Semiconductor integrated circuit device, measurement method therefore and measurement system for measuring AC characteristics thereof

摘要

Disclosed is an AC characteristics measurement system that includes a flip-flop arranged in a loop of a ring oscillator; a clock generating circuit that receives a signal propagated in said loop of said ring oscillator and generates a clock signal to be supplied to said flip-flop; a delay adjustment circuit that receives a signal propagated in said loop of said ring oscillator and generates a data signal to be supplied to said flip-flop and that receives a control signal and variably controls the time difference between a transition edge of said data signal to be supplied to said flip-flop and an effective edge of said clock signal to be supplied to said flip-flop, based on said control signal; and a setup-hold changeover circuit that is provided at a preceding stage of said flip-flop and that switches the temporal before and after relation between a transition edge of said data signal supplied to said flip-flop and an effective edge of said clock signal, responsive to a control signal for performing changeover between the measurements of setup time and hold time. An AC measured value is derived from the value of the control signal at a time point of cessation of oscillation of a preset node of the loop.