In an information processing system which has plurality of modules
including a processor, a main memory and a plurality of I/O devices, a
data transfer switch for performing data transfer operations between the
processor, main memory and I/O devices comprises a request bus which has
a request bus arbiter for receiving read and write requests from each one
of the plurality of modules. A processor memory bus is configured to
receive address and data information from a predetermined number of
modules, including the processor. The processor memory bus has a data bus
arbiter for receiving data read and write requests from each one of the
predetermined number of modules which are coupled to the processor memory
bus.An internal memory bus is configured to receive address and data
information from a predetermined number of modules, including the memory
and the I/O devices. The internal memory bus has a data bus arbiter for
receiving data read and write requests from each one of the predetermined
number of modules coupled to the internal memory bus. A transceiver
system is coupled to the processor memory bus and the internal memory bus
for transferring data between the processor memory bus and the internal
memory bus.