Patent ID: 7747771

Claim:
A system comprising: a ring bus configured to convey transaction data; a plurality of nodes coupled to said bus, wherein each of the nodes receive transactions on the ring bus in a predetermined order; and a ring control unit configured to place transactions on the bus; wherein each of the nodes coupled to the ring bus is configured to: receive a first transaction conveyed on the ring bus; process the first transaction with a given latency if the node that receives the first transaction is a node to which the first transaction is targeted; and process the first transaction with the given latency if the node that receives the first transaction is not a node to which the first transaction is targeted; wherein the ring control unit is configured to periodically place an idle transaction on the ring bus; wherein a first node of the plurality of nodes forwards a completion control packet on the ring bus, responsive to receiving a control packet which is identified as corresponding to an idle transaction; wherein register access transactions comprise either determinate latency register access transactions or indeterminate latency register access transactions, and wherein a latency of a particular transaction is represented by a difference between a time the particular transaction is placed on the bus by the ring control unit and a time a response corresponding to the particular transaction is received by the ring control unit; wherein in response to a first node determining a particular register access transaction received by the first node is targeted to the first node and is an indeterminate latency transaction, the first node is configured to: modify a received control packet which corresponds to the particular register access transaction, wherein the modified control packet indicates the modified control packet corresponds to an idle transaction; and forward the modified control packet on the ring bus.