i2cset

I2CSET(8)                                                            I2CSET(8)

NAME

       i2cset - set I2C registers

SYNOPSIS

       i2cset [-y] i2cbus chip-address data-address value [mode] [mask]
       i2cset -V

DESCRIPTION

       i2cset  is  a small helper program to set registers visible through the
       I2C bus.

OPTIONS

       -V     Display the version and exit.

       -y     Disable interactive mode. By default, i2cset  will  wait  for  a
              confirmation from the user before messing with the I2C bus. When
              this flag is used, it will perform the operation directly.  This
              is mainly meant to be used in scripts.

       There  are four required options to i2cset. i2cbus indicates the number
       of the I2C bus to be scanned.  This number should correspond to one  of
       the  busses  listed by i2cdetect -l. chip-address specifies the address
       of the chip on that bus, and is  an  integer  between  0x00  and  0x7F.
       data-address  specifies the address on that chip to write to, and is an
       integer between 0x00 and 0xFF. value is the  value  to  write  to  that
       location on the chip.

       The  mode parameter, if specified, is one of the letters b or w, corre-
       sponding to a write size of a single byte or  a  16-bit  word,  respec-
       tively. If the mode parameter is omitted, i2cset defaults to byte mode.
       The value provided must be within range for  the  specified  data  type
       (0x00-0xFF for bytes, 0x0000-0xFFFF for words).

       The mask parameter, if specified, describes which bits of value will be
       actually written to data-address. Bits set to 1 in the mask  are  taken
       from value, while bits set to 0 will be read from data-address and thus
       preserved by the operation.

WARNING

       i2cset can be extremely dangerous if used improperly.  It  can  confuse
       your I2C bus, cause data loss, or have more serious side effects. Writ-
       ing to a serial EEPROM on a memory DIMM (chip  addresses  between  0x50
       and  0x57) may DESTROY your memory, leaving your system unbootable!  Be
       extremely careful using this program.

CONFORMING TO

       lm_sensors-2.x

SEE ALSO

       i2cdump(8), isaset(8)

AUTHOR

       Frodo  Looijaard,  Mark  D.  Studebaker,  and  the   lm_sensors   group
       http://www.lm-sensors.nu/  This  manual  page was originally written by
       David Z Maze <dmaze@debian.org> for the Debian GNU/Linux system. It was
       then  reviewed by the lm_sensors team and is now part of the lm_sensors
       source distribution.



                                  August 2004                        I2CSET(8)