Message arbitration in a ring interconnect system based on activity indications for each node in the ring interconnect

A method of operating a node of a ring interconnect comprising a plurality of nodes, each node connected to two other nodes to form the ring interconnect, the method comprising:

• buffering messages received from at least one device associated with the node;
• generating an activity indication for transmission to each other node of the plurality of nodes in dependence on message buffer occupancy, wherein every pair of nodes is connected by a dedicated inter-node path for that pair of nodes distinct and spatially separate from the ring interconnect, and the activity indication is transmitted along the respective dedicated inter-node paths;
• receiving the activity indications from each other node via the dedicated inter-node paths and the activity indication generated within the node;
• and
• allowing ingress of a buffered message onto the ring interconnect in dependence on the activity indications.

A ring interconnect system comprising:

• a plurality of nodes, each node connected to two other nodes to form a ring interconnect, wherein every pair of nodes is connected by a dedicated inter-node path for that pair of nodes distinct and spatially separate from the ring interconnect, each of the nodes comprising:
• means for buffering received messages from at least one device associated with the node;
• means for transmitting an activity indication to each other node of the plurality of nodes along the respective dedicated inter-node paths in dependence on message buffer occupancy;
• means for receiving the activity indications from each other node via the dedicated inter-node paths and the activity indication from the means for transmitting;
• and
• means for allowing ingress of a message from the buffer onto the ring interconnect in dependence on the activity indications.