cic_decimator.xco
cic_interpolator.xco
fir_halfband_decimator.xco
fir_halfband_interpolator.xco
- Changed halfband filters to 37 taps, ~0.7dB ripple in passband, +80dB attenuation in stop band

fir_halfband_decimator.mif
fir_halfband_interpolator.mif
- Updated due to changed coefficients

toplevel_testbench.vhd
- Updated comments and control registers to reflect changes in usrp_ddr_intf_axis.vhd

usrp_ddr_intf.vhd
usrp_ddr_intf_axis.vhd
- Removed second FIR halfband stage from both TX and RX paths. Increased single FIR halfband filter stopband attenuation to 80dB. Reducing filtering path to 1x CIC and 1x halfband reduces logic utilization and latency due to filtering.
- Simplified dataflow control signal logic for the filters and added additional bypass logic. Even decimation/interpolation rates from 2 - 4094 provide the best filtering by using both the halfband and CIC filters. Odd decimation/interpolation rates from 3 - 1023 can be achieved by bypassing the halfband filter.
- Reduced bitwidths in TX path as extra bits provided almost no benefit to SNR