| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a semiconductor device which has a frequency detecting function of detecting a frequency of an input clock, and is capable of selecting drive capability by detecting the frequency of the input clock, and controlling a voltage level of an internal voltage according to the frequency of the input clock. <P>SOLUTION: A semiconductor device includes a control unit for outputting an oscillation enable signal in response to the transition of an input clock and buffering the input clock to output a comparison clock corresponding to the activation timing of the oscillation enable signal; a reference frequency generating unit outputting a reference clock having a predetermined frequency based on the oscillation enable signal; a first counting unit for counting the reference clock at the prescribed number of times; a second counting unit for counting the comparison clock at the prescribed number of times; and a comparing unit comparing the first number of clocks counted by the first counting unit with the second number of clocks counted by the second counting unit to generate a comparison signal. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
