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Modifying the FPGA firmware

Posted: Mon Aug 22, 2016 4:30 am
by adam
Hi all

I would like to modify the FPGA firmware to perform some signal processing on the received signal. It looks like I should place my custom logic after the iq_correction block in bladerf-hosted.vhd. Does this sound correct?

The interface looks simple enough. The block's input and output will be the IQ data + a valid signal. I plan to implement a decimator, so the output sample rate will be lower than input sample rate to my block. Will this cause problems downstream? i.e. does anything downstream of the iq-correction block assume that the data rate stays the same all the way through?

Also - the readme says to build it with Quartus 15 and the source is not compatible with earlier versions. But, is it compatible with later versions? i.e. Quartus 16?

Thanks,
Adam

Re: Modifying the FPGA firmware

Posted: Mon Aug 22, 2016 10:50 am
by bpadalino
That is the correct spot to place what you want.

Nothing downstream expects anything at a certain rate so you can feel free to decimate. Just the IQ + valid is required.

You may have to change timeouts on the host side if you decimate significantly, but other than that you should be good.

Brian