Programming Details

5

Introduction

This chapter discusses 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 MVME2300 series are as follows:

Table 5-1. PCI Arbitration Assignments

Pci Bus Request

PCI Master(s)

 

 

PIB (internal)

PIB

 

 

CPU

Raven ASIC

 

 

Request 0

PMC Slot 2

 

 

Request 1

PMC Slot 1

 

 

Request 2

PCIX Slot

 

 

Request 3

Ethernet

 

 

Request 4

Universe ASIC (VMEbus)

 

 

Upon power-up, the PIB defaults to a “round-robin” arbitration mode. The relative priority of each request/grant pair can be customized via PCI Priority Control Register 1. Refer to the W83C553 Data Book for additional details, in Appendix A, Related Documentation.

5-1

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Motorola MVME2300 Series manual PCI Arbitration Assignments, Pci Bus Request PCI Masters, Pib, Cpu