SCS I Description
M axtor Atlas 10K III 5-107
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 5-127 and Table 5-128 respectively.
READ (10) Command-Data Format
READ (10) Command-Field Descriptions
0 Opera tion C ode (2 8h )
1 Reserved DPO FUA Reserved RelAdr
2 - 5 Logical Block Address
6 Reserved
7 - 8 Transfer Len g th
9 Control
DPO
Disable Page Out. When the value is 0, the drive caches the data read,
using i ts normal Logical Read Unit policies.
When the value is 1, the drive assigns to logical bl ocks ac cessed by the
READ (10) command the lowest priority for being fetched into or retained
by the cache.
FUA
Force U nit Access . Whe n the val ue is 0, th e driv e is allowed to satis fy the
read w it h cache-resident data.
A valu e of 1 ind icates th at the dri ve acce sses the media i n perform ing the
command before re tur ning GOOD stat us.
RelAdr Relative Addressing. The drive does not support relative addressing. Must
be 0
Logical Block Address Spe cif ies the logical sector address w here the read operation will begin.
Transfer Length
Specifies the number of conti guous logical blocks of data to transf er. A
trans fer leng th of 0 indic ates that no l ogical blocks are to be transf erred.
Any othe r value i ndi cates t he number of logica l bl ocks to be trans ferred.
The drive returns a CHECK CONDITION status with the correct sense data
if th e specified transfer extends beyond the logical sector space .