how plot the response at the output of each integrator stage and each comb stage of CIC decimation filter?

R = 8; % decimation factor

M = 1; % differential delay

N = 9; % number of sections

hm = dsp.CICDecimator(R,M,N);

Answer 1

[Poorna]

Hi Sola Miatudila,

I understand that you want to plot the output of each integrator and the comb stages of the CIC Decimator.

Currently there is no official API available to do that. However, you have the option to implement your own CIC Decimator, allowing you to access all the intermediate outputs.

If you are familiar with the inner workings of a CIC Decimator, you can create your own implementation. Alternatively, you can use the original CIC Decimator implementation by MathWorks and make modifications to it. You can find the source code of the CIC Decimator by right-clicking the function "dsp.CICDecimator(R,M,N)" in your code and selecting "Open dsp.CICDecimator".

Now do the following:

• Rename the class to some other name like “Custom_CICDecimator” to avoid confusion, also change the name in the constructor.
• Edit the “stepImpl” function to add the intermediate outputs after each stage to an array.
• Modify “stepImpl” function to return this array as output.
• Now you can use your modified CIC Decimator as follows:

        hm = Custom_CICDecimator(R,M,N); 

For more information about CICDecimator, please refer to the following documentation:

https://www.mathworks.com/help/dsp/ref/dsp.cicdecimator-system-object.html

Hope this Helps!

Best regards,

Poorna.