Sony SDX-700C, Product Specifications Manual

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REQUEST SENSE 6.Command Specification
SONY AIT-3 drive SDX-700 series Ver.2.1 6-91
Information Bytes : The conditions of these bytes will contain the differences (residue) of the requested length
minus the actual length in either bytes, blocks, File-marks or Set-marks as determined by the command. (Negative
values are indicated by two’s complement notation.) These bytes will be valid for all READ, WRITE, SPACE and
VERIFY commands for which a CHECK CONDITION status has been generated. These bytes will be ZERO for
MODE SELECT/SENSE, INQUIRY, READ BLOCK LIMITS and TEST UNIT READY commands.
Additional Sense Length : This specifies the number of additional sense bytes that are to follow. If the Allocation
Length of the Command Descriptor Block is too small to transfer all of the additional sense bytes, the Additional
Sense Length is not adjusted to reflect the truncation.
Command Specific Information Bytes : Command Specific Bytes are unused, and will be ZERO.
Additional Sense Code and Additional Sense Code Qualifier : These two bytes provide additional information
about what caused the CHECK CONDITION status. They are used extensively by the drive. The information is
presented in the Sense Key Description table on the following pages.
Field Replaceable Unit Code : This byte is used to define a device specific mechanism or part that has failed. A
value of ZERO indicates that no specific mechanism or unit has been identified to have failed.
The units and their values are:
00h - Unable to identify failed unit
01h - Drive Mechanism
02h - Drive Electronics
Sense Key specific bytes : These fields will contain data that further defines the nature of the CHECK CONDITION.
If the sense field is set to ILLEGAL REQUEST and the SKSV bit is set to one, the Sense Key specific fields will be as
shown below. The fields point to illegal parameters sent by the Host.
Table 6-71: Field Pointer Bytes
Bit
Byte
7 6 5 4 3 2 1 0
15 SKSV(1) C/D Reserved Reserved BPV Bit Pointer
16 (MSB) Field Pointer
17 (LSB)
C/D : When this bit is set, it indicates that the illegal parameter is in the Command Descriptor Block. A C/D of ZERO
indicates that the illegal parameter is in the Parameter List sent by the Host during the DATA OUT phase.
BPV : When the Bit Pointer Valid bit is set, indicates that the Bit Pointer field specifies which bit of the byte designated
by the Field Pointer is in error. When a multiple-bit field is in error, the Bit Pointer field points to the most significant
(left most) bit of the field.
Field Pointer : This field indicates which byte of the Command Descriptor Block or of the Parameter List data was in
error. Bytes are numbered from ZERO. When a multiple byte field is in error, the pointer points to the most
significant byte of the field.
If the SKSV bit is ZERO, then the Field Pointer Bytes take the Sony Unique Format as shown below:
Table 6-72: Error Code and Status Bytes
Bit
Byte
7 6 5 4 3 2 1 0
15 SKSV(0) Reserved
16 Runtime Error Code
17 Status Byte (00h)
Runtime Error Code : This field is part of the internal protocol and contains the Runtime (error set 0) Error code.
These internal error codes are also listed below, showing to which Sense, ASC and ASCQ fields they are mapped.
Status Byte : This field is not supported. The drive will always return 00h in this byte.