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Functional Description
For detailed programming information, refer to the
PCI-ISA Bridge (PIB) Controller
The MVME240x uses a Winbond W83C553 PCI/ISA Bridge (PIB) Controller to supply the interface between the PCI local bus and the ISA system I/O bus (diagrammed in Figure
The PIB controller provides the following functions:
❏PCI bus arbitration for:
–ISA (Industry Standard Architecture) bus DMA (not functional on MVME240x)
–The PHB (PCI Host Bridge) MPU/local bus interface function, implemented by the Hawk ASIC
–All
–The PMC slot
❏ISA bus arbitration for DMA devices
❏ISA interrupt mapping for four PCI interrupts
❏Interrupt controller functionality to support 14 ISA interrupts
❏Edge/level control for ISA interrupts
❏Seven independently programmable DMA channels
❏One
❏Three interval counters/timers
Accesses to the configuration space for the PIB controller are performed by way of the CONADD and CONDAT (Configuration Address and Data) registers in the PHB. The registers are located at offsets $CF8 and $CFC, respectively, from the PCI I/O base address.
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