PURPOSE: To simplify the circuit constitution and to attain the cost reduction for a gold code generated by extracting M series codes out of a feedback input part to a multi-stage shift register at a code generating part.

CONSTITUTION: A main control part 9 delivers signals I1∼I4 and performs generation of M series codes as well as execution of the synthesizing process of gold codes. When the data on a logic "1" of a data bus D0 is set at a latch circuit after a start signal I1 is transmitted, the next latch circuit is set to open a gate circuit. Thus clocks are supplied all at once to each flip-flop of code generating parts 1A and 1B respectively. Then different M series codes are extracted from each code extracting part. These M series codes are synthesized by a code synthesizing circuit 5, and gold codes are produced.