Advanced Configuration and Power Interface Specification
Hewlett-Packard/Intel/Microsoft/Phoenix/Toshiba xiii
11.4.10 _RTV (Relative Temperature Values) ........................................................... 538
11.4.11 _SCP (Set Cooling Policy) ............................................................................ 538
11.4.12 _TC1 (Thermal Constant 1) .......................................................................... 541
11.4.13 _TC2 (Thermal Constant 2) .......................................................................... 541
11.4.14 _TMP (Temperature)..................................................................................... 542
11.4.15 _TPT (Trip Point Temperature) ..................................................................... 542
11.4.16 _TRT (Thermal Relationship Table).............................................................. 542
11.4.17 _TSP (Thermal Sampling Period) ................................................................. 543
11.4.18 _TST (Temperature Sensor Threshold) ........................................................ 543
11.4.19 _TZD (Thermal Zone Devices)...................................................................... 544
11.4.20 _TZM (Thermal Zone Member)..................................................................... 544
11.4.21 _TZP (Thermal Zone Polling)........................................................................ 544
11.5 Native OS Device Driver Thermal Interfaces .............................................................. 545
11.6 Thermal Zone Interface Requirements ....................................................................... 546
11.7 Thermal Zone Examples............................................................................................. 546
11.7.1 Example: The Basic Thermal Zone................................................................. 546
11.7.2 Example: Multiple-Speed Fans ....................................................................... 548
11.7.3 Example: Thermal Zone with Multiple Devices ............................................... 550
12
ACPI Embedded Controller Interface Specification ................................ 557
12.1 Embedded Controller Interface Description ................................................................ 557
12.2 Embedded Controller Register Descriptions............................................................... 561
12.2.1 Embedded Controller Status, EC_SC (R) ....................................................... 561
12.2.2 Embedded Controller Command, EC_SC (W)................................................ 562
12.2.3 Embedded Controller Data, EC_DATA (R/W)................................................. 562
12.3 Embedded Controller Command Set .......................................................................... 562
12.3.1 Read Embedded Controller, RD_EC (0x80) ................................................... 563
12.3.2 Write Embedded Controller, WR_EC (0x81).................................................. 563
12.3.3 Burst Enable Embedded Controller, BE_EC (0x82)........................................ 563
12.3.4 Burst Disable Embedded Controller, BD_EC (0x83)....................................... 564
12.3.5 Query Embedded Controller, QR_EC (0x84).................................................. 564
12.4 SMBus Host Controller Notification Header (Optional), OS_SMB_EVT ..................... 564
12.5 Embedded Controller Firmware .................................................................................. 564
12.6 Interrupt Model............................................................................................................565
12.6.1 Event Interrupt Model...................................................................................... 565
12.6.2 Command Interrupt Model .............................................................................. 566
12.7 Embedded Controller Interfacing Algorithms .............................................................. 566
12.8 Embedded Controller Description Information ............................................................ 567
12.9 SMBus Host Controller Interface via Embedded Controller....................................... 567
12.9.1 Register Description........................................................................................ 568
12.9.2 Protocol Description ........................................................................................ 572
12.10 SMBus Devices......................................................................................................... 577
12.10.1 SMBus Device Access Restrictions .............................................................. 578
12.10.2 SMBus Device Command Access Restriction .............................................. 578
12.11 Defining an Embedded Controller Device in ACPI Namespace ............................... 578
12.11.1 Example: EC Definition ASL Code ............................................................... 579