To provide a technology of measuring the phase difference between synchronous signals with high accuracy.

This system has an integrated circuit device for comparing the relative phases of first and second signals with each other with very high accuracy. This system has a first input for receiving the first signal provided with a first edge and a second input for receiving the second signal provided with a second edge. A first delay chain has at least one first delay element, and a second delay chain has at least one second delay element. At least one symmetric flip flop has the first and second inputs connected to each output tap of the first and second delay elements, and the output of the flip flop indicates which of the first and second edges reaches the first and second inputs first.