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Index RVM Home Applications Challenges Hardware Architecture 
Baseboard
Host Interface Modules Software People |
The RVM Baseboard is a relatively simple board
which has "slots" for up to six smaller modules for which it provides power
and connection routing. The Baseboard which we currently use is a
6U VME size card (22cm * 23cm) which is physically compatible with a standard
VME backplane. Although our boards use the VME power pins for power
and use the VME signal pins for our Global Bus, the bus protocol is slightly
different than the normal VME bus protocol to achieve better performance.
The image on the right shows a baseboard with a single module installed (right-center). A pair of high-density connectors on each module carry power and communications between the module and the baseboard. The connectors on the right-hand side of the baseboard plug into a VME-style backplane which carries power and the Global Bus. The connectors on the left-hand side of the baseboard provide eight external comm-port connections to other baseboards. On the back of the Baseboard (not shown) there are 12
sockets for small "overlay" cards. These cards, which come in 6 varieties,
allow the developer to custom route the communications ports of each module.
This gives the developer a great deal of flexibility in choosing the topology
of his module connections. On a single Baseboard more than 2 billion
different connection schemes are possible.
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