| 摘要 |
PURPOSE: To make a sequence to be hardly deteriorated and to prevent it from being statically a nonrandom characteristic by providing, at least, two basic shift registers, presetting the initial content of the register by an internal key and making them feedback each other through a changing member built in a feedback loop. CONSTITUTION: The output terminal 2 of the register 3 is connected to the input terminal 26 of the register 1 via an AND gate 5, and the output terminal 4 of the register 1 is connected to the input terminal 27 of the register 3. Two registers 33 and 34 are fed back to each other, an output 20 of the register 33 is fed back to an input 7 of that register, and also an output 9 of the register 34 is fed back to that its input 14. A dual stable counter 10 being a nonlinear element is connected to the output terminal 9 of the register 34. A sequence fetched from the register 1 in a linear method is changed by a bit fetched from the intermediate output terminals of two separated registers 33 and 34. |
