SCSI Mode Select Command
The SCSI Mode Select command is used to modify device information contained in mode pages in a SCSI target device. There are two different versions of the command, a 6 byte version and a 10 byte version.
The CDB structure for the Mode Select(6) command is:
bit→ |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
|---|---|---|---|---|---|---|---|---|
0 |
Operation code = 15h |
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1 |
LUN |
PF |
Reserved |
SP |
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2 |
Reserved |
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3 |
Reserved |
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4 |
Parameter list length |
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5 |
Control |
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The CDB structure for the Mode Select(10) command is:
bit→ |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
|---|---|---|---|---|---|---|---|---|
0 |
Operation code = 55h |
|||||||
1 |
LUN |
PF |
Reserved |
SP |
||||
2 |
Reserved |
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3 |
Reserved |
|||||||
4 |
Reserved |
|||||||
5 |
Reserved |
|||||||
6 |
Reserved |
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7–8 |
Parameter list length |
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9 |
Control |
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The special control fields in the CDB have the following meaning:
- PF - Page Format:
- 0 - SCSI-1 compliant (vendor-specific)
- 1 - SCSI-2 compliant
- SP - Save Pages - if this bit is one then the target will save any saveable updates to non-volatile memory or media area.