7K200 SATA OEM Specification
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12.17
SMART Command Transport (SCT)
SMART Command Transport (SCT) feature set is supported. The SMART Read Log and SMART
Write Log commands or Read Log Ext and Write Log Ext commands are used to issue a command in
this feature sets. Log page E0h is used to issue commands and return status. Log page E1h is
used to transport data. Please refer to the section 8 SCT Command Transport in ATA8-ACS
specification for more detail.
The following Action codes are supported.
Action
code
Description
0002h Write
Same
command
0003h
Error Recovery Control command
Feature Control command
Feature code
0001h
Write Cache
0004h
Feature code
0003h
Time Interval for temperature logging
0005h
SCT Data Table command
Table 39 SCT Action Code Supported
13
Command Protocol
The commands are grouped into different classes according to the protocols followed for command
execution. The command classes with their associated protocols are defined below.
Please refer to Serial ATA Revision 2.6 (Section 11. device command layer protocol) about each
protocol.
For all commands, the host must first check if BSY=1, and should proceed no further unless and
until BSY=0. For all commands, the host must also wait for RDY=1 before proceeding.
A device must maintain either BSY=1 or DRQ=1 at all times until the command is completed. The
INTRQ signal is used by the device to signal most, but not all, times when the BSY bit is changed
from 1 to 0 during command execution.
A command shall only be interrupted with a COMRESET or software reset. The result of writing to
the Command register while BSY=1 or DRQ=1 is unpredictable and may result in data corruption. A
command should only be interrupted by a reset at times when the host thinks there may be a
problem, such as a device that is no longer responding.
Interrupts are cleared when the host reads the Status Register, issues a reset, or writes to the
Command Register.
“Table 138 Timeout Values” on Page 171 shows the device timeout values.