Fujitsu M2488 manual Inquiry command 12h, Inquiry CDB Description, Inquiry Field Description, Evpd

TAPE UNIT SCSI COMMANDS M2488 PRODUCT GUIDE

4-3.6 INQUIRY command 12h

The INQUIRY command provides a means for an initiator to request information regarding parame- ters of the target and any attached peripheral devices.

4-3.6.1 INQUIRY CDB Description

The INQUIRY CDB is a six-byte command. The bytes are shown below and described in Table 4-15. 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			0		0	1		0
1
		LUN							Reserved					EVPD
2
							Page Code
3							Reserved
4
						Allocation Length
5
				Reserved								Flag			Link

Note: Changeable fields in the CDB are shaded.

			Table 4-15. INQUIRY Field Description
BYTE	BIT	VALUE	DESCRIPTION
0	0-7	12h	Operation code.
1	0	1	An Enable Vital Product Data (EVPD) bit of one specifies that the target returns
			the optional Vital Product Data (VPD) specified by the Page Code field. See sec-
			tion 5-3 for the description of the MTU VPD pages or section 6-4 for the
			description of the MC VPD pages supported by the INQUIRY command.The
			EVPD bit and its relationship to the Page Code field is shown in Table 4-16.
		0	An EVPD bit of 0 indicates transfer of normal INQUIRY data.
2	0-7		The Page Code codes are described in Table 4-17.
4	0-7		The Allocation Length field specifies the maximum number of bytes that the initi-
			ator has allocated for returned INQUIRY data. An allocation length of zero indi-
			cates no INQUIRY data is to be transferred. This condition is not considered as an
			error.
			The target terminates the DATA IN phase when allocation length bytes are trans-
			ferred or when all available INQUIRY data is transferred to the initiator, which-
			ever is less. The user should specify an allocation length of at least 68h (104)
			when normal Inquiry data (EVPD=0) is requested.

4-18 CG00000-011503 REV. A April 1997