Updated: 2022/Sep/29

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LM(4)                        Device Drivers Manual                       LM(4)

NAME
     lm - National Semiconductor LM78, LM79 and compatible hardware monitors

SYNOPSIS
     lm0 at isa? port 0x280 flags 0x00
     lm1 at isa? port 0x290 flags 0x00
     lm2 at isa? port 0x310 flags 0x00
     lm3 at isa? port 0xa00 flags 0x00
     lm0 at pnpbios0 index ? flags 0x00
     lm0 at iic? addr 0x2e flags 0x00
     lm* at wbsio?

DESCRIPTION
     The lm driver provides support for the National Semiconductor LM series
     hardware monitors and register compatible chips to be used with the
     envsys(4) API.

     The original LM78 hardware monitor supports 11 sensors:

           Sensor    Units    Typical Use
           IN0       uV DC    Core voltage
           IN1       uV DC    unknown
           IN2       uV DC    +3.3V
           IN3       uV DC    +5V
           IN4       uV DC    +12V
           IN5       uV DC    -12V
           IN6       uV DC    -5V
           Temp      uK       Motherboard Temperature
           Fan0      RPM      Fan
           Fan1      RPM      Chassis Fan
           Fan2      RPM      Fan
     For other devices, sensors' names and numbers will be different.

     Due to hardware limitations, fresh sensor data is only available every 2
     seconds.

HARDWARE
     Chips supported by the lm driver include:

           National Semiconductor LM78, LM78-J, LM79, and LM81.

           Nuvoton NCT5104D, NCT6775F, NCT6776F, NCT6102D, NCT6104D, NCT6106D,
           NCT6779D and NCT679[12356789]D.

           Winbond W83627HF*, W83627THF*, W83627EHF*, W83627DHG*, W83637HF*,
           W83697HF*, W83781D, W83782D*, W83783S*, W83791D*, W83791SD, and
           W83792D.

           ASUS AS99127F.

     For most of the Winbond chips (identified with a * above), the flags
     configuration option can be specified to select the type of temperature
     sensor:

           flags    Sensor Type
           0        Thermistor diode (Power-On default)
           1        Pentium-II diode
           2        2N3904 Bipolar
           4        Thermistor diode

SEE ALSO
     envsys(4), wbsio(4), envstat(8)

HISTORY
     The lm device appeared in NetBSD 1.5.

CAVEATS
     Some vendors connect these chips to non-standard thermal diodes and
     resistors.  This will result in bogus sensor values.

BUGS
     Interrupt support is unimplemented.

     There are currently no known pnpbios IDs assigned to LM chips.

NetBSD 10.99                   December 15, 2022                  NetBSD 10.99