lmtemp(4) - NetBSD Manual Pages

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LMTEMP(4)               NetBSD Kernel Interfaces Manual              LMTEMP(4)


NAME

     lmtemp -- National Semiconductor LM75, LM77 and compatible hardware moni-
     tors


SYNOPSIS

     lmtemp0 at iic? addr 0x48 flags 0x0000


DESCRIPTION

     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


HARDWARE

     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.


SEE ALSO

     envsys(4), envstat(8)


HISTORY

     The lmtemp device appeared in NetBSD 4.0.


BUGS

     Interrupt support is unimplemented.

NetBSD 9.2                      January 1, 2016                     NetBSD 9.2