Patent ID: 6721831
Filing Date: 2004-04-13
Classification: H04L,H04N

Abstract:
A method for controlling a bus comprising:(a1) determining whether a requesting node requesting one of a plurality of channels (CHs) and one of a plurality of bandwidths (BWs) after a given period of time following a self-identifying process due to a bus reset is one of either a new node or any one of a plurality of previous nodes which had been transmitting isochronous data before said bus reset; (b1) determining whether at least one of the previous nodes has not been reassigned one of said plurality of CHs and one of said plurality of BWs before said given period of time, based upon a control status request (CSR), if said requesting node is said new node, said step (b1) comprising: copying and storing data from a channel available register (CAR) of an isochronous resource manager (IRM) into a past channel allocation register (PCAR) of an IRM, executing a logical AND function on all bits of the PCAR and storing the logic product as a PCAR_Flag in the CSR, where said PCAR_Flag indicates whether said at least one of the previous nodes is present; executing a logical Exclusive OR function on each corresponding bit value of the CAR and the PCAR, and respectively storing a result of the logical Exclusive OR function as a channel_flag in the channel flag register (CFR), if said PCAR_Flag indicates that said at least one of said previous nodes is present; and executing a logical OR function on all bits of the CFR and storing a product of the logical OR function as a CFR_Flag in the CSR, where said CFR_Flag indicates whether said at least one of said previous nodes has not been reassigned one of said CHs and one of said BWs; (c1) assigning one of said CHs and one of said BWs to said at least one of the previous nodes, and recording a Node ID and the assigned BW in positions of a resource releasable register (RRR) corresponding to the assigned one of said CHs of said at least one of the previous nodes prior to starting an isochronous data communication, if said at least one of said previous nodes has not been reassigned one of said CHs and one of said BWs before said given period of time; (d1) assigning one of said CHs and one of said BWs to said new node and starting said isochronous data communication, if each of said at least one of the previous nodes has been reassigned one of said CHs and one of said BWs after said given period of time; (e1) reassigning one of said CHs and one of said BWs to said requesting node after said given period of time by releasing said one of said CHs and said one of said BWs assigned to said new node based upon the RRR, and starting said isochronous data communication, if said requesting node is said at least one of the previous nodes and if either one or both said one of said CHs and said one of said BWs are not available; and (f1) reassigning one of said CHs and one of said BWs to said requesting node after said given period of time and starting said isochronous data communication if said requesting node is said at least one of the previous nodes and if said one of said CHs and said one of said BWs are both available.