DSP28335的EPWM实例，使用EPWM1模块的中断，EPWM1A产生波形变化的矩形波，EPWM1B产生波形稳定的矩形波。EPWM2，EPWM3类似。-The DSP28335 EPWM instance, interrupt the use of the EPWM1 module, the rectangular wave EPWM1A waveform changes, EPWM1B generates a rectangular waveform stability. EPWM2, like EPWM3.