VME Bus in Silicon Graphics Systems

VME Bus in Silicon Graphics Systems

The VME bus was designed as the system backplane for a workstation, supporting one or more CPU modules along with the memory and I/O modules they used. However, no Silicon Graphics computer uses the VME bus as the system backplane. In all Silicon Graphics computers, the main system bus that connects CPUs to memory is a proprietary bus design, with higher speed and sometimes wider data units than the VME bus provides. The VME bus is attached to the system as an I/O device.

This section provides an overview of the design of the VME bus in any Silicon Graphics system. It is sufficient background for most users of VME devices. For a more detailed look at the Challenge or Onyx implementation of VME, see "VME Hardware in Challenge and Onyx Systems".

The VME Bus Controller
VME PIO Operations
VME DMA Operations
Operation of the DMA Engine