I am trying a simple Simulink model of an NCO generating a sin and cos which I then use in their own respective CIC decimator to generate quad and real output signals.
In the two product blocks (X) I get an error "The number of input rows must be a multiple of the decimation factor". I tried adding the convert blocks and specifying output type fixdt(1,20,18), but that didn’t help. The NCO is generating the proper sin and cos with amplitude +/-1 and frequency 13.5MHz with a 256Mhz sample rate.
What is the trick to getting the CIC to work? I looked at a similar Matlab Example for a GSM dds and it worked, but there was nothing special done (that I could see) to make the CIC input data types correct. Please help, I’ve spent a day chasing this problem :(I am trying a simple Simulink model of an NCO generating a sin and cos which I then use in their own respective CIC decimator to generate quad and real output signals.
In the two product blocks (X) I get an error "The number of input rows must be a multiple of the decimation factor". I tried adding the convert blocks and specifying output type fixdt(1,20,18), but that didn’t help. The NCO is generating the proper sin and cos with amplitude +/-1 and frequency 13.5MHz with a 256Mhz sample rate.
What is the trick to getting the CIC to work? I looked at a similar Matlab Example for a GSM dds and it worked, but there was nothing special done (that I could see) to make the CIC input data types correct. Please help, I’ve spent a day chasing this problem 🙁 I am trying a simple Simulink model of an NCO generating a sin and cos which I then use in their own respective CIC decimator to generate quad and real output signals.
In the two product blocks (X) I get an error "The number of input rows must be a multiple of the decimation factor". I tried adding the convert blocks and specifying output type fixdt(1,20,18), but that didn’t help. The NCO is generating the proper sin and cos with amplitude +/-1 and frequency 13.5MHz with a 256Mhz sample rate.
What is the trick to getting the CIC to work? I looked at a similar Matlab Example for a GSM dds and it worked, but there was nothing special done (that I could see) to make the CIC input data types correct. Please help, I’ve spent a day chasing this problem 🙁 #cic, #simulink MATLAB Answers — New Questions

​