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1 | Kernel driver lm95234 |
2 | ===================== | |
3 | ||
4 | Supported chips: | |
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5 | * National Semiconductor / Texas Instruments LM95233 |
6 | Addresses scanned: I2C 0x18, 0x2a, 0x2b | |
7 | Datasheet: Publicly available at the Texas Instruments website | |
8 | http://www.ti.com/product/lm95233 | |
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9 | * National Semiconductor / Texas Instruments LM95234 |
10 | Addresses scanned: I2C 0x18, 0x4d, 0x4e | |
11 | Datasheet: Publicly available at the Texas Instruments website | |
12 | http://www.ti.com/product/lm95234 | |
13 | ||
14 | ||
15 | Author: Guenter Roeck <linux@roeck-us.net> | |
16 | ||
17 | Description | |
18 | ----------- | |
19 | ||
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20 | LM95233 and LM95234 are 11-bit digital temperature sensors with a 2-wire |
21 | System Management Bus (SMBus) interface and TrueTherm technology | |
22 | that can very accurately monitor the temperature of two (LM95233) | |
23 | or four (LM95234) remote diodes as well as its own temperature. | |
24 | The remote diodes can be external devices such as microprocessors, | |
25 | graphics processors or diode-connected 2N3904s. The chip's TruTherm | |
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26 | beta compensation technology allows sensing of 90 nm or 65 nm process |
27 | thermal diodes accurately. | |
28 | ||
29 | All temperature values are given in millidegrees Celsius. Temperature | |
30 | is provided within a range of -127 to +255 degrees (+127.875 degrees for | |
31 | the internal sensor). Resolution depends on temperature input and range. | |
32 | ||
33 | Each sensor has its own maximum limit, but the hysteresis is common to all | |
34 | channels. The hysteresis is configurable with the tem1_max_hyst attribute and | |
35 | affects the hysteresis on all channels. The first two external sensors also | |
36 | have a critical limit. | |
37 | ||
38 | The lm95234 driver can change its update interval to a fixed set of values. | |
39 | It will round up to the next selectable interval. See the datasheet for exact | |
40 | values. Reading sensor values more often will do no harm, but will return | |
41 | 'old' values. |