Patent ID: 6941424

Claim:
A method of backplane messaging between a sending computer board having a processor and a receiving computer board having a processor that are connected via a bus, the sending computer board including a DMA controller, said method comprising: on the sending computer board: determining the message type of a message to be sent to the receiving computer board; indexing into a send table to determine the identity of the receiving computer board; obtaining board descriptor data for the receiving computer board; having the DMA controller and not the sending board processor transfer the message to a pre-allocated buffer on the receiving computer board; having the DMA controller read back a descriptor ring address for the next message buffer on the receiving computer board; and having the DMA controller interrupt a receiver on the receiving computer board in order to notify a receiving computer board that a message has been placed into a message buffer on the receiving computer board and on the receiving computer board: searching a descriptor ring for a full message buffer containing a received message, said descriptor ring corresponding to the sending computer board; indexing into a receive table to obtain a list of virtual queues that have registered for the received message; relaying the received message, via pointer manipulation, from the message buffer to the virtual queues that have registered for the received message; and replenishing the descriptor ring with an empty message buffer.