136 Product Manual - Disc Drive SCSI-2/SCSI-3 Interface (Vol. 2; Ver. 2), Rev. E
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5.2.1.7
Mode Select (6) Command (15h)
Table 5.2.1-12. Mode Select (6) Command
Bit
7
6
5
4
3
2
1
0
Byte(s)
0
0
0
0
1
0
1
0
1
1
Logical Unit No.[1]
PF
SMP
0
0
0
[2]
0
0
0
[3]
2
0
0
0
0
0
0
0
0
3
0
0
0
0
0
0
0
0
4
Parameter List Length
[4]
5
0
0
0
0
0
0 Flag Link [5]
The Mode Select command (Table 5.2.1-12) provides a means for the initiator to specify medium, logical unit,
or peripheral device parameters to the disc drive. The drive also implements the Mode Sense command (See
5.2.1.10). Initiators should issue Mode Sense prior to Mode Select to determine supported pages, page
lengths, and other parameters.
The drive maintains a separate set of mode parameters for each initiator that could be on the SCSI bus (7 or
15), regardless of whether or not more than one initiator actually exists on the bus. If an initiator sends a
Mode Select command that changes any parameters that apply to other initiators, the drive generates a Unit
Attention condition for all initiators except the one that issued the Mode Select command. The drive sets the
additional sense code to Mode Parameters Changed.
Notes.
[1] LUN must be zero
[2] The Page Format (PF) bit, when set to one, indicates the data sent by the initiator after the mode select
Header and Block Descriptors (if any) complies with the Page Format. The PF bit, when set to zero,
indicates the data sent after the Mode Select Header and the Block Descriptors (if any) are vendor
unique. The disc drive does not interpret the PF bit. It assumes the Page Format mode.
