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Quantum 10K II User Manual

Page 214

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SCSI Description

Quantum Atlas 10K II Ultra160/m SCSI Hard Disk Drives

5–147

5.25

READ DEFECT DATA Command (12) (B7h)

The READ DEFECT DATA (12) command directs the drive to report defect
information about the drive’s medium. Refer to the FORMAT UNIT command for
information about defects. The data sent to the host in the command’s data-in buffer
transfer consists of a four-byte Defect List header (Figure 5-68), followed by any
Defect Descriptors (Figures 5-66 and 5-67).
The READ DEFECT DATA (12) Command Descriptor Block is shown in Figure 5-
65; the data fields are described in Table 5-69.

Bit

Byte

7

6

5

4

3

2

1

0

0

Operation Code (B7h)

1

Reserved

Plist

Glist

Defect List Format

2 - 5

Reserved

6 - 9

(MSB)

Allocation Length

(LSB)

10

Reserved

11

Control

Figure 5–65 READ DEFECT DATA (12) Command — Data Format

Table 5–69 READ DEFECT DATA (12) Command — Field Description

Field

Description

PList

When the value is 0, the returned data does not include the Primary Defect
List.
When the value is 1, the returned data includes the Primary Defect List. The
defects are returned in ascending order.

GList

When the value is 0, the returned data does not include the Grown Defect
List.
When the value is 1, the returned data includes the Grown Defect List. The
defects are returned in order of occurance.
When both PList and GList are set to 1, the Primary Defect List and the
Grown Defect List are returned. The Plist is returned followed by the Glist
(the lists are not merged). When both are set to 0, only the Defect List
Header (Figure 5-68) is reported to the initiator.

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