Samsung M8-DVR manual Set Features Register Definitions, Transfer Mode Values

	Table 8-11 Set Features Register Definitions
Code	Description
02h	Enable Write Cache
03h	Set transfer mode based on value in Sector Count register
06h	Enable Power-Up in Standby Mode
07h	Power-Up in Standby feature set device spin up
10h	Enable use of SATA features
	SC=02: DMA Setup FIS Auto Activate automation
	SC=03: Device-initiated interface power state transition
	SC=06: Software Settings Preservation
44h	Obsolete (Set VU ECC length)
55h	Disable read look-ahead feature
82h	Disable Write Cache
86h	Disable Power-Up in Standby Mode
90h	Disable use of SATA features
	SC=02: DMA Setup FIS Auto Activate automation
	SC=03: Device-initiated interface power state transition
	SC=06: Software Settings Preservation
AAh	Enable read look-ahead feature
BBh	Obsolete (Set 4-byte ECC length)
D2h-DFh	VU Features
F0h-FFh	VU Features

When the drive receives this command, it checks the contents of the Feature register, clears BSY, and generates an interrupt. If the value in the Feature register is not supported or is invalid, the drive posts an Aborted Command error.

A host can choose the transfer mechanism by Set Transfer Mode and specifying a value in the Sector Count register in feature 03. The upper 5 bits define the type of transfer, and the low order 3 bits encode the mode value. Refer to the following table for details.

Table 8-12 Transfer Mode Values

Mode	Bits(7:3)	Bits(2:0)
PIO default mode	00000	000
PIO default mode, disable IORDY	00000	001
PIO flow control transfer mode	00001	mode
Multiword DMA mode	00100	mode
Ultra DMA mode	01000	mode

Mode = transfer mode number

Spinpoint M8-DVR Disti Product Manual REV 2.0 62