Read Defect Data Command (37 H ) - Seagate ST3285N Product Manual

68 ST3655 Family SCSI Drives Product Manual, Rev. A
3.5.7 Read Defect Data command (37
When the drive receives this command, it reads the defect data off its
reserved cylinders and transfers the defect data to the initiator.
The initiator can use this command to do a Format Unit command. It
reads the defect lists off the reserved cylinders and resends the lists as
defect data without changing them.
The Read Defect Data command can be used to access two types of
defect lists, the P-list and the G-list. These lists are described in Sec-
tion 3.4.4.1.
Bit
7 6
Byte
0 0 0
1 LUN
2 0 0
3 0 0
4 0 0
5 0 0
6 0 0
7–8
9 0 0
Byte 2 If the P-list bit is 1, the drive sends the primary defect list. If
the P-list bit is 0, the drive does not send the primary defect
list. If the G-list bit is 1, the drive sends the grown defect list.
If the G-list bit is 0, the drive does not send the grown defect
list. If both the P-list and G-list bits are zero, the drive returns
the defect list header only.
If the defect list format field contains 100, the drive returns
the defect data in the bytes-from-index format. If the defect
list format field contains 101, the drive returns the defect
data in the physical sector format. If the defect list format
field contains 000, the drive returns the defect data in the
default format, which is the physical sector format, and
generates a check condition status.
Bytes 7–8 The allocation length specifies the number of bytes the
initiator has allocated for the returned defect data. An
allocation length of 0 indicates that no defect data is trans-
ferred. Any other value indicates the maximum number of
bytes to be transferred. The data in phase ends when the
)
H
5 4 3 2
1 1 0 1
0 0 0
0 P-list G-list Defect list format
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
Allocation length
0 0 0 0
1 0
1 1
0 0
0 0
0 0
0 0
0 0
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