root/lm-sensors/trunk/doc/chips/lm75 @ 785

Revision 785, 3.4 KB (checked in by mds, 14 years ago)

(mds) Claim support for Dallas Semi DS75 and DS1775, which are

LM75 clones. No separate detection and no support of
extended precision.

  • Property svn:eol-style set to native
  • Property svn:keywords set to Author Date Id Revision
Line 
1Kernel driver `lm75.o'
2=====================
3
4Status: Complete and well-tested
5
6Supported chips:
7  * National Semiconductor LM75
8    Prefix: `lm75'
9    Addresses scanned: I2C 0x48 - 0x4f (inclusive)
10    Datasheet: Publicly available at the National Semiconductor website
11               http://www.national.com
12  * National Semiconductor LM77
13    Prefix: `lm75'
14    Addresses scanned: I2C 0x48 - 0x4b (inclusive)
15    Datasheet: Publicly available at the National Semiconductor website
16               http://www.national.com
17  * Dallas Semiconductor DS75
18    Prefix: `lm75'
19    Addresses scanned: I2C 0x48 - 0x4f (inclusive)
20    Datasheet: Publicly available at the Dallas Semiconductor website
21               http://www.dalsemi.com
22  * Dallas Semiconductor DS1775
23    Prefix: `lm75'
24    Addresses scanned: I2C 0x48 - 0x4f (inclusive)
25    Datasheet: Publicly available at the Dallas Semiconductor website
26               http://www.dalsemi.com
27
28Author: Frodo Looijaard <frodol@dds.nl>
29
30
31Module Parameters
32-----------------
33
34* force: short array (min = 1, max = 48)
35  List of adapter,address pairs to boldly assume to be present
36* force_lm75: short array (min = 1, max = 48)
37  List of adapter,address pairs which are unquestionably assumed to contain
38  a `lm75' chip
39* ignore: short array (min = 1, max = 48)
40  List of adapter,address pairs not to scan
41* ignore_range: short array (min = 1, max = 48)
42  List of adapter,start-addr,end-addr triples not to scan
43* probe: short array (min = 1, max = 48)
44  List of adapter,address pairs to scan additionally
45* probe_range: short array (min = 1, max = 48)
46  List of adapter,start-addr,end-addr triples to scan additionally
47
48
49Description
50-----------
51
52The LM75 implements one temperature sensor. Limits can be set through the
53Overtemperature Shutdown register and Hysteresis register. Each value can be
54set and read to half-degree accuracy.
55An alarm is issued (usually to a connected LM78) when the temperature
56gets higher then the Overtemperature Shutdown value; it stays on until
57the temperature falls below the Hysteresis value.
58All temperatures are in degrees Celcius, and are guaranteed within a
59range of -55 to +125 degrees.
60
61The LM75 only updates its values each 1.5 seconds; reading it more often
62will do no harm, but will return 'old' values.
63
64The LM75 is usually used in combination with LM78-like chips, to measure
65the temperature of the processor(s).
66
67The LM77 is supported as well. It is not distinguished from an LM75
68and the two additional registers in the LM77 are not supported.
69The prefix in the /proc directory is still 'lm75'.
70
71The DS75 and DS1775 are supported as well.
72They are not distinguished from an LM75. While these chips
73have three additional bits of accuracy (12 vs. 9 for the LM75),
74the additional bits are not supported.
75The prefix in the /proc directory is still 'lm75'.
76
77
78Chip Features
79-------------
80
81Chip `lm75'
82          LABEL     LABEL CLASS   COMPUTE CLASS ACCESS MAGNITUDE
83           temp            NONE            NONE      R     1
84      temp_hyst            temp            temp      RW    1
85      temp_over            temp            temp      RW    1
86
87          LABEL                           FEATURE SYMBOL     SYSCTL FILE:OFFSET
88           temp                        SENSORS_LM75_TEMP            temp:3
89      temp_hyst                   SENSORS_LM75_TEMP_HYST            temp:2
90      temp_over                   SENSORS_LM75_TEMP_OVER            temp:1
91
92
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