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
76543210
0Sense Data Length
100000000
Reserved
2WP 00
DPO-FUA 0000
Reserved Reserve d
300000000
Block Descriptor Length (8 decimal)
Block descriptor data
000000000
Number of Blocks (MSB)
100000000
Number of Blocks
200000000
Number of Blocks
300000000
Number of Blocks (LSB)
400000000
Reserved
5Block Length (MSB)
6Block Length
7Block Length (LSB)
Parameter information
0–n Mode Sense Page Headers and Their Parameters
Table
number
143
143
143