I use DAC with DMA to ouput a sine wave. The DAC is triggered from exti9. It can output a perfect sine wave now. But I want to sync the wave's zero-crossing with a pin's rising edge. So, I put the start signal in the rising edge interrupt handler. And make my sine table starting from 0. But when I probing the DAC output and the rising edge signal, I found sometimes the DAC output is apparently delayed to the rising edge, sometime the delay is about 10ms!!!! So, is it normal to use DMA with DAC?