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ISADUMP(8)                                                          ISADUMP(8)

       isadump - examine ISA registers

       isadump [-y] [-k V1,V2...]  addrreg datareg [bank [bankreg]] #for I2C-like access
       isadump [-y] -f address [range [bank [bankreg]]] #for flat address space

       isadump is a small helper program to examine registers visible through the ISA bus. It is intended to probe any
       chip that lives on the ISA bus working with an address register and a data register (I2C-like access) or a flat
       range (of up to 256 bytes).

       -f     Enable flat address space mode.

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

       -k V1,V2...
              Specify  a  comma-separated  list  of  bytes to send as the key sequence to enter the chip configuration
              mode. Most Super-I/O chips need this.  Known key sequences are: 0x87,0x01,0x55,0x55 for  ITE,  0x55  for
              SMSC, 0x87,0x87 for Winbond and VIA, none needed for National Semiconductor.

OPTIONS (I2C-like access mode)
       At  least two options must be provided to isadump. addrreg contains the ISA address of the address register for
       the chip to probe; datareg contains the address of the data  register.  Both  addresses  are  integers  between
       0x0000  and  0x3FFF.  Usually,  if the chip's base address is 0x0nn0, the address register is at 0x0nn5 and the
       data register is at 0x0nn6. The most common base address for hardware monitoring chips is 0x0290.

       For Super-I/O chips, address register is typically at 0x2E with data register at 0x2F.

       The bank and bankreg parameters are useful on the Winbond chips as well as on  Super-I/O  chips.   bank  is  an
       integer  between  0  and  31,  and bankreg is an integer between 0x00 and 0xFF (default value: 0x4E for Winbond
       chips, 0x07 for Super-I/O chips). The W83781D datasheet has more information on bank selection.

OPTIONS (flat address space mode)
       In flat mode, only one parameter is mandatory. address contains the ISA address of the chip to probe; it is  an
       integer  between 0x0000 and 0xFFFF.  If provided, range is how many bytes should be read (must be a multiple of
       16). If the range isn't provided, it defaults to 256 bytes and the address is forcibly aligned  on  a  256-byte

       The  bank  and bankreg parameters are useful on the National Semiconductor PC87365 and PC87366 Super-I/O chips.
       bank is an integer between 0 and 31, and bankreg is an integer between 0x00 and 0xFF (default value: 0x09; must
       fit in the specified range). See the PC87365 datasheet for more information on bank selection.

       If no bank is specified, no bank change operation is performed.

       If a bank is specified, the original value is restored before isadump exits.

       Dumping  Super-I/O  chips  is  typically  a two-step process. First, you will have to access the main Super-I/O
       address using a command like: isadump 0x2e 0x2f 0x09.  This will select logical device 9 (correct value  depend
       on  the  chip). At 0x60 you will find the logical device address word, for example "ec c0".  Then you can use a
       command like: isadump -f 0xecc0 16.  This will dump the logical device registers. The correct range depends  on
       the chip.

       Poking  around in ISA data space is extremely dangerous.  Running isadump with random parameters can cause sys-
       tem crashes, data loss, and worse!  Be extremely careful when using this program.

       i2cdump(8), isaset(8)

       Frodo Looijaard, Mark D. Studebaker, and the lm_sensors group (

       This manual page was originally written by David Z Maze <> for the Debian GNU/Linux system.  It
       was then reviewed and augmented by the lm_sensors team and is now part of the lm_sensors source distribution.

                                  August 2004                       ISADUMP(8)