摘要 |
A clock signal dividing circuit in which a dividing ratio is regulated by N/M (M and N are positive integers and satisfy M>N) includes: a variable delay circuit which gives a predetermined delay amount based on a control value to an input clock signal CKI to output an output clock signal CKO; and a variable delay control circuit which cumulatively adds values obtained by subtracting N from M every cycle of the input clock signal CKI, when the addition result is N or more, performs a calculation which subtracts N from the addition result to obtain a calculation result K, and calculates, to a maximum delay amount in the variable delay circuit corresponding to one cycle of the input clock signal CKI, a control value corresponding to a delay amount of K/N of the maximum delay amount to give the control value to the variable delay circuit.
|