Table 5-1. Pci Arbitration Assignments; Introduction - Motorola MVME2600 Series Reference Manual

Introduction

This chapter contains details of several programming functions that are not
tied to any specific ASIC chip.
PCI Arbitration
PCI arbitration is performed by the PCI-to-ISA Bridge (PIB) which
supports six PCI external PCI masters. The PIB can also be a PCI master
for ISA DMA functions. The arbitration assignments on the
MVME2600/2700 series are as follows:

Table 5-1. PCI Arbitration Assignments

PCI BUS
REQUEST
PIB (internal)
CPU
Request 0
Request 1
Request 2
Request 3
Request 4
Upon power-up, the PIB defaults to a "round-robin" arbitration mode. The
relative priority of each request/grant pair can be customized via the PCI
Priority Control Register 1. Refer to the W83C553 Data Book for
additional details.
5Programming Details
PCI Master(s)
PIB
Secondary Ethernet
Secondary SCSI
Raven ASIC
PMC Slot 2 (PCIX)
PMC Slot 1
Ethernet
SCSI
Universe ASIC (VMEbus)
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