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Maxtor Atlas 10K V 5-93
5.19 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 5-121 and Table 5-122 respectively.
Table 5-121 READ (10) Command-Data Format
Table 5-122 READ (10) Command-Field Descriptions
Bit
Byte
76543 210
0 Operation Code (28h)
1 Reserved DPO FUA Reserved RelAdr
2 - 5 Logical Block Address
6 Reserved
7 - 8 Transfer Length
9 Control
Field Description
DPO
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.
FUA
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.
RelAdr Relative Addressing. The drive does not support relative addressing. Must be 0
Logical Block Address Specifies the logical sector address where the read operation will begin.
Transfer Length
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.