Fujitsu M2488, Руководство по эксплуатации продукта

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TAPE UNIT SCSI COMMANDS M2488 PRODUCT GUIDE
4-56 CG00000-011503 REV. A April 1997
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
0
The Disable Block Descriptor (DBD) bit value of 1 specifies that no block
descriptor is returned in the MODE SENSE data.
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.