PURPOSE: To easily and quickly constitute a multi-bit gray code counter by providing the gray code counter with a gray code up/down counter with a specific bit having an up/down function and a gray code counter with a specific bit.

CONSTITUTION: A 4-bit gray code up counter 82 is turned on to a state for executing counting operation by a carry-out signal CO outputted from a 4-bit gray code up/down counter 81, and when a pulse signal CLK is supplied, the counter 82 counts up by '1'. On the other hand, the carry-out signal CO from the counter 81 is becomes an 'L' level and the counter 82 stops. The counter 81 repeats up counting and down counting in each 16 pulse signals CLK, the counter 82 counts up by '1' in each 16 pulse signals CLK and 256 gray code outputs corresponding to the count value of the pulse signals CLK are obtained based upon outputs Q0 to Q3, Q7 to Q4.