| 摘要 |
PROBLEM TO BE SOLVED: To decrease the number of elements in each delay group and obtain high resolution, and make a delay range unlimited by selecting a phase shift area which is sectioned into areas and making a phase shift by specific degrees at each time. SOLUTION: An area selection control part 205 generates an area selection control signal for selecting one of a 1st and a 2nd area which have mutually about 180 deg. different phase shift areas according to an overflow signal or underflow signal generated by a shift register 203. Then an area selection part 206 generates and outputs a drive signal for the 1st or 2nd area corresponding to the area selection control signal to a clock distribution part 207. When bit values of the shift register 203 are all shifted to '1' or '0', an overflow signal or underflow signal of specific level is generated and the area selection control signal varies to shift the phase shift area. |
