说明：  本程序为用单片机制作的占空比均匀间隔可调PWM发生器。占空比可调间隔 为0.1。即可取得占空比为0%，10%，20%……90%到100%的PWM波。该波的频率固定为1KH（周期1000微秒）。TX-1C学习板上的操作键：S2----占空比加 S3----占空比减
(This procedure for the production of single-chip, duty cycle evenly spaced adjustable PWM generator. Adjustable duty cycle interval For 0.1. Can be achieved with duty cycles of 0%, 10%, 20%...... 90% to 100% PWM waves. The frequency of this wave is fixed to 1KH (period 1000 microseconds). TX-1C learning the key board: S2---- duty and duty ratio reduction S3----)