Hi
I am trying to configure DDC (GC5016) for 20 Mhz LTE with interpolation =4 (FIR=2, CIC=2). The input rate is 30.72Msps and output rate =122.88Msps.When I try to run GCStudio , it diplays an error " fir_clk_cnt is greater than ncic" .
Kindly help resolve the same.
Ruchi Johari
Hello,
If the input rate is 30.72 and the output rate is 122.88Mhz, we have a GC5016 DUC case.
If you have selected splitIQ mode, then the PFIR interp2, CIC interp2 should allow for (with odd symmetry) 127 tap PFIR.
If you have selected 4 channel mode, then the PFIR interp2, CIC interp2, should allow for (with odd symmetry) 63 tap PFIR.
fir_clk_cnt is greater than ncic is an indication that the number of PFIR taps, is not consistent with the interpolation and splitIQ settings
I have included the GC Studio project for splitIQ, 2 channel.
Regards,
Radio Joe