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10.18.2.1.3 Key Sector Format
An SCT command (Key Sector) is always 512 bytes long. Table below shows the generic format of an SCT command.
Table 44 Key Sector Format
Byte
Field
Words
Description
1:0
Action Code
1
This field defines the command type and
generally specifies the type of data being
accessed, such as sector or physical action
being performed, such as seek.
3:2
Function Code
1
This field specifies the type of access and varies
by command. For example, this can specify
read, write, verify, etc.
X:4
Parameter1
Depends on command
Depends on command
Y:x+1
Parameter2
Depends on command
Depends on command
…
…
…
…
Total Words
256
The action codes are defined in Table below.
Table 45 SCT Action Code List
Action Code
Block Data
TF Data
Description
0000h
-
-
Reserved
0001h
Read/Write
Y
Long Sector Access (Not Supported)
0002h
Write
N
SCT Write Same
0003h
-
Y
Error Recovery Control
0004h
-
Y
Features Control
0005h
Read
N
SCT Data Table
0006h-BFFFh
-
-
Reserved
C000h-FFFFh
-
-
Vendor Specific
88
Hard Disk Drive Specification