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SCSI Description
5.21
READ (10) Command (28h)
The READ (10) command requests that data be transferred from the drive to the
initiator. The amount of data transferred is specified by the transfer length field. The
starting point is specified by the logical sector address. The data format and field
descriptions are shown in Table 5-124 and Table 5-125 respectively.
Bit
Byte
0
1
2 - 5
6
7 - 8
9
Table 5-125
Field
DPO
FUA
RelAdr
Logical Block Address
Transfer Length
5-94
Maxtor Atlas 15K
READ (10) Command-Data Format
Table 5-124
7
6
5
Reserved
READ (10) Command-Field Descriptions
Disable Page Out. When the value is 0, the drive caches the data read, using its normal
Logical Read Unit policies.
When the value is 1, the drive assigns to logical blocks accessed by the READ (10)
command the lowest priority for being fetched into or retained by the cache.
Force Unit Access. When the value is 0, the drive is allowed to satisfy the read with
cache-resident data.
A value of 1 indicates that the drive accesses the media in performing the command
before returning GOOD status.
Relative Addressing. The drive does not support relative addressing. Must be 0
Specifies the logical sector address where the read operation will begin.
Specifies the number of contiguous logical blocks of data to transfer. A transfer length
of 0 indicates that no logical blocks are to be transferred.
Any other value indicates the number of logical blocks to be transferred. The drive
returns a CHECK CONDITION status with the correct sense data if the specified
transfer extends beyond the logical sector space.
4
3
2
Operation Code (28h)
DPO
FUA
Logical Block Address
Reserved
Transfer Length
Control
Description
1
0
Reserved
RelAdr
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