User's Guide

Commands: Inquiry (12h) Page 41
INQUIRY (12h)
The INQUIRY command requests that the drive return parameter information. If an
INQUIRY command is received from an Initiator with a pending Unit Attention
Condition (before the drive reports Check Condition status), the drive performs the
INQUIRY command and does not clear the Unit Attention Condition.
INQUIRY Command Descriptor Block
The following table shows the layout of the CDB.
B
yt
e
Bits
7 6 5 4 3 2 1 0
0 0 0 0 1 0 0 1 0
1 0 0 0 0 0 0 0 EVPD
2 Page Code
3 0 0 0 0 0 0 0 0
4 Allocation Length
5 vendor unique* 0 0 0 0 Flag Link
* This vendor-unique field is reserved and must be set to zero.
Command Descriptor Block Field Description
The following table defines the fields in the CDB.
Field Name Bytes Bits Description
EVPD 1 0 An Enable Vita Product Data (EVPD) bit of 1 specifies that
the drive return vital product data specified in the Page Code
field. An EVPD bit of 0 specifies that the drive return the
standard INQUIRY data.
Page Code 2 The Page Code field specifies which page of vital product
data information the target returns.
Allocation
Length
4 This field specifies the number of bytes that the Initiator
allocated for the response data. The drive transfers the
number of bytes specified up to a maximum of 36. An
Allocation Length of zero indicates that no data can be
transferred. This length is not considered an error.