| 摘要 |
<p>PURPOSE:To obtain a clock control input waveform for an EAROM while relieving the load of the software without causing a pulse having a period shorter than a half period of a periodic signal such as a timer output by detecting a change point of the periodic signal input so as to switch a signal switching circuit. CONSTITUTION:The periodic signal T0 such as a timer output is synchronized with a clock signal phi having a waveform shown in figure (a) by latch circuits 1-6-1-8 at first to obtain respectively output signals T1, T2, T3 having waveforms shown in figures c-e, and a leading signal U or a trailing signal D of the timer output having waveforms shown in figures f, g are detected by using the output signals T2, T3 at AND gates 1-11, 1-12. Thus, a switching circuit for the synchronizing signal T0 of the timer output and a nonperiodic signal L0 of a latch output, that is, a timer output/latch output switching circuit is incorporated on a one-chip microcomputer to realize a circuit from which a clock control input signal for an EAROM is obtained.</p> |
