FIC M296 - Manual (Page 79)

Software Functional Overview
resetting cooling temperatures. For example,
1. When the heat increases to the temperature designated by _ACx, the OS
will turn on the associated active cooling device and the hardware will
reset the ACx value to a lower temperature.
2. The hardware will then run the Notify command and the OS will
reevaluate the new temperatures. Because of the lower _ACx value now,
the fan will be turned off at a lower temperature than when turned on
.
3. When the temperature hits the lower _ACx value, the OS will turn off the
fan and reevaluate the control methods when notified.
3.6.3 Hardware Thermal Events
An ACPI-compatible OS expects the hardware to generate a thermal event notification
through the use of the SCI. When the OS receives the SCI event, it will run the _TMP control
method to evaluate the current temperature. Then the OS will compare the value to the
cooling policy temperatures. If the temperature has crossed over one of the three policy
thresholds, then the OS will actively or passively cool (or stop cooling) the system, or
shutdown the system entirely.
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_AC1
_PSV
_CRT
Method
SCI Event
This is an SCI and you
can define how ever
many as necessary
_AC0
Both the number of SCI events to be implemented and the granularity of the temperature
separation between each SCI event is OEM-specific. However, it is important to note that
since the OS can use heuristic knowledge to help cool the system, the more events the OS
receives the better understanding it will have of the system thermal characteristic.
3.6.4 Active Cooling Strength
The Active cooling methods (_Acx) in conjunction with active cooling lists (_ALx), allows an
OEM to use a device that offers varying degrees of cooling capability or multiple cooling
devices. The _ACx method designates the temperature at which the Active cooling is enabled
or disabled (depending upon the direction in which the temperature is changing). The _ALx
method evaluates to a list of devices that actively cool the zone. For example:
FIC M295 / M296 Service Manual
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