The specification discloses a method and related system that allows
hardware devices to participate in the coherency domain of a computer
system. More particularly, hardware devices such as network interface
cards, audio cards, input/output cards, and the like, are allowed to
participate on at least a limited basis in the coherency domain by having
cache memory that duplicates a FIFO buffer in main memory used to exchange
information between software and the hardware. To exchange information,
software writes to the FIFO buffer which invalidates the data in the
cache-type memory of the hardware device, and the invalidation message
acts to notify the hardware device of the availability of information in
the FIFO buffer.
