Seagate Fibre Channel Interface User Manual
Page 227
Fibre Channel Interface Manual, Rev. D
213
Field definitions (listed alphabetically)
Block Descriptor Length
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 disc 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.
Block Length
As defined after a format function, specifies the length (in bytes) of each logical block described by the Block Descriptor.
Default is 512 if no Mode Select command is received before the Format command. The disc drive may be formatted from
180 to 4,096 bytes per sector in multiples of four bytes.
DPO-FUA (Disable Page Out–Force Unit Access)
0
When used with the Mode Sense command, the target does not contain a cache memory or does not support the
DPO and FUA bits.
1
The target supports the DPO and FUA bits.
Table 143: Mode Sense (6) parameter list
Bit
Byte
7
6
5
4
3
2
1
0
0
Sense Data Length
1
0
0
0
0
0
0
0
0
Reserved
2
WP
0
0
DPO-FUA
0
0
0
0
Reserved
Reserved
3
0
0
0
0
0
0
0
0
Block Descriptor Length (8 decimal)
Block descriptor data
0
0
0
0
0
0
0
0
0
Number of Blocks (MSB)
1
0
0
0
0
0
0
0
0
Number of Blocks
2
0
0
0
0
0
0
0
0
Number of Blocks
3
0
0
0
0
0
0
0
0
Number of Blocks (LSB)
4
0
0
0
0
0
0
0
0
Reserved
5
Block Length (MSB)
6
Block Length
7
Block Length (LSB)
Parameter information
0–n
Mode Sense Page Headers and Their Parameters
Table
number