PURPOSE: To prevent the occurrence of data disturbance and missing by generating a clock being 1/m of an original clock synchronously with a puncture circuit internal block timing and multiplying it with n-time.

CONSTITUTION: A punctured circuit 1 generates a frequency division clock being 1/4 (in general 1/m) of an original clock FEC CLK synchronously with a puncture circuit block timing. An n-multiple circuit 2 receives the 1/4 clock to generate an n-multiple clock MOD CLK. Then the data after punctured processing is sent as a transmission data synchronously with the clock MOD CLK. Thus, the phase between the clock and data is confirmed.