一个基于89c51单片机的简单波形产生器的程序，能够输出方波，梯形波，三角波，锯齿波和正弦波的波形，并可以按钮切换波形！-A 89c51 microcontroller based on the simple waveform generator procedure, can output a square wave, trapezoidal wave, triangle wave, sawtooth and sine waveforms, and waveform switching for the button!