Patent ID: 7315213
Filing Date: 2008-01-01
Classification: H03K,H03L

Abstract:
1. A semiconductor device adjusting a delay time before an input signal is outputted after being inputted, the semiconductor device comprising: a phase comparing circuit comparing phases of a reference clock signal and a feedback clock signal; and an oscillation circuit outputting the feedback clock signal and a delay control signal which controls the delay time based on a result of the comparison in said phase comparing circuit; and a delay circuit delaying the input signal by the delay time according to the delay control signal to output the delayed input signal, wherein said oscillation circuit comprises: a plurality of independent internal oscillation circuits with different oscillation frequencies, the oscillation frequencies being controllable based on the result of the comparison in said phase comparing circuit; and a selecting circuit selectively outputting one of outputs of the plural internal oscillation circuits as the feedback clock signal.