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Diffstat (limited to 'Documentation/hwmon/coretemp')
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diff --git a/Documentation/hwmon/coretemp b/Documentation/hwmon/coretemp new file mode 100644 index 000000000000..870cda9416e9 --- /dev/null +++ b/Documentation/hwmon/coretemp @@ -0,0 +1,36 @@ +Kernel driver coretemp +====================== + +Supported chips: + * All Intel Core family + Prefix: 'coretemp' + CPUID: family 0x6, models 0xe, 0xf + Datasheet: Intel 64 and IA-32 Architectures Software Developer's Manual + Volume 3A: System Programming Guide + +Author: Rudolf Marek + +Description +----------- + +This driver permits reading temperature sensor embedded inside Intel Core CPU. +Temperature is measured in degrees Celsius and measurement resolution is +1 degree C. Valid temperatures are from 0 to TjMax degrees C, because +the actual value of temperature register is in fact a delta from TjMax. + +Temperature known as TjMax is the maximum junction temperature of processor. +Intel defines this temperature as 85C or 100C. At this temperature, protection +mechanism will perform actions to forcibly cool down the processor. Alarm +may be raised, if the temperature grows enough (more than TjMax) to trigger +the Out-Of-Spec bit. Following table summarizes the exported sysfs files: + +temp1_input - Core temperature (in millidegrees Celsius). +temp1_crit - Maximum junction temperature (in millidegrees Celsius). +temp1_crit_alarm - Set when Out-of-spec bit is set, never clears. + Correct CPU operation is no longer guaranteed. +temp1_label - Contains string "Core X", where X is processor + number. + +The TjMax temperature is set to 85 degrees C if undocumented model specific +register (UMSR) 0xee has bit 30 set. If not the TjMax is 100 degrees C as +(sometimes) documented in processor datasheet. |