I'm using the v5.1 coregen fir, decimate by 2, two channel operation to process my I/Q. My system clock is 56 Mhz and the I/Q data rate is 500 ksps so I'm sure the latency is okay for the single dsp48 mac engine. Anyway, the output I get is misaligned, that is if I input a complex sinusoid and then plot the output on an x-y plot I get an ellipse instead of a circle.
To figure out the misalignment I changed to input the same I sample on both channels expecting that I should get the same output on both channels. The outputs don't match. AND its not that they are shifted in time, they just do not match. I get the same result with modelsim and in my system.
Does anyone have a working two channel fir example with testbench that I can use as a reference? Any ideas on why the channels would be misaligned?
Thanks, Clark