PURPOSE: To execute a bit search operation for data like an infinite loop with simple circuit configuration.

CONSTITUTION: The circuit consists of a unit stage 11 comprising circuits 1-3,5 each consisting of an OR circuit and an AND circuit and a D flip-flop 4 and a unit stage 12 comprising circuits 6-8,10 each consisting of an OR circuit and an AND circuit and a D flip-flop 9, (n-1) sets of the unit stages 12 are in existence and the circuit consists of n-sets of unit stages jointed with one unit stage 11 to correspond to data consisting of n-bits. The output of the circuits 7 8,10 and the D flip-flop 9 of the (n-1)th unit stage 12 is inputted to the circuit 6 of the unit stage 12 or the circuit 1 (not shown) of the unit stage 11 when the unit stage 12 is the final stage, and the respective unit stages are formed as a ring.