Use default 0 for nxt_info to avoid X to decimal conversion error in sim_io.py...

Closes L2SDP-864

See merge request desp/hdl!292

Use default 0 for nxt_info to avoid X to decimal conversion error in sim_io.py with tb_unb2c_test.vhd.

Resolve L2SDP-861

Closes L2SDP-861

See merge request desp/hdl!291

Rename c_sdp_W_fsub_wg into c_sdp_W_local_oscillator. Use...

Closes L2SDP-857

See merge request desp/hdl!289

added 16G ddr4 IP and created example design.

Closes L2SDP-854

See merge request desp/hdl!290

Correct c_sdp_subband_equalizer_latency = 7, to account for added msb and lsb pipeline in requantizer.

Correct c_sdp_subband_equalizer_latency = 7, to accouint for added msb and lsb pipeline in requantizer.

End with WAIT to avoid Warning: (vcom-1090) Possible infinite loop: Process contains no WAIT statement.

No functional changes. Still use quantized subband with W_subband = 16 bits and no fraction as input.