Clock switch device and microcontroller

摘要

The clock switch device of the present invention includes: a clock detector for receiving a plurality of clocks and clock selection data designating a clock to be selected, detecting whether or not the clock designated by the clock selection data among the plurality of clocks changes in signal level, and outputting the result as a detection signal; a control register for holding and outputting the clock selection data when the detection signal indicates that the clock designated by the clock selection data changes in signal level; and a selector for receiving the plurality of clocks and selecting a clock corresponding to the output of the control register among the plurality of clocks.