte header, followed by zero or one block
descriptor, followed by the pages of Mode Select Parameters.
Acceptable values for the Mode Select parameter list for the disc drive are shown in Table 5.2.1-13.
The target terminates all the Mode Select commands with Check Condition status, sets the sense key to
ILLEGAL REQUEST and sets the additional sense code to Invalid Field In Parameter List,
and does not
change any mode parameters for the following conditions:
1.
If
the Strict mode is enabled (see note [5] of Table 5.2.1-31) and the initiator attempts to change any field
that is not changeable
by the host as reported by the target. In this case, no parameters are changed by
this command.
The target compares the parameters against the values as they were prior to this Mode
Select command. (The host shall not be penalized by values, not changeable by the host, which have a
target “ripple change” as a result of this Mode Select).
2.
If the initiator attempts to send an unsupported value or, a non-zero value to a reserved field in the Mode
Select header, block descriptor, or any page header.
3.
If an initiator attempts to send a page with a length not equal to the parameter length reported for that
page by the Mode Sense command.
4.
If the initiator attempts to send a value for a
changeable parameter that is outside the range supported by
the target and rounding is not implemented for that parameter (see note [4], Table 5.2.1-31).
5.
If the initiator sends a page descriptor with an unsupported page code value and the Strict mode is
enabled. See note [5] of Table 5.2.1-31.
If the initiator sends a value for a
changeable parameter that is outside the range supported by the target and
rounding is implemented for that parameter, the target shall either:
(1) round the parameter to an acceptable value and
if Round is one, terminate the command as described in
4.8.
(2) round the parameter to an acceptable value and if Round equals zero, terminte the command as if an
acceptable value had been sent from the initiator.
A target may alter any mode parameter in any mode page (even parameters reported as non-changeable) as
a result of changes to other mode parameters.
