Patent ID: 8073889

Claim:
A random number generating circuit, comprising: a seed generating circuit configured to generate a seed; and a pseudo random number circuit configured to generate pseudo random numbers based on the seed generated by the seed generating circuit, the seed generating circuit including: an oscillating circuit configured to oscillate continuously or intermittently, and output a digital data sequence; a smoothing circuit configured to output time series data by controlling appearance frequencies of â€œ0â€ and â€œ1â€ in the digital data sequence outputted from the oscillating circuit; and a postprocessing circuit configured to generate one-bit seed by a computation using a plurality of bits included in the time series data, wherein the oscillating circuit has a first exclusive OR computing circuit, a first inverter circuit, a second exclusive OR computing circuit, and a second inverter circuit, coupled in series in this order, data are given to one of input ends of the first exclusive OR computing circuit and to one of input ends of the second exclusive OR computing circuit, respectively, the oscillating circuit oscillates when the data inputted to the first and second exclusive OR computing circuits have a specific combination, and appearance frequencies of â€œ0â€ and â€œ1â€ outputted from the smoothing circuit are more close to 1:1 than appearance frequencies of â€œ0â€ and â€œ1â€ in the digital data sequence outputted from the oscillating circuit.