Advanced Configuration and Power Interface Specification

Advanced Configuration and Power Interface Specification
Device (RTC0) {
Name(_HID, EISAID("PNP0B01"))
Name (_FIX, Package(1) {
EISAID("PNP0B01") }
)
Name(_CRS, ResourceTemplate() {
IO(Decode16, 0x70, 0x70, 0x1, 0x2)
IO(Decode16, 0x72, 0x72, 0x1, 0x2)
}
OperationRegion(CMS1, SystemCMOS, 0, 0x100)
Field(CMS1, ByteAcc, NoLock, Preserve) {
AccessAs(ByteAcc, 0),
CM00, 8,
,256,
CM01, 8,
CM02, 16,
, 224,
CM03, 8,
, 184,
CENT, 8
}
9.15.3 Dallas Semiconductor-compatible RTC/CMOS Devices
(PNP0B02)
Dallas Semiconductor RTC/CMOS devices are compatible with the one in the PC/AT, but they
contain 256 bytes of non-volatile RAM or more. The first 64 bytes are accessed via the same
mechanism as the 64 bytes in the PC/AT. The upper bytes are accessed through an interface that is
only used on Dallas Semiconductor chips.
Any platform containing this device or one that is compatible with it may use the PNP ID PNP0B02.
This will allow an ACPI-compatible OS to recognize the RTC/CMOS device as using the Dallas
Semiconductor programming interface. Thus, the array of bytes that ASL can read and write with
this device is 256 bytes long.
Description of these devices is similar to the PIIX4 example above, and the CENTURY field of the
FADT may also contain values between 0 and 255.
9.16 User Presence Detection Device
The following section illustrates the operation and definition of the control method-based User
Presence Detection (UPD) device.
The user presence detection device can optionally support power management objects (e.g. _PS0,
_PS3) to allow the OS to manage the device’s power consumption.
The Plug and Play ID of an ACPI control method user presence detection device is ACPI000F.
536 April, 2015 Version 6.0