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Documentation for the coretemp driver. Signed-off-by: Rudolf Marek <r.marek@assembler.cz> Signed-off-by: Jean Delvare <khali@linux-fr.org>
37 lines
1.5 KiB
Plaintext
37 lines
1.5 KiB
Plaintext
Kernel driver coretemp
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======================
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Supported chips:
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* All Intel Core family
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Prefix: 'coretemp'
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CPUID: family 0x6, models 0xe, 0xf
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Datasheet: Intel 64 and IA-32 Architectures Software Developer's Manual
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Volume 3A: System Programming Guide
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Author: Rudolf Marek
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Description
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-----------
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This driver permits reading temperature sensor embedded inside Intel Core CPU.
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Temperature is measured in degrees Celsius and measurement resolution is
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1 degree C. Valid temperatures are from 0 to TjMax degrees C, because
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the actual value of temperature register is in fact a delta from TjMax.
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Temperature known as TjMax is the maximum junction temperature of processor.
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Intel defines this temperature as 85C or 100C. At this temperature, protection
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mechanism will perform actions to forcibly cool down the processor. Alarm
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may be raised, if the temperature grows enough (more than TjMax) to trigger
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the Out-Of-Spec bit. Following table summarizes the exported sysfs files:
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temp1_input - Core temperature (in millidegrees Celsius).
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temp1_crit - Maximum junction temperature (in millidegrees Celsius).
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temp1_crit_alarm - Set when Out-of-spec bit is set, never clears.
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Correct CPU operation is no longer guaranteed.
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temp1_label - Contains string "Core X", where X is processor
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number.
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The TjMax temperature is set to 85 degrees C if undocumented model specific
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register (UMSR) 0xee has bit 30 set. If not the TjMax is 100 degrees C as
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(sometimes) documented in processor datasheet.
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