Product manual

3.4.13.2 Mode sense data
The Mode Sense parameter list contains a 4-byte header followed by a
8-byte block descriptor (if any), followed by the mode pages. The header
and block descriptor are shown below. The mode pages are described
in Appendix C.
Bit
Byte
7 6 5 4 3 2 1 0
0 Mode sense data length
1 (default) Medium type (00
H
)
2 WP=0 Reserved
3 (default) Block descriptor length (08
H
)
Block descriptor
4 (default) Density code (00
H
)
5–7 Number of blocks
8 (default) Reserved (00
H
)
9–11 Block length
Mode pages
12–
n Mode pages
Byte 0 The
mode sense data length specifies the number of
bytes minus 1 of the Mode Sense data to be transferred
to the initiator.
Byte 1 The
medium type is always 0.
Byte 2 The
WP (write protect) bit is always 0, which means the
media is write-enabled.
Byte 3 The
block descriptor length is the number of bytes in the
block descriptor. This value does not include the page
headers and mode pages that follow the block descriptor,
if any.
Byte 4 The
density code is not supported.
Bytes 5–7 The
number of blocks field contains the total number of
blocks available to the user, which is specified on page 1.
Byte 8 Reserved.
Bytes 9–11 The
block length is specifies the number of bytes con-
tained in each logical block described by the block de-
scriptor.
56 ST3655 Family SCSI Drives Product Manual, Rev. A