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Guenter Roecke1eb4902013-03-10 16:54:19 -07001Kernel driver lm95234
2=====================
3
4Supported chips:
5 * National Semiconductor / Texas Instruments LM95234
6 Addresses scanned: I2C 0x18, 0x4d, 0x4e
7 Datasheet: Publicly available at the Texas Instruments website
8 http://www.ti.com/product/lm95234
9
10
11Author: Guenter Roeck <linux@roeck-us.net>
12
13Description
14-----------
15
16LM95234 is an 11-bit digital temperature sensor with a 2-wire System Management
17Bus (SMBus) interface and TrueTherm technology that can very accurately monitor
18the temperature of four remote diodes as well as its own temperature.
19The four remote diodes can be external devices such as microprocessors,
20graphics processors or diode-connected 2N3904s. The LM95234's TruTherm
21beta compensation technology allows sensing of 90 nm or 65 nm process
22thermal diodes accurately.
23
24All temperature values are given in millidegrees Celsius. Temperature
25is provided within a range of -127 to +255 degrees (+127.875 degrees for
26the internal sensor). Resolution depends on temperature input and range.
27
28Each sensor has its own maximum limit, but the hysteresis is common to all
29channels. The hysteresis is configurable with the tem1_max_hyst attribute and
30affects the hysteresis on all channels. The first two external sensors also
31have a critical limit.
32
33The lm95234 driver can change its update interval to a fixed set of values.
34It will round up to the next selectable interval. See the datasheet for exact
35values. Reading sensor values more often will do no harm, but will return
36'old' values.