Patent ID: 8504862

Claim:
A method for synchronizing two connection nodes by a reception node of the connection nodes with a clock data recovery circuit that generates a synchronization clock from input data, the method further comprising: performing a synchronization process to establish synchronization between the connection nodes based on the synchronization clock; performing a connection failure process when the synchronization is not established when a first time elapses after receiving the input data; correcting the clock data recovery circuit when the synchronization is not established when a second time elapses after receiving the input data, wherein the second time is shorter than the first time; detecting a frequency difference between the connection nodes that operate at a first communication frequency and a second communication frequency, respectively; determining whether or not the frequency difference is less than or equal to a tolerant value when the synchronization is not established when the second time elapses; and prohibiting the correcting of the clock data recovery circuit when the frequency difference is less than or equal to the tolerant value at least including determining a possibility of synchronization being established by the clock data recovery circuit.