testbench(xilinx)

代码说明：

  Testbench 不仅要产生激励也就是输入，还要验证响应也就是输出。当然也可以只产生 激励，然后通过波形窗口通过人工的方法去验证波形，这种方法只能适用于小规模的设计(The Testbench not only to generate incentives to input, verify that the response is output. Of course, can only produce Incentive, and then the waveform by the waveform window by artificial means to verify, this method is only applicable to small-scale design)