New Contributor
Regular ContributorHi,
Sorry for the delay. Sorry if there is any confusion with my previous explanation. I am not referring to 2 channels but just trying to explain using serialization of two streams into one. Let me try to explain in a different way using the following example:
Assuming the input sample rate = 50MSPS. By default the required clock rate = 50MHz. However, in order to reduce the number of multipliers used, we use TDM = 2 as example to halve the multipliers. With TDM = 2, the required clock rate to the FIR IP is doubled = 100MHz.
This reduces the number of multipliers by 2x but increases logic utilization to implement the Serializer and Deserializer. At the top level, the operation of the serializer and deserializer are transparent to the user. What user need to do, is to supply 2x clock rate than the sample rate or the frequency and sample rate that you configure in IP.
Back to your configuration case, you have input sample rate = 15MSPS and clock rate = 60MHz. In other words, you are configuring the IP to implement TDM = 4. The number of multipliers utilized should reduced by 4x. During your test, you should supply input with sample rate of 15MSPS but not the 7.5MSPS because the IP is expecting 15MSPS. With 15MSPS, you would get 15MSPS at output as well. If you would like to supply 7.5MSPS, you should configure the same in the IP configuration.
Please let me know if there is any concern. Thank you.
New ContributorThank you for your response,
I feed 15MSPS input to the IP, but I get 7.5MSPS output which is half of the input rate. Please look at the attached picture.
You can see that the clock is 60 MHZ and the source_valid is asserted at a rate of 7.5MHz(period is about 133 ns which is 7.5 MHz). What am I doing wrong? Clock rate is set to 60MHz and the input sampling rate is set to 15MSPS.
I am just trying to validate the impulse response of the filter and it's all over the place it seems like the IP skipping almost all of the coefficients.
Can you try to implement similar to see if you get a similar result
Thanks!
New ContributorSorry I forgot to to attach the picture.
Here are the results as you can see the output 2 times lower than the input rate 7.5MSPS and the impulse response is all over the place.
