INQUIRY
7. ATAPI Packet Command Specification
SONY AIT-1 Turbo drive SDX-470V series Ver.1.0
7-3
7.2. INQUIRY
12h
Bit
Byte
7 6 5 4 3 2 1 0
0
Operation Code (12h)
1
Reserved CmdDT
EVPD
2
Page or Operation Code
3
Reserved
4
Allocation Length
5
Reserved
6
Reserved
7
Reserved
8
Reserved
9
Reserved
10
Reserved
11
Reserved
The INQUIRY command requests that information regarding parameters of the Device be sent to the Host. An
option allows the Host to request additional information about the Device.
CmdDT:
The Command support data
(CmDT)
bit of one specifies that the drive returns the optional support data
specified by the operation code field.
If both the
CmDT
and
EVPD
bits are zero, the drive returns the standard INQUIRY data. If the page or operation
code field is not zero when both
CmdDT
and
EVPD
are zero, the drive returns a CHECK CONDITION status with
an ILLEGAL REQUEST Sense Key.
If the
CmdDT
and
EVPD
bits are one, the drive returns a CHECK CONDITION status with an ILLEGAL REQUEST
Sense Key.
When the
EVPD
bit is set to one, the drive returns vital product data that is specified in the page or operation code
field. If the page or operation code field is reserved or not implemented by the target, the target shall terminate the
command with a CHECK CONDITION status. The sense key shall be set to ILLEGAL REQUEST.
When the
CmdDT
bit is set to one, the page or operation field specifies the operation code for which the drive
shall return support data.
EVPD:
The Enable Vital Product Data
(EVPD)
bit of one specifies that the drive returns the optional vital product
data specified by the page code field.
Allocation Length:
This specifies the maximum number of bytes that the host has allocated for returned Inquiry
data. An Allocation Length of ZERO indicates that no Inquiry data is transferred. This condition is not considered
an error. The drive will terminate the data transfer when Allocation Length bytes have been transferred or when all
available Inquiry data have been transferred to the host, whichever is less.
The INQUIRY command shall return “Check Condition” status only when the Device cannot return the requested
INQUIRY data. The INQUIRY data should be returned even though the Device may not be ready for other
commands.
If an INQUIRY command is received with a pending unit attention condition (i.e. before the Device reports “Check
Condition” status), the Device shall perform the INQUIRY command and shall not clear the unit attention condition.
