Fujitsu M2488 Mode Sense command 1Ah, Mode Sense CDB Description, Mode Sense Field Description

TAPE UNIT SCSI COMMANDS M2488 PRODUCT GUIDE

4-3.13 MODE SENSE command 1Ah

The MODE SENSE command provides a means for a target to report its medium, logical unit, or peripheral device parameters to the initiator by sending the parameters during the data phase of this command. The MODE SENSE command is a complementary command to the MODE SELECT command.

4-3.13.1 MODE SENSE CDB Description

MODE SENSE is a six-byte command. The bytes are shown below and described in Table 4-51. Common fields are described in paragraph 4-3.1 on page 4-4.

							BITS
BYTES	7		6	5		4		3		2	1		0
0	0		0	0		1		1		0	1		0
1
			LUN			Reserved		DBD			Reserved
2
		PC							Page Code
3							Reserved
4
							Allocation Length
5
					Reserved							Flag		Link

Note: Changeable fields in the CDB are shaded.

Table 4-51. MODE SENSE Field Description

BYTE	BIT	VALUE	DESCRIPTION
0	0-7	1Ah	Operation code.
1	3	1	The Disable Block Descriptor (DBD) bit value of 1 specifies that no block
			descriptor is returned in the MODE SENSE data.
		0	When this bit is set to 0, the target will return a block descriptor in the MODE
			SENSE data.
2	0-5		The Page Code allows the initiator to select any one specific page or all of the
			pages supported by a target. Pages are used to set and return device parameters.
			Refer to the Page Code descriptions in Table 5-1 on page 5-1.
2	6-7		The Page Control (PC) field indicates the type of page parameter values to be
			returned by the target. The PC field is defined in Table 4-52.
4	0-7		The Allocation Length specifies the number of bytes the initiator has allocated
			for returned Mode Sense data. An Allocation Length of 00h indicates no Mode
			Sense data is to be transferred; this condition is not considered an error.

4-56 CG00000-011503 REV. A April 1997