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SCSI Interface Product Manual, Rev. J
Table 88:
Mode Sense Data
Bit
7
Byte
0
Sense Data Length [1]
1
0
2
WP [3]
3
0
0
Density Code (MSB) [5] [6]
1
Number of Blocks (MSB) [6]
2
Number of Blocks [6]
3
Number of Blocks (LSB) [6]
4
0
5
Block Length (MSB) [7]
6
Block Length [7]
7
Block Length (LSB) [7]
0-n
Mode Sense Page Headers and Their Parameters
Notes.
[1]
The Sense Data Length specifies the length in bytes of the following Mode Sense data that is available to
be transferred during the Data In phase. The Sense Data Length does not include itself.
[2]
The drive supports only 00h (default medium) in the Medium Type field.
[3]
A Write Protect (WP) bit of zero indicates the medium is write enabled. A WP bit of one indicates the
medium is write protected.
[4]
The Block Descriptor Length specifies the length in bytes of the Block Descriptor. It is equal to the number
of bytes in the Block Descriptor (8) and does not include the page headers and mode parameters, if any.
The drive sends one Block Descriptor.
Each Block Descriptor specifies the medium characteristics for all or part of a logical unit. Each Block
Descriptor contains a Density Code, a Number of Blocks, and a Block Length.
[5]
a. Drives that do not support capacity programming have only 00h (default density) in the Density Code
field.
b. Drives that support capacity programming may have a value in this field that states either the logical or
actual capacity of the drive.
[6]
a. For drives that do not support capacity programming, the Number of Blocks field specifies the number
of logical blocks of the medium that meets the Density Code and Block Length in the Block Descriptor.
A Number of Blocks of zero indicates that all of the remaining logical blocks of the logical unit have the
medium characteristics specified by the Block Descriptor.
b. For drives that have capacity programming capability, these bytes do not report back the drive capacity
on some models. These bytes are always zero on those models. Some models do report drive capac-
ity in bytes 0, 1, 2, and 3, so those bytes will be nonzero. See individual drive's Product Manual, Vol-
ume 1, for the drive of interest.
6
5
0
0
0
0
DPO-FUA
Reserved
0
0
Block Descriptor Length (8 decimal) [4]
Block Descriptor Data
0
0
Parameter Information
4
3
0
0
Medium Type [2]
0
[8]
0
1
0
0
Reserved
2
1
0
0
0
0
Reserved
0
0
0
0
121
0
0
0
0
0
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