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1Kernel driver coretemp
2======================
3
4Supported chips:
5 * All Intel Core family
6 Prefix: 'coretemp'
7 CPUID: family 0x6, models 0xe, 0xf
8 Datasheet: Intel 64 and IA-32 Architectures Software Developer's Manual
9 Volume 3A: System Programming Guide
10
11Author: Rudolf Marek
12
13Description
14-----------
15
16This driver permits reading temperature sensor embedded inside Intel Core CPU.
17Temperature is measured in degrees Celsius and measurement resolution is
181 degree C. Valid temperatures are from 0 to TjMax degrees C, because
19the actual value of temperature register is in fact a delta from TjMax.
20
21Temperature known as TjMax is the maximum junction temperature of processor.
22Intel defines this temperature as 85C or 100C. At this temperature, protection
23mechanism will perform actions to forcibly cool down the processor. Alarm
24may be raised, if the temperature grows enough (more than TjMax) to trigger
25the Out-Of-Spec bit. Following table summarizes the exported sysfs files:
26
27temp1_input - Core temperature (in millidegrees Celsius).
28temp1_crit - Maximum junction temperature (in millidegrees Celsius).
29temp1_crit_alarm - Set when Out-of-spec bit is set, never clears.
30 Correct CPU operation is no longer guaranteed.
31temp1_label - Contains string "Core X", where X is processor
32 number.
33
34The TjMax temperature is set to 85 degrees C if undocumented model specific
35register (UMSR) 0xee has bit 30 set. If not the TjMax is 100 degrees C as
36(sometimes) documented in processor datasheet.