The
ioat driver provides support for BOCA Research IOAT66 boards that multiplex together up to six EIA RS-232C (CCITT V.28) communications interfaces.
Each
ioat device is the master device for up to six
com devices. The kernel configuration specifies these
com devices as slave devices of the
ioat device, as shown in the synopsis. The slave ID given for each
com device determines which bit in the interrupt multiplexing register is tested to find interrupts for that device. The port specification for the
ioat device is used to compute the base addresses for the
com subdevices. The port for the interrupt multiplexing register is not programmable.