| 摘要 |
PROBLEM TO BE SOLVED: To provide a random number generating circuit generating a random number string by simple circuit constitution. SOLUTION: This random number generating circuit is provided with a voltage control oscillating means (VCO) outputting oscillation frequency (CLK) varying depending the fluctuation of controlled voltage (Vcnt) inputted to a control terminal (Vin), a counter means (COUNT) counting and outputting the oscillation frequency of the voltage control oscillator, and a reading means (TSB) enabled to read the output value of the counter means by a random number reading control signal (READ-RND). As the oscillation frequency outputted from a voltage control oscillator is varied large by the delicate fluctuation of the controlled voltage inputted to the control terminal and the increment of a counter is varied large consequently by this constitution, a random number string varying unexpectably and irregularly can be obtained in spite of consecutively reading data. |
