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Rudolf Marekd58ee052007-05-08 17:22:02 +02001Kernel driver coretemp
2======================
3
4Supported chips:
5 * All Intel Core family
6 Prefix: 'coretemp'
Rudolf Marekeccfed42009-09-23 22:59:42 +02007 CPUID: family 0x6, models 0xe (Pentium M DC), 0xf (Core 2 DC 65nm),
8 0x16 (Core 2 SC 65nm), 0x17 (Penryn 45nm),
Huaxu Wanfa08acd2009-09-23 22:59:43 +02009 0x1a (Nehalem), 0x1c (Atom), 0x1e (Lynnfield)
Rudolf Marekd58ee052007-05-08 17:22:02 +020010 Datasheet: Intel 64 and IA-32 Architectures Software Developer's Manual
11 Volume 3A: System Programming Guide
Rudolf Marekae770152008-01-18 00:50:04 +010012 http://softwarecommunity.intel.com/Wiki/Mobility/720.htm
Rudolf Marekd58ee052007-05-08 17:22:02 +020013
14Author: Rudolf Marek
15
16Description
17-----------
18
19This driver permits reading temperature sensor embedded inside Intel Core CPU.
20Temperature is measured in degrees Celsius and measurement resolution is
211 degree C. Valid temperatures are from 0 to TjMax degrees C, because
22the actual value of temperature register is in fact a delta from TjMax.
23
24Temperature known as TjMax is the maximum junction temperature of processor.
25Intel defines this temperature as 85C or 100C. At this temperature, protection
26mechanism will perform actions to forcibly cool down the processor. Alarm
27may be raised, if the temperature grows enough (more than TjMax) to trigger
28the Out-Of-Spec bit. Following table summarizes the exported sysfs files:
29
30temp1_input - Core temperature (in millidegrees Celsius).
Rudolf Marek6369a2882008-01-18 00:42:54 +010031temp1_max - All cooling devices should be turned on (on Core2).
32temp1_crit - Maximum junction temperature (in millidegrees Celsius).
Rudolf Marekd58ee052007-05-08 17:22:02 +020033temp1_crit_alarm - Set when Out-of-spec bit is set, never clears.
34 Correct CPU operation is no longer guaranteed.
35temp1_label - Contains string "Core X", where X is processor
36 number.
37
38The TjMax temperature is set to 85 degrees C if undocumented model specific
39register (UMSR) 0xee has bit 30 set. If not the TjMax is 100 degrees C as
40(sometimes) documented in processor datasheet.