| 摘要 |
PURPOSE:To prevent the malfunction of an output buffer by providing a delay switching circuit between an output buffer and a function block circuit corresponding to the output buffer and a control circuit to control the delay switching circuit. CONSTITUTION:In an output buffer device, output signals (a) and (b) of function block circuits 1 and 2 are simultaneously changed from an arbitrary logical value, a waveform coincience control circuit 5 outputs a control signal CT having the contents to give relatively the delay to delay switching circuits 6 and 7. As the result, to output buffers 10 and 11, output signals A and B are given to which the signal change point is relatively dislocated by the circuits 6 and 7. Thus, when two output signals (a)-(d) or above of circuits 1-4 are simultaneously changed, the control signal CT is given to circuits 6-9 by the circuit 5, the change point of output signals A-D added to output buffers 10-13 is dislocated and the output buffers 10-13 are hourly serially operated. Thus, the malfunction of the output buffer due to the voltage drop at a power source line can be prevented. |
