MACH16
S
LIM
L
ITE
3Gbps
SATA
S
TANDARD
S
OLID
-S
TATE
D
RIVE
P
ART
N
UMBER
:
M16SD2S(3)-
XXX
U(T)(X)-XXX
D
OCUMENT
N
UMBER
:
61000-07132-311
R
EVISION
N
UMBER
:
3.11
R
EVISION
D
ATE
:
01/15/2013
88
S.M.A.R.T.
C
OMMAND
T
RANSPORT
The implementation of the S.M.A.R.T. Command Transport (SCT) feature set provides a method of
communication between host systems and ATA devices in bridged environments. Increasingly, PATA and
SATA devices are being bridged across different bus types. A specific bridge, due to design limitations,
may not be able to pass commands and data between the host system and ATA device. SCT is therefore
implemented to facilitate the exchange commands and data between systems in a bridged environment
using S.M.A.R.T.
and extended logs. SCT commands are “pass-through” commands, i.e., the commands
are “piggy-backed” onto standard ATA commands. For example, if a command is passed using WRITE
LOG (D5h) over the bridge, then the ATA device can parse the log entry and execute the command.
It is recommended that the user reference
T13 1701DT-N,
Revision 5, February 24, 2005
for more information.
SCT
C
OMMAND
F
ORMAT
A SCT command (Key Sector) is 512 bytes in length. The host will query the status of a SCT command to
determine if it is active, complete, or terminated due to an error. Table 15 defines the generic format of an
SCT command written to the SCT Command/Status log.
Table 15: SCT Command Format
B
YTE
F
IELD
W
ORDS
D
ESCRIPTION
0-1
Action Code
1
This field defines the command type and the
type of data being accessed, such as
sector
,
long sector
, etc., or the action being executed.
2-3
Function Code
1
This field specifies the type of access and
varies by command. For example, it could
specify read, write, verify, etc.
4-x
Parameter 1
Depends on command. Depends on command.
x+1..y
Parameter 2
Depends on command. Depends on command.
.
.
.
…
.
.
.
.
.
.
Total Words
256
