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Western Digital Hard Disk Drive OEM Specification
9.18.2 SCT Command Protocol
9.18.2.1 Command Transport
SCT Command Transport occurs when a 512-byte data packet (called “Key Sector”) is created and the written to
SMART or extended log page E0h. The key sector specifies Action and Function Codes along with the parameters
that are required to perform the action.
9.18.2.1.1 Issue SCT Command Using SMART
Command Block Output Registers
Table 47 Output Registers of SCT Command Using SMART
Command Block Input Registers (Success)
Command Block Input Registers (Error)
Extended Status code
(LSB)
Extended Status code
(MSB)
Number of sectors to
transfer (LSB)
Number of sectors to
transfer (LSB)
Number of sectors to
transfer (MSB)
Number of sectors to
transfer (MSB)
Table 48 Input Registers of SCT Command Using SMART