| Rudolf Marek | d58ee05 | 2007-05-08 17:22:02 +0200 | [diff] [blame] | 1 | Kernel driver coretemp |
| 2 | ====================== |
| 3 | |
| 4 | Supported chips: |
| 5 | * All Intel Core family |
| 6 | Prefix: 'coretemp' |
| Rudolf Marek | c940336 | 2007-10-07 13:42:09 +0200 | [diff] [blame] | 7 | CPUID: family 0x6, models 0xe, 0xf, 0x16 |
| Rudolf Marek | d58ee05 | 2007-05-08 17:22:02 +0200 | [diff] [blame] | 8 | Datasheet: Intel 64 and IA-32 Architectures Software Developer's Manual |
| 9 | Volume 3A: System Programming Guide |
| 10 | |
| 11 | Author: Rudolf Marek |
| 12 | |
| 13 | Description |
| 14 | ----------- |
| 15 | |
| 16 | This driver permits reading temperature sensor embedded inside Intel Core CPU. |
| 17 | Temperature is measured in degrees Celsius and measurement resolution is |
| 18 | 1 degree C. Valid temperatures are from 0 to TjMax degrees C, because |
| 19 | the actual value of temperature register is in fact a delta from TjMax. |
| 20 | |
| 21 | Temperature known as TjMax is the maximum junction temperature of processor. |
| 22 | Intel defines this temperature as 85C or 100C. At this temperature, protection |
| 23 | mechanism will perform actions to forcibly cool down the processor. Alarm |
| 24 | may be raised, if the temperature grows enough (more than TjMax) to trigger |
| 25 | the Out-Of-Spec bit. Following table summarizes the exported sysfs files: |
| 26 | |
| 27 | temp1_input - Core temperature (in millidegrees Celsius). |
| 28 | temp1_crit - Maximum junction temperature (in millidegrees Celsius). |
| 29 | temp1_crit_alarm - Set when Out-of-spec bit is set, never clears. |
| 30 | Correct CPU operation is no longer guaranteed. |
| 31 | temp1_label - Contains string "Core X", where X is processor |
| 32 | number. |
| 33 | |
| 34 | The TjMax temperature is set to 85 degrees C if undocumented model specific |
| 35 | register (UMSR) 0xee has bit 30 set. If not the TjMax is 100 degrees C as |
| 36 | (sometimes) documented in processor datasheet. |