SCSI Commands: 23BMODE SENSE
Page
107
3.11.1
MODE SENSE Command Descriptor Block
3.11.1.1
MODE SENSE (6) Command Descriptor Block
Byte
Bits
7 6 5 4 3 2 1 0
0
Operation Code (1Ah)
1
Ignored LUN
Rsvd
DBD
Reserved
2
PC Page
Code
3
Reserved
4
Allocation Length
5
Control
3.11.1.2
MODE SENSE (6)Field Descriptions
Field
Bytes
Bits
Description
Operation
Code
0
The Operation Code for MODE SENSE(6) is 1Ah.
Ignored
Logical
Unit
1
5-7
The LUN field is vestigial from the SCSI-1 standard and is ignored.
DBD
1
3
0 = Return the block descriptor in the MODE SENSE data.
1 = Disable Block Descriptors (DBD).
NOTE: When the DBD is 1, the Block Descriptor Length in the
parameter header is 0.
PC
2
6-7
Page Control specifies the type of values to be returned.
00b = Report current values.
01b = Report changeable values. Any bit that can be changed by
MODE SELECT is set to 1; otherwise, the bits are set to 0.
10b = Report default values. Returns the power-up, or reset, values.
11b = Report saved values. Returns the power-up, or reset, values.
Page
Code
2 0-5
The Page Code selects the page or pages to be returned by the
drive.
00h = Return only the Parameter List Header/Block Descriptor
02h = Return the Disconnect/Reconnect Page
0Ah = Return the Control Mode Page
0Fh = Return the Data Compression Control Page
10h = Return the Device Configuration Page
18h = Return the Protocol-Specific Logical Unit Mode Page (FC or
SAS drives only)
19h = Return the Protocol-Specific Port Mode Page (FC or SAS
drives only)
1Ch = Return the Information Exceptions Page
1Dh = Return the Medium Configuration Page
21h = Return the Drive Capabilities Page
22h = Return the Interface Control Page
3Fh = Return all available pages in ascending order starting from
page 02h
Allocation
Length
4 Specifies the number of bytes the host has allocated for returned
MODE SENSE data. The drive will not return more than this amount
of data. A value of 0 is a valid entry and indicates no data.
Reserved
All reserved bits must be 0.
Control
5 See
SCSI Command Control Byte Format on page 25.
Summary of Contents for LTO 4
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