说明：  STM32F0 输出3路相同频率PWM波，占空比相位输出任意可设置，例如三个通道输出，等第一通道的占空比输出完后，第二通道的占空比才输出，然后等二通道输出占空比完成后第三通道才输出。
(STM32F0 outputs 3 channels of the same frequency PWM waves, and the duty cycle phase output can be set at will. For example, the duty cycle of three channels is output. After the duty cycle of the first channel is output, the duty cycle of the second channel is output, and then the third channel is output after the duty cycle of the second channel is finished.)