05-29-2012 04:05 PM
I'm working with the Avnet Getting Started Guide reference design for the ML605+FMC150 and am having difficulty obtaining a usable siganal from the ADC. I'm trying to send the signal from the ADC directly to the DAC (bypassing the DUC/DDC), and also look at the signal from the ADC in Chipscope.
To send the signal to the DAC I've written the following code under the "Output serdes and LVDS buffers for DAC data" section:
d1 => adc_dout_i(i + 8),
d2 => adc_dout_i(i),
while commening out the origional code (dac_din_i(i)).
The output from the DAC and the waveform on chipscope are identical; screenshots of the Chipscope output are attached. (I've commented out the Chipscope code that came with the reference design and inserted my own chipscope core). The signal I'm using (adc_dout_i) varies with the input to the ADC (frequency and amplitude), but is highly distorted. Could you let me know if adc_dout_i (or q) is the correct signal to use for this purpose, or what other problems could cause this distortion?
I'm using Project Navigator 13.2, 64 Bit version and I've also attached the code I'm using.