Method to prevent net update oscillation

Abstract

A method for preventing net update oscillation of a bus bridge by competing net update messages is presented. The method includes the steps of (a) determining whether a particular portal is a coordinator on its local bus; and proceeding to step (b) (i) if the particular portal is a coordinator, otherwise, proceeding to step (b) (ii); (b) (i) determining whether the particular portal finds a net update collision on its local bus; and proceeding to step (c) if the net update collision is found, (b)(ii) determining whether the particular portal receives an UPDATE_ROUTE message from another portal that is a coordinator on the local bus; and proceeding to step (c) if the UPDATE_ROUTE message is received; (c) setting a global net_update bit to one by a lock procedure, (d) verifying whether the lock procedure in step (c) has been successfully performed by determining whether the net_update bit has been set to one,(e) performing one of: (i) discarding the net update if it has been determined in step (d) that the lock procedure in step (c) has not been successfully performed, and (ii) processing the net update according to IEEE1394.1 bridge standard and setting the net_update bit to zero.