Preparing to Install VME Options1-10 014–001867The card cage assembly provides standard P1 and P2 VMEbus signals to each set ofboard connectors on the backplane. Appendix A lists the connector signals on thebackplane; for more information about the VMEbus specification, refer to themanual The VMEbus Specification. The assembly can also provide specialproprietary bus signals, described in the programming system I/O documentation foryour computer.Board SlotsFigure 1–4 shows the card cage’s location and board slot arrangement for acomputer that supports two VME option boards. Note that on the particular AViiONsystem depicted, the system board occupies the first slot on the VMEbus, and residesoutside the VME card cage (other AViiON systems may be configured differently).Slot 2VMEbackplaneSystem board(Slot 1)Slot 3System boardconnectors tobackplaneAViiON computer — rear view VME card cage(exposed)Figure 1–4 Board Slots in the VME Card CageArbiterThat part of the host logic that arbitrates requests and controls traffic on theVMEbus is referred to as the arbiter. On some AViiON systems, the arbiter is part ofthe system board which occupies the first place, slot 1, on a VMEbus even thoughphysically the board does not reside within the VME card cage. On other AViiONsystems, the arbiter may be part of or attaches to the input/output controller (IOC)that resides either in slot 1 or some other location within the system logic area.
