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       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


       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

       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 boundary.

       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

       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 system 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