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Altera_Forum
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18 years ago

MegaCore FFT in Quartus

I'm working on using the MegaFunction FFT in Quartus on an Altera DE2 board, but have had issues finding documentation of the inputs/outputs to the function. I've scoured these forums for a while, bu...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
18 years ago

I'm stuck. I attached the source and would appreciate if anyone could comment on a few issues:

1. I get a "can't place pins" error on the audio_in and audio_out, which results in a "can't fit design in device" error. I double-checked the locations in the assignments editor, and everything is tied to the right pins (AUD_DACDAT, AUD_ADCDAT). I also changed the Pin I/O settings so nCEO is set as normal I/O instead of programming pin. I'm using Quartus 7.1 Build 178 so I don't have the Quartus 6.0 error.

2. I was not able to set sourcevalid successfully. If you look at the source, I commented out a line which would set the sourcevalid since I was getting a "multiple constants" error. The only other time that sourcevalid is used is in the port map. Am I doing something wrong or is there a workaround?

3. Since I can't test it, I'm not 100% sure if the thing works conceptually.

Thanks!