US Patent 8072253 Clock adjusting circuit and semiconductor integrated circuit device

Disclosed is a clock adjusting circuit comprising a phase shifter that receives a clock signal and variably shifts, based on a control signal, respective timing phases of a rising edge and a falling edge of the clock signal; and a control circuit that supplies the control signal to the phase shifter circuit before each edge is output; wherein the clock signal, in which at least one of a period, a duty ratio, jitter and skew/delay of the input clock signal is changed over an arbitrary number of clock cycles, is output.