Advanced Configuration and Power Interface Specification

ACPI-Defined Devices and Device-Specific Objects
9.8.2.1 IDE Controller-specific Objects
9.8.2.1.1 _GTM (Get Timing Mode)
This Control Method exists under each channel device object and returns the current settings for the
IDE channel.
Arguments:
None
Return Value:
A Buffer containing the current IDE channel timing information block as described in Table 9-258
below.
_GTM returns a buffer with the following format
Buffer (){
PIO Speed 0
DMA Speed 0
PIO Speed 1
DMA Speed 1
Flags
}
//DWORD
//DWORD
//DWORD
//DWORD
//DWORD
Table 9-258 GTM Method Result Codes
Field Format Description
PIO Speed 0 DWORD The PIO bus-cycle timing for drive 0 in nanoseconds. 0xFFFFFFFF
indicates that this mode is not supported by the channel. If the chipset
cannot set timing parameters independently for each drive, this field
represents the timing for both drives.
DMA Speed 0 DWORD The DMA bus-cycle for drive 0 timing in nanoseconds. If bit 0 of the Flags
register is set, this DMA timing is for UltraDMA mode, otherwise the timing is
for multi-word DMA mode. 0xFFFFFFFF indicates that this mode is not
supported by the channel. If the chipset cannot set timing parameters
independently for each drive, this field represents the timing for both drives.
PIO Speed 1 DWORD The PIO bus-cycle timing for drive 1 in nanoseconds. 0xFFFFFFFF
indicates that this mode is not supported by the channel. If the chipset
cannot set timing parameters independently for each drive, this field must be
0xFFFFFFFF.
DMA Speed 1 DWORD The DMA bus-cycle timing for drive 1 in nanoseconds. If bit 0 of the Flags
register is set, this DMA timing is for UltraDMA mode, otherwise the timing is
for multi-word DMA mode. 0xFFFFFFFF indicates that this mode is not
supported by the channel. If the chipset cannot set timing parameters
independently for each drive, this field must be 0xFFFFFFFF.
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