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SONY SDT-10000/SDT-11000 DDS Tape Drive
6. COMMAND SPECIFICATION
ILI: This is the Incorrect Length Indicator bit, which indicates that the requested logical block length did not match the
logical block length of the data on the medium. Only READ or VERIFY may cause this bit to be set.
Information Bytes:
The conditions of these bytes will contain the differences (residue) of the requested length minus the actual length in
either bytes, blocks, Filemarks or Setmarks 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.
Bit
7
6
5
4
3
2
1
0
Byte
15
SKSV(1)
C/D
Reserved
Reserved
BPV
Bit Pointer
16
(MSB)
Field Pointer
17
(LSB)
Table 6-48: Field Pointer Bytes
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.
REQUEST SENSE
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