chapter  V
V
Pages 36

Before the coming of CompactPCI technology, VME reigned supreme in the worlds of high-end telecom, military, industrial, and other real-time computing systems. VME has a huge installed base. VME uses a completely memory mapped scheme, and every device can be viewed as an address, or block of addresses. Addresses and data are not multiplexed - it’s an asynchronous bus, so data can be transferred to each board at its own optimum speed. A typical transfer consists of an arbitration cycle (to gain bus control), an address cycle (to select the reg­ ister) and the actual data cycle. Read, write, modify and block transfers are supported.