ATAPI Interface Chapter 5
Seagate Travan 40 Product Manual Page 109
SET FEATURES (ATA Command EF)
This command is used by the Host to establish parameters that affect the execution
of certain device features.
At power on, or after a hardware reset, the default setting of the functions specified
by the subcommands are vendor specific. If any subcommand input value is not
supported or is invalid, the device posts an Aborted command error.
Host Taskfile Registers—Inputs
Data Bits
Host Taskfile
Register 7 6 5 4 3 2 1 0 HEX
Features Subcommand code
Sector Count Subcommand specific
Sector
Number Subcommand specific
Byte Count
High Subcommand specific
Byte Count
Low Subcommand specific
Device/Head rsvd LBA rsvd DEV SAM LUN (not used)
Command command EF
Supported Subcommands
Value Description
03h Set transfer mode, based on the value in the Sector Count register.
66h Disable revert to POR values
Set Transfer Mode Values
Mode Bits 7:3 Bits 2:0
PIO default mode 00000b 000b
PIO default mode, disable IORDY (not supported) 00000b 001b
PIO flow control transfer mode 00001b mode
(retired) 00010b N/A
Multiword DMA mode 00100b mode
Ultra DMA mode
(not supported)
01000b mode
Reserved 10000b N/A
Host Taskfile Registers—Outputs
Data Bits