Advanced Configuration and Power Interface Specification

Processor Configuration and Control
will use the processor control register from the _PTC object and the P_LVLx registers from the
P_BLK.
Example
This is an example usage of the _PTC object in a Processor object list:
Processor (
\_SB.CPU0,
// Processor Name
1, // ACPI Processor number
0x120, // PBlk system IO address
6 ) // PBlkLen
{ // Object List
Name(_PTC, Package () // Processor Throttling Control object
{
ResourceTemplate(){Register(FFixedHW, 0, 0, 0)}, // Throttling_CTRL
ResourceTemplate(){Register(FFixedHW, 0, 0, 0)} // Throttling_STATUS
}) // End of _PTC object
} // End of Object List
Example
This is an example usage of the _PTC object using the values defined in ACPI 1.0. This is an
illustrative example to demonstrate the mechanism with well-known values.
Processor (
\_SB.CPU0,
// Processor Name
1, // ACPI Processor number
0x120, // PBLK system IO address
6 ) // PBLK Len
{ // Object List
Name(_PTC, Package () // Processor Throttling Control object –
// 32 bit wide IO space-based register at the address
{
ResourceTemplate(){Register(SystemIO, 32, 0, 0x120)}, // Throttling_CTRL
ResourceTemplate(){Register(SystemIO, 32, 0, 0x120)} // Throttling_STATUS
}) // End of _PTC object
} // End of Object List
8.4.5.2 _TSS (Throttling Supported States)
This optional object indicates to OSPM the number of supported processor throttling states that a
platform supports. This object evaluates to a packaged list of information about available throttling
states including percentage of maximum internal CPU core frequency, maximum power dissipation,
control register values needed to transition between throttling states, and status register values that
allow OSPM to verify throttling state transition status after any OS-initiated transition change
request. The list is sorted in descending order by power dissipation. As a result, the zeroth entry
describes the highest performance throttling state (no throttling applied) and the ‘nth’ entry describes
the lowest performance throttling state (maximum throttling applied).
When providing the _TSS, the platform must supply a _TSS entry whose Percent field value is 100.
This provides a means for OSPM to disable throttling and achieve maximum performance.
Arguments:
None
Version 6.0 463