LMTEMP(4) | Device Drivers Manual | LMTEMP(4) |
lmtemp
— National
Semiconductor LM75, LM77 and compatible hardware monitors
lmtemp0 at iic? addr 0x48 flags 0x0000
The lmtemp
driver provides support for the
National Semiconductor LM on iicbus series temperature sensors and register
compatible chips.
Each device is specified by the value of the address and flags.
Device | addr | flags |
LM75 |
0x48 - 0x4f | 0x0000 |
LM75A |
0x48 - 0x4f | 0x0000 |
DS75 |
0x48 - 0x4f | 0x0001 |
LM77 |
0x48 - 0x4b | 0x0002 |
Chips supported by the lmtemp
driver
include:
Device | Range | Resolution |
National
Semiconductor LM75 |
-55 – +125 | 0.5 degC |
Texas Instruments
LM75A |
-55 – +125 | 0.5 degC |
Dallas
Semiconductor DS75 |
-55 – +125 | 0.0625 degC |
National
Semiconductor LM77 |
-55 – +130 | 0.5 degC |
The LM75, LM75A, and DS75 have a programmable high temperature limit. When this is exceeded, the device asserts an over-temperature output.
The LM77 has programmable low and high temperature limits. Exceeding either of these causes the device to assert an interrupt output. It also has a programmable critical high temperature limit, and exceeding this causes the device to assert a separate critical alarm output.
The sensor and limit values are made available through the envstat(8) interface.
The lmtemp
device appeared in
NetBSD 4.0.
Interrupt support is unimplemented.
January 1, 2016 | NetBSD 10.99 |