VME-bus Adapter Requests

VME-bus Adapter Requests

The VME-bus adapter provides four levels of bus request, 0-3, (3 has the highest priority) for DMA arbitration. Do not confuse these bus request levels with the interrupt priorities described below. Bus requests prioritize the use of the physical lines representing the bus and are normally set by means of jumpers on the interface board. The IRIS-4D/20, 4D/25, 4D/30, and 4D/35 support only Bus Request level 3 and Bus Grant level 3.