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author | David Woodhouse <dwmw2@shinybook.infradead.org> | 2005-07-13 15:25:59 +0100 |
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committer | David Woodhouse <dwmw2@shinybook.infradead.org> | 2005-07-13 15:25:59 +0100 |
commit | 30beab1491f0b96b2f23d3fb68af01fd921a16d8 (patch) | |
tree | c580bdc0846269fbb10feeda901ecec1a48ee2ef /Documentation/hwmon/lm75 | |
parent | 21af6c4f2aa5f63138871b4ddd77d7ebf2588c9d (diff) | |
parent | c32511e2718618f0b53479eb36e07439aa363a74 (diff) |
Merge with /shiny/git/linux-2.6/.git
Diffstat (limited to 'Documentation/hwmon/lm75')
-rw-r--r-- | Documentation/hwmon/lm75 | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/Documentation/hwmon/lm75 b/Documentation/hwmon/lm75 new file mode 100644 index 00000000000..8e6356fe05d --- /dev/null +++ b/Documentation/hwmon/lm75 @@ -0,0 +1,65 @@ +Kernel driver lm75 +================== + +Supported chips: + * National Semiconductor LM75 + Prefix: 'lm75' + Addresses scanned: I2C 0x48 - 0x4f + Datasheet: Publicly available at the National Semiconductor website + http://www.national.com/ + * Dallas Semiconductor DS75 + Prefix: 'lm75' + Addresses scanned: I2C 0x48 - 0x4f + Datasheet: Publicly available at the Dallas Semiconductor website + http://www.maxim-ic.com/ + * Dallas Semiconductor DS1775 + Prefix: 'lm75' + Addresses scanned: I2C 0x48 - 0x4f + Datasheet: Publicly available at the Dallas Semiconductor website + http://www.maxim-ic.com/ + * Maxim MAX6625, MAX6626 + Prefix: 'lm75' + Addresses scanned: I2C 0x48 - 0x4b + Datasheet: Publicly available at the Maxim website + http://www.maxim-ic.com/ + * Microchip (TelCom) TCN75 + Prefix: 'lm75' + Addresses scanned: I2C 0x48 - 0x4f + Datasheet: Publicly available at the Microchip website + http://www.microchip.com/ + +Author: Frodo Looijaard <frodol@dds.nl> + +Description +----------- + +The LM75 implements one temperature sensor. Limits can be set through the +Overtemperature Shutdown register and Hysteresis register. Each value can be +set and read to half-degree accuracy. +An alarm is issued (usually to a connected LM78) when the temperature +gets higher then the Overtemperature Shutdown value; it stays on until +the temperature falls below the Hysteresis value. +All temperatures are in degrees Celsius, and are guaranteed within a +range of -55 to +125 degrees. + +The LM75 only updates its values each 1.5 seconds; reading it more often +will do no harm, but will return 'old' values. + +The LM75 is usually used in combination with LM78-like chips, to measure +the temperature of the processor(s). + +The DS75, DS1775, MAX6625, and MAX6626 are supported as well. +They are not distinguished from an LM75. While most of these chips +have three additional bits of accuracy (12 vs. 9 for the LM75), +the additional bits are not supported. Not only that, but these chips will +not be detected if not in 9-bit precision mode (use the force parameter if +needed). + +The TCN75 is supported as well, and is not distinguished from an LM75. + +The LM75 is essentially an industry standard; there may be other +LM75 clones not listed here, with or without various enhancements, +that are supported. + +The LM77 is not supported, contrary to what we pretended for a long time. +Both chips are simply not compatible, value encoding differs. |