Automatic frequency control circuit and method and micro-control chip

The invention provides an automatic frequency control circuit and method and a micro-control chip, and relates to the technical field of integrated circuits. The automatic frequency control circuit comprises a low-frequency clock oscillation generator, an automatic frequency control module and a high-frequency clock oscillation generator, wherein the low-frequency clock oscillation generator is connected with a reference input end of the automatic frequency control module and is used for outputting a fundamental frequency signal, and an output end of the high-frequency clock oscillation generator is connected with a feedback input end of the automatic frequency control module and is used for outputting a high-frequency oscillation signal as a feedback signal; the output end of the frequency automatic control module is connected with the input end of the high-frequency clock oscillation generator, and the frequency automatic control module is used for generating and outputting a trimming signal according to th