linux/Documentation/isdn/README.hfc-pci

The driver for the HFC-PCI and HFC-PCI-A chips from CCD may be used
for many OEM cards using this chips.
Additionally the driver has a special feature which makes it possible
to read the echo-channel of the isdn bus. So all frames in both directions
may be logged.
When the echo logging feature is used the number of available B-channels
for a HFC-PCI card is reduced to 1. Of course this is only relevant to
the card, not to the isdn line.
To activate the echo mode the following ioctls must be entered:

hisaxctrl <driver/cardname> 10 1

This reduces the available channels to 1. There must not be open connections
through this card when entering the command.
And then:

hisaxctrl <driver/cardname> 12 1

This enables the echo mode. If Hex logging is activated the isdnctrlx 
devices show a output with a line beginning of HEX: for the providers
exchange and ECHO: for isdn devices sending to the provider.

If more than one HFC-PCI cards are installed, a specific card may be selected
at the hisax module load command line. Supply the load command with the desired
IO-address of the desired card. 
Example:
There tree cards installed in your machine at IO-base addresses 0xd000, 0xd400 
and 0xdc00
If you want to use the card at 0xd400 standalone you should supply the insmod
or depmod with type=35 io=0xd400.
If you want to use all three cards, but the order needs to be at 0xdc00,0xd400,
0xd000 you may give the parameters type=35,35,35 io=0xdc00,0xd400,0xd00 
Then the desired card will be the initialised in the desired order.
If the io parameter is used the io addresses of all used cards should be 
supplied else the parameter is assumed 0 and a auto search for a free card is
invoked which may not give the wanted result. 

Comments and reports to werner@isdn4linux.de or werner@isdn-development.de