Method of sampling color signal

摘要

Receiving an instruction designating a frequency f by an MPU (1), a programmable clock generator (2) generates a dot clock D which has the frequency f. The dot clock D and a horizontal synchronizing signal H having a cycle TH are supplied to a counter (3). The counter (3) counts the number N of activations of the dot clock D during the cycle TH. The activation number N is supplied to a comparator (4), together with a predetermined number K which is designated by the MPU (1). The comparator (4) compares these numbers and supplies a comparison result C to the MPU (1). The MPU (1) updates the frequency f, in accordance with the comparison result C.