| 摘要 |
PURPOSE:To achieve the application range of function of a counter by realizing a function of increasing the contents of a counter by +1 and that of decreasing them by -1 through a small number of switches according to the operation of external operation switches. CONSTITUTION:Operation signals from external operation switches S1-S5 and S7 are supplied to one-shot circuits 6-11, which output one-shot pulse signals. The pulse signal from the circuit 6 drives a quad mode counter 12. The pulse signals passed through AND gates 13-20 are inputted to +1 and -1 terminals of up-down counters 23-26, and the pulse signal from an AND gate 21 is inputted to the reset terminals of the counters 23-26 through a delay 27. The pulse signal from the circuit 11, on the other hand, drives an n-scale counter 28 to step by +1. Then, a memory part 29 is supplied with the pulse signal from the gate 21 as a read/write signal R/W. |
