介绍了28335内部的PWM波产生模块，确定了方波的周期以及占空比的设置细节！-Introduced the 28335 internal PWM wave generating module, to determine the details of the configuration of the cycle and the duty cycle of the square wave!

AD9833是一款DDS函数信号发生芯片，通过51单片机的控制可以产生不同频率的正玄波、方波和三角波-AD9833 is a DDS Function generator chip, the microcontroller controls through 51 different frequencies can produce sine wave, square wave and triangular wave