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Raven PCI Host Bridge & Multi-Processor Interrupt Controller Chip
2
Each map decoder also includes a programmable 16-bit address offset. The
offset is added to the 16 most significant bits of the MPC address, and the
result is used as the PCI address. This offset allows PCI devices to reside
at any PCI address, independent of the MPC address map. An example of
this is shown below.
Figure 2-3. MPC to PCI Address Translation
Care should be taken to assure that all programmable decoders decode
unique address ranges since overlapping address ranges will lead to
undefined operation.
MPC Slave
The MPC slave provides the interface between the MPC bus and the Raven
FIFOs. The MPC slave is responsible for tracking and maintaining
coherency to the 60x processor bus protocol.
The MPC slave divides MPC command types into three categories:
address only, write, and read. If a command type is an address only and the
address presented at the time of the command is a valid Raven address, the
MPC Bus Address
8 0 8 0 1 2 3 4
31
16
15
0
MSOFFx Register
9 0 0 0
15
0
+
PCI Bus Address
1 0 8 0 1 2 3 4
0
15
16
31
=