Commit | Line | Data |
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1 | Kernel driver lm95245 |
2 | ================== | |
3 | ||
4 | Supported chips: | |
162a8dfe GR |
5 | * TI LM95235 |
6 | Addresses scanned: I2C 0x18, 0x29, 0x4c | |
7 | Datasheet: Publicly available at the TI website | |
8 | http://www.ti.com/lit/ds/symlink/lm95235.pdf | |
9 | * TI / National Semiconductor LM95245 | |
fffd80cc | 10 | Addresses scanned: I2C 0x18, 0x19, 0x29, 0x4c, 0x4d |
162a8dfe GR |
11 | Datasheet: Publicly available at the TI website |
12 | http://www.ti.com/lit/ds/symlink/lm95245.pdf | |
fffd80cc AS |
13 | |
14 | ||
15 | Author: Alexander Stein <alexander.stein@systec-electronic.com> | |
16 | ||
17 | Description | |
18 | ----------- | |
19 | ||
162a8dfe | 20 | LM95235 and LM95245 are 11-bit digital temperature sensors with a 2-wire System |
fffd80cc AS |
21 | Management Bus (SMBus) interface and TruTherm technology that can monitor |
22 | the temperature of a remote diode as well as its own temperature. | |
162a8dfe | 23 | The chips can be used to very accurately monitor the temperature of |
fffd80cc AS |
24 | external devices such as microprocessors. |
25 | ||
26 | All temperature values are given in millidegrees Celsius. Local temperature | |
27 | is given within a range of -127 to +127.875 degrees. Remote temperatures are | |
28 | given within a range of -127 to +255 degrees. Resolution depends on | |
29 | temperature input and range. | |
30 | ||
a41a8927 GR |
31 | Each sensor has its own critical limit. Additionally, there is a relative |
32 | hysteresis value common to both critical limits. To make life easier to | |
33 | user-space applications, two absolute values are exported, one for each | |
34 | channel, but these values are of course linked. Only the local hysteresis | |
35 | can be set from user-space, and the same delta applies to the remote | |
36 | hysteresis. | |
fffd80cc AS |
37 | |
38 | The lm95245 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. |