| 摘要 |
PURPOSE:To output a pseudo random number with simple constitution by using a shift register having a feedback circuit so as to generate a numeral being a base of a random number at each prescribed interval, extracting the signal by a random number request signal, storing part or all bits into a register and outputting the result. CONSTITUTION:A shift pulse is inputted to shift registers 11, 12, 13 and 14 from a shift clock generating circuit 18 at a prescribed time interval. Thus, the shift register is shifted through a feedback circuit comprising exclusive OR circuits 15, 16 and 17 and the output is an M series code whose level is varied at a prescribed time interval. When a random number request signal is generated, the output value of the low-order 8-bit of the shift registers 11, 12 is stored by the register 19 to form a random number output. Since the shift register in use has 12bits, the low-order 8-bit is outputted at the same probability for the value to be taken and a random series with high uniformity is obtained. |
