66 lines
2.5 KiB
Text
66 lines
2.5 KiB
Text
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Kernel driver lm75
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==================
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Supported chips:
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* National Semiconductor LM75
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Prefix: 'lm75'
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Addresses scanned: I2C 0x48 - 0x4f
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Datasheet: Publicly available at the National Semiconductor website
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http://www.national.com/
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* Dallas Semiconductor DS75
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Prefix: 'lm75'
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Addresses scanned: I2C 0x48 - 0x4f
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Datasheet: Publicly available at the Dallas Semiconductor website
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http://www.maxim-ic.com/
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* Dallas Semiconductor DS1775
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Prefix: 'lm75'
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Addresses scanned: I2C 0x48 - 0x4f
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Datasheet: Publicly available at the Dallas Semiconductor website
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http://www.maxim-ic.com/
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* Maxim MAX6625, MAX6626
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Prefix: 'lm75'
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Addresses scanned: I2C 0x48 - 0x4b
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Datasheet: Publicly available at the Maxim website
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http://www.maxim-ic.com/
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* Microchip (TelCom) TCN75
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Prefix: 'lm75'
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Addresses scanned: I2C 0x48 - 0x4f
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Datasheet: Publicly available at the Microchip website
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http://www.microchip.com/
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Author: Frodo Looijaard <frodol@dds.nl>
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Description
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-----------
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The LM75 implements one temperature sensor. Limits can be set through the
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Overtemperature Shutdown register and Hysteresis register. Each value can be
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set and read to half-degree accuracy.
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An alarm is issued (usually to a connected LM78) when the temperature
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gets higher then the Overtemperature Shutdown value; it stays on until
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the temperature falls below the Hysteresis value.
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All temperatures are in degrees Celsius, and are guaranteed within a
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range of -55 to +125 degrees.
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The LM75 only updates its values each 1.5 seconds; reading it more often
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will do no harm, but will return 'old' values.
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The LM75 is usually used in combination with LM78-like chips, to measure
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the temperature of the processor(s).
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The DS75, DS1775, MAX6625, and MAX6626 are supported as well.
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They are not distinguished from an LM75. While most of these chips
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have three additional bits of accuracy (12 vs. 9 for the LM75),
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the additional bits are not supported. Not only that, but these chips will
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not be detected if not in 9-bit precision mode (use the force parameter if
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needed).
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The TCN75 is supported as well, and is not distinguished from an LM75.
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The LM75 is essentially an industry standard; there may be other
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LM75 clones not listed here, with or without various enhancements,
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that are supported.
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The LM77 is not supported, contrary to what we pretended for a long time.
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Both chips are simply not compatible, value encoding differs.
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