Advanced Configuration and Power Interface Specification

Advanced Configuration and Power Interface Specification
Field Format Description
Flags DWORD Mode flags
Bit [0]: 1 indicates using UltraDMA on drive 0
Bit [1]: 1 indicates IOChannelReady is used on drive 0
Bit [2]: 1 indicates using UltraDMA on drive 1
Bit [3]: 1 indicates IOChannelReady is used on drive 1
Bit [4]: 1 indicates chipset can set timing independently for each drive
Bits [31:5]: reserved (must be 0)
9.8.2.1.2 _STM (Set Timing Mode)
This Control Method sets the IDE channel’s transfer timings to the setting requested. The AML code
is required to convert and set the nanoseconds timing to the appropriate transfer mode settings for
the IDE controller. _STM may also make adjustments so that _GTF control methods return the
correct commands for the current channel settings.
This control method takes three arguments: Channel timing information (as described in Table 9-6),
and the ATA drive ID block for each drive on the channel. The channel timing information is not
guaranteed to be the same values as returned by _GTM; the OS may tune these values as needed.
Arguments: (3)
Arg0 – A Buffer containing a channel timing information block (described in Table 9-6)
Arg1 – A Buffer containing the ATA drive ID block for channel 0
Arg2 – A Buffer containing the ATA drive ID block for channel 1
Return Value:
None
The ATA drive ID block is the raw data returned by the Identify Drive ATA command, which has
the command code “0ECh.” The _STM control method is responsible for correcting for drives that
misreport their timing information.
9.8.3 Serial ATA (SATA) Controller Device
9.8.3.1 Definitions
HBA
Native SATA aware
Host Bus Adapter
Refers to system software (BIOS, option ROM, operating system,
etc) that comprehends a particular SATA HBA implementation
and understands its programming interface and power
management behavior.
Non-native SATA aware Refers to system software (BIOS, option ROM, operating system,
etc) that does not comprehend a particular SATA HBA
implementation and does not understand its programming
interface or power management behavior. Typically, non-native
SATA aware software will use a SATA HBA’s emulation
interface (e.g. task file registers) to control the HBA and access
its devices.
512 April, 2015 Version 6.0