PURPOSE: To provide a gray-code single transition counting circuit device which is exceedingly suitable for higher counting speed, lower power consumption, smaller occupying area, and ASIC compiler program.

CONSTITUTION: A count signal is supplied to a counting line 436. Since transition counting is changed in response to the count signal and has a plurality of bits supplied from at least one first module 404 and at least one second module 404. The first and second modules 404 and 406 are alternately connected in series with an input module 402 so that one of the modules 404 and 406 can have inputs 460a and 466a respectively connected to the 'invisible' bit output 420 and grounding conductor 468 of the input module 402 and each additional module 406 can have inputs 482a and 488a connected to the outputs 472a and 478a of each relational first module 404.