Hitachi Ultrastar 15K450 (FC-AL) Hard Disk Drive Specification
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19.23 READ DEFECT DATA (37)Table 188:READ DEFECT DATA (37)
The READ DEFECT DATA command requests that the Target transfer the medium defect data to the Initiator.
If the Target is unable to access any medium defect data it will return a Check Condition status with the appropriate sense
key. The sense key will be set to either Medium Error (03h) if a medium error occurred or No Sense (00h) if the list does not
exist and the additional sense code will be set to Defect List Error (19h).
•Plist bit set to one indicates that the Target returns the Plist. A Plist bit of zero indicates that the Target shall not return
the Plist of defects.
•Glist bit set to one indicates that the Target returns the Glist. A Glist bit of zero indicates that the Target shall not
return the Glist.
Note: With both bits set to one Plist and Glist the Target will return both the primary and grown defect lists. With
both bits set to zero, the Target will return only a 4-byte Defect List Header.
•Defect List format field is used by the Initiator to indicate the preferred format for the defect list.
The Defect List Format of '100 (Bytes from Index Format)' and '101 (Physical Sector Format)' are supported. If the
requested format is not supported by the drive, it will return the defect list in its default format '101' and then termi-
nate the command with Check Condition status. The sense key will be set to Recovered Error (01h) and the addi-
tional sense code will be set to Defect List Not Found (1Ch).
The drive sends defect list (Defect Descriptors) in a 8-byte Absolute Block Address (ABA) format that follows a four byte
Defect List Header.
The Target will transfer all of the Read Defect Data up to the number of bytes allocated by the Initiator.
Byte Bit
76543210
0 Command Code = 37h
1 Reserved = 0 Reserved = 0 0
2 Reserved = 0 Plist Glist Defect List Format
3-6 Reserved = 0
7-8 (MSB) Allocation Length
(LSB)
9 VU = 0 Reserved = 0 FLAG LINK