DISK DRIVE OPERATION

6.4.25 Standby (96h, E2h)

This command causes the drive to enter Standby Mode. See 6.6.3 for the protocol. The drive may return the interrupt before the transition to Standby Mode is completed.

If the drive is already spun down, the spin down sequence is not executed.

6.4.26 Standby Immediate (94h, E0h)

This command causes the drive to enter Standby Mode. See 6.6.3 for the protocol. The drive may return the interrupt before the transition to Standby Mode is completed.

If the drive is already spun down, the spin down sequence is not executed.

6.4.27 Write Buffer (E8h)

This command enables the host to overwrite the contents of the drive's sector buffer with any data pattern desired. See 6.6.2 for the protocol.

The Read Buffer and Write Buffer commands shall be synchronized within the drive such that sequential Write Buffer and Read Buffer commands access the same 512 bytes within the buffer.

6.4.28Write Long (32h:with retry, 33h:without retry)

This command is similar to the Write Sectors command, except that it writes the data and the ECC bytes directly from the sector buffer; the drive does not generate the ECC bytes itself. Only single sector Write Long operations are supported.

The transfer of the ECC bytes shall be 8 bits wide, and 4 or device native ECC bytes length.

6.4.29 Write DMA (CAh)

This command executes in a similar manner to Write Sector(s) except for the following:

The host initializes a slave-DMA channel prior to issuing the command

Data transfers are qualified by DMARQ and are performed by the slave-DMA channel

The drive issues only one interrupt per command to indicate that data transfer has terminated and status is available.

Any error encountered during Write DMA execution results in the termination of data transfer. The drive issues an interrupt to indicate that data transfer has terminated and the status is available in the Error register. The error posting is the same as that for the Write Sector(s) command.

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SpinPoint V40 Product Manual

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Samsung spinpoint v40, 3.5 hard disk drives Standby 96h, E2h, Standby Immediate 94h, E0h, Write Buffer E8h, Write DMA CAh