Signal resynchronization apparatus having capability to avoid data corruption

Abstract

An apparatus for resynchronizing data signals by using dual port data buffer storage, which prevents data corruption and subsequent system disruption from happening by employing a mechanism to keep an adequate distance between read and write address pointers. An input unit receives an incoming data stream having a cyclic data structure of N bytes. A data writing unit sequentially writes each data word of the received data stream into a storage unit with a capacity of 2N bytes in synchronization with a first clock. A data reading unit sequentially reads out each data word from the storage unit in synchronization with a second clock. A detection unit tests whether the write and read address pointers have come within a predetermined threshold distance. A relocation unit moves the read address pointer by N bytes to increase the distance between the read and write address pointers, when the detection unit has detected that the write and read address pointers have come within the threshold distance. An outputting unit transmits to an external destination the data words read out by the data reading unit.