| 摘要 |
PURPOSE:To suppress the increase in the number of wires and circuit scale even with multi-stage of pseuso random signal (PN) generating circuits by providing an NOR circuit and an integration circuit inputting two inputs to an EX-OR circuit constituting the PN signal generation circuits. CONSTITUTION:An output of SR(shift registers) 1-3 is all 0, an output of an NOR circuit 11 goes to 1 and a potential at a point (f) of an inegration circuit 12 is risen according to the time constant as shown in Fig. When the potential at the point (f) is higher than the reference potential of an OR circuit 10, a point (a) goes to 1 level as shown in A and a potential of a point (b) goes to 1 level as shown in B. When an output of any one of the SRs goes to 1, the circuit starts generation of a PN signal and when the level at a point (c) goes to 1, an output of an NOR circuit 11 goes to 0, a potential at the point (f) is changed rapidly to 0 by the operation of a diode D as shown in (f) and no effect is given to the generation of signal. In this case, even if the SR is constituted in multi- stage, input lines to the NOR circuit 11 will do with two input lines to the EX-OR circuit 6. Further, the wires through the NOR circuit, integrating circuit and the diode are as shown in Fig. |
