I am using CIC decimator from system generator. First, I developed a model in a separate file and tested it for different input data. Then i moved this model to a different file and a bigger model of complete transmitter and receiver, with almost the same input, the output of CIC decimator is not good. Instead of decimating and producing the same output as input (with of course less no. of samples), it is giving an output with very large negative values only. Please guide how can i correct this. The output of first case and second case are attached. The configuration of CIC decimator is as follows.