Pci Arbitration - Motorola MVME1603 Installation And Use Manual

PCI Arbitration

There are 6 potential PCI bus masters on the MVME1603/MVME1604
single-board computer:
The IBC supplies the PCI arbitration support for these six devices. The
IBC supports flexible arbitration modes of fixed priority, rotating priority,
and mixed priority.
The IBC registers that control the arbitration mode are the PCI Arbiter
Priority Control (PAPC) Register and the PCI Arbiter Priority Control
Extension (ARBPRIX) Register. The PAPC register and the ARBPRIX
register default to 04 (hex) and 00 (hex) respectively. This default
configuration puts the CPU (MPC105) at the highest priority level. Refer
to the S82378ZB Reference Manual for programming information.
The following figure shows the arbitration configuration diagram of the
IBC. Additional details on PCI arbitration can be found in the
Programmer's Reference Guide (part number V1600-1A/PG).
MPC105 (PCI/MPU bus bridge and memory controller)
IBC (PCI/ISA bus bridge controller)
DECchip 21040 Ethernet controller
53C825 (or 53C810) SCSI controller
VME2PCI ASIC (PCI/VMEchip2 interface ASIC
PMC (PCI mezzanine card) slot
Operating Instructions
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