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Raven PCI Host Bridge & Multi-Processor Interrupt Controller Chip
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RavenMPIC Control Registers:
The RavenMPIC control registers are located within either PCI Memory
or PCI I/O space using traditional PCI defined base registers within the
predefined 64-byte header. Please see
for more information.
PCI Slave
The PCI slave provides the control logic needed to interface the PCI bus to
Raven’s FIFOs. The PCI slave can accept either 32-bit or 64-bit
transactions, however it can only accept 32-bit addressing. There is no
limit to the length of the transfer that the slave can handle. During posted
write cycles, the slave will continue to accept write data until the write post
FIFO is full. If the write post FIFO is full, the slave will hold off the master
with wait states until there is more room in the FIFO. The slave will not
initiate a disconnect. If the write transaction is compelled, the slave will
hold off the master with wait states while each beat of data is being
transferred. The slave will acknowledge the completion of the transfer
only after the data transfer has successfully completed on the MPC bus. If
a read transaction is being performed within an address space marked for
prefetching, the slave (in conjunction with the MPC master) will attempt
to read ahead far enough on the MPC bus to allow for an uninterrupted
burst transaction on the PCI bus. Read transactions within address spaces
marked for no prefetching will be acknowledged on the PCI bus only after
a single beat read has successfully completed on the MPC bus. Each read
on the MPC bus will only be started after the previous read has been
acknowledged on the PCI bus and there is an indication that the PCI master
wishes for more data to be transferred.
The following paragraphs identify some associations between the
operation of the PCI slave and the PCI 2.0 Local Bus Specification
requirements.