National Semiconductor LM78/79/81
temperature, voltage, and fan sensor
lm0 at isa? port 0x290
lm1 at isa? port 0x280
lm2 at isa? port 0x310
lm* at iic?
lm* at wbsio?
lm driver provides support for the
National Semiconductor LM78/79/81 hardware monitors and register compatible
chips to be used with the sysctl(8) interface.
The original LM78 hardware monitor supports 11 sensors:
||uV DC||Core voltage|
For other devices, sensors' names and numbers will be different.
Chips supported by the
- ASUS AS99127F
- National Semiconductor LM78 and LM78-J
- National Semiconductor LM79
- National Semiconductor LM81
- Nuvoton NCT6775F, NCT6776F, NCT6779D, NCT6791D, NCT6792D, NCT6793D, NCT6795D
- Winbond W83627HF, W83627THF, W83637HF and W83697HF
- Winbond W83627DHG, W83627UHG and W83627EHF
- Winbond W83781D, W83782D and W83783S
- Winbond W83791D, W83791SD and W83792D
Some devices can attach to both
can only attach to either one or the other. If the
lm driver detects a device attaching to both
isa(4), it will
detach the device from iic(4).
iic(4), isa(4), wbsio(4), sensorsd(8), sysctl(8)
lm driver first appeared in
NetBSD 1.5; OpenBSD support
was added in OpenBSD 3.4.
lm driver was written by
Bill Squier and ported to OpenBSD
3.4 by Alexander Yurchenko
The driver was largely rewritten for OpenBSD 3.9 by
Some vendors connect these chips to non-standard thermal diodes and resistors. This will result in bogus sensor values.
Interrupt support is unimplemented.
There are currently no known pnpbios IDs assigned to LM chips.
This driver attaches to the Winbond W83791SD chip even though that chip does not have any sensors.