| 摘要 |
A self-correcting synchronization signal for a communication interconnect which connects multiple units, the synchronization method including the steps of: waiting for a predetermined period of time until the next synchronization signal is due (nominal cycle period); waiting a further period of time for the absence of communications on the interconnect among any of the units, and forming a count of the passage of time during this delay (start delay); forming a synchronization signal including the count of the delay time; and sending the synchronization signal on the interconnect. Also according to this invention, a unit receiving the synchronization signal on the interconnect can update its count of time by the predetermined period of time plus the count of the delay period of time. Also according to this invention, some units can be assigned sequential access numbers, and upon recieving the synchronization signal, units without an assigned access number refrain from using the interconnect until after all units with an assigned access number have sequentially used the interconnect. This provides at last one clear opportunity for each of the units with assigned access numbers to access the interconnect in the period between synchronization signals before the interconnect is available for general access by all units. An apparatus for providing the self-correcting synchronization signal in accordance with this invention includes a cycle master unit for generating cycle start signals and transmitting them on the interconnect, and a receiving unit for receiving cycle sync signals from the interconnect and extracting the timing information to generate a local cycle synch signal.
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