SCSI Description
￿￿￿￿4'#&￿￿￿￿￿￿%QOOCPF￿￿￿￿J￿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 5-127and Table 5-128respectively.
READ (10) Command-Data Format

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0

 

 

 

 

Operation Code (28h)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

 

 

Reserved

 

DPO

 

FUA

 

Reserved

 

RelAdr

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2 - 5

 

 

 

 

Logical Block Address

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

6

 

 

 

 

 

Reserved

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

7 - 8

 

 

 

 

 

Transfer Length

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

9

 

 

 

 

 

Control

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

$[VG$KV

 

￿

 

￿￿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.

 

 

 

 

 

(KGNFDPO ￿

 

 

When the value is 1, the drive&GUETKRVKQPassigns 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.

 

 

 

 

 

 

 

 

FUA

 

Table5-127

 

 

 

 

 

 

 

 

 

 

 

 

 

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.

 

 

 

 

 

 

 

 

 

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.

Transfer Length

 

 

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.

 

 

 

Table5-128

 

 

 

 

 

 

 

 

 

Maxtor Atlas 10K III

5-107

Page 171
Image 171
Maxtor 10K III manual Operation Code 28h Reserved, Dpo Fua, Reserved RelAdr Logical Block Address, Transfer Length Control