Optical Drive and Library SCSI-2 Command Reference

SCSI-2 Drive Command Set
Mode Sense (Group 2) Command (5AH)
Chapter 2 2-125
SCSI-2 Drive Commands
Mode Sense (Group 2) Command (5AH)
DBD A disable block descriptors (DBD) bit of 0 (default)
indicates that block descriptors are provided.
PC Page control defines the type of parameter values to be
returned as follows:
00 - Current Values
01 - Changeable Values
10 - Default Values
11 - Saved Values
Page Code Page code values are the same as for the Mode Select
(Group 0) command. If the page code is specified as 00H
or 3FH, all the pages are returned.
Allocation
Length Indicates the number of bytes that the indicator has
allocated for return of this data. A length of 0 indicates
that no data will be returned. This condition is not
considered an error. The drive will terminate the data -
in phase when the allocation length has been
transferred or when all available data has been
transferred to the initiator, whichever is less.
Table 2-119 Mode Select (Group 2) Command CDB
Byte 7 6 5 4 3 2 1 0
0 Operation Code (5AH)
1 Logical Unit Number
(0)
Rsvd
(0)
DBD Reserved (0)
2 PC Page Code
3-6 Reserved (0)
7 Allocation Length (MSByte)
8 Allocation Length (LSByte)
9 Reserved (0) Flag Link