Western Digital Ultrastar DC HC310, Specifications

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Western Digital Hard Disk Drive OEM Specification
9.18.2.1.3 Key Sector Format
An SCT command (Key Sector) is always 512 bytes long. Table below shows the generic format of an SCT
command.
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
Table 51 Key Sector Format
The action codes are defined in Table below.
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
Table 52 SCT Action Code List