5.32.2Status Reporting

The drive returns CHECK CONDITION status for a REQUEST SENSE command only to report errors specific to the command when:

•A non-zero reserved bit is detected in the Command Descriptor Block.

•A drive malfunction prevents return of the sense data.

For Parallel SCSI disk drives, the drive also returns CHECK CONDITION status for a REQUEST SENSE command to report errors specific to the command when an unrecovered parity error is detected on the data bus.

Note that any of the previous conditions overwrites the current sense data with the sense data describing the error encountered by the REQUEST SENSE command (that is, for the condition stated in the first bulleted entry, the new sense data reflects that a non-zero reserved bit was detected in the Command Descriptor Block).

The drive returns a maximum of 18 bytes of sense data. The initiator should set the Allocation Length field in the Command Descriptor Block to 18 to receive all sense data. If the Allocation Length is set to 0, four bytes of data will be returned (this option maintains compatibility with SCSI-1 systems).

5.32.3Sense Data Format for Error Code 70h and Error Code 71h

The sense data format for error code 70h (current error) and error code 71h (deferred error) is shown in Table 5-168;the data fields are defined in Table 5-169.The Supported Sense Keys are described in Table 5-170and the field contents in Table 5-

171.The Supported Additional Sense Codes and Sense Code Qualifiers are described in Table 5-172and the Sense-Key Specific Field Contents in Table 5-173.

Table 5-168Sense Data Format for Error Code 70h or 71h-Data Format

Bit

7

6

5

 

4

 

3

 

2

 

1

0

Byte

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0

Valid

 

 

 

Error

Code (70h or

71h)

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

 

 

 

Segment Number = 00h

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

FileMrk

EOM

ILI

 

Rsvd

 

 

 

Sense Key

 

 

 

= 0

= 0

 

 

 

 

 

 

 

 

 

 

3 - 6

 

 

 

 

Information

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

7

 

 

 

Additional Sense Length = 0Ah

 

 

 

 

 

 

 

 

 

 

 

 

 

8 - 11

 

 

 

Command-Specific Information

 

 

 

 

 

 

 

 

 

 

 

 

 

 

12

 

 

 

 

Additional Sense Code

 

 

 

 

 

 

 

 

 

 

 

 

 

13

 

 

 

Additional Sense Code Qualifier

 

 

 

 

 

 

 

 

 

 

 

 

 

14

 

 

 

Field Replaceable Unit Code

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

15

SKSV

 

 

 

Sense-Key Specific

 

 

 

 

 

 

 

 

 

 

 

 

 

16 - 17

 

 

 

Sense-Key Specific (continued)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Maxtor Atlas 10K V

5-115