SCSI Description
Quantum Atlas 10K II Ultra160/m SCSI Hard Disk Drives 5–103
5.16 MODE SENSE (6) Command (1Ah)
The MODE SENSE (6) command allows the initiator to read the drive's sector
descriptor and mode pages. The MODE SENSE Command Descriptor Sector is
shown in Figure 5–42 and the data fields are described in Table 5–45. The Mode
Parameter Header is shown in Figure 5–43 and the data fields are described in Table
5-46.
Bit
Byte
7 6 5 4 3 2 1 0
0 Operation Code (1Ah)
1 Logical Unit Number
Reserve
d
DBD Reserved
2 PC Page Code
3 Reserved
4 Allocation Length
5 Control
Figure 5–42 MODE SENSE (6) Command Descriptor Block — Data Format
Table 5–45 MODE SENSE Command — Field Descriptions
Data Field Description
DBD Disable Block Descriptor. When the value is 0, the drive returns its Block
Descriptor followed by the requested page(s). When the value is 1, the
drive returns only the requested pages.
PC Page Control. Determines which type of page values are returned. These
values are:
00b Current
01b Changeable
10b Default
11b Saved
Page Code The Page Code field determines the pages to be returned to the initiator
in the command's data-in buffer transfer. Refer to Tables 5-26 and 5-47
for a complete list of the Mode Pages (changeable and read-only). A
Page Code of 3Fh causes all supported pages to be returned.
