在ADI公司dsp芯片sharc21489中通过DMA实现延时功能，配合sigma for sharc使用,输入有两个参数，一个是延时时间，另一个是延时需要放在片外那个地址。-In sharc21489 delay by the DMA function, with sigma for sharc use, there are two input parameters, a delay time, and the other is the delay needs to be placed chip that address