Lab 5.10 - Zynq-ready BPSK BER top-level¶

Goal¶

Wrap the deterministic framed BPSK chain in a control-oriented top-level that looks much closer to the future Zynq integration path:

start -> frame bit source -> framed TX chain -> external TX sample boundary
                                            -> external RX sample boundary -> RX recovery -> BER counter -> done

This lab keeps the BPSK frame source and BER checker inside the FPGA-facing logic while exposing the sample-domain TX/RX boundary for later AD9363, FIFO or DMA wiring.

Executable HDL package¶

File	Purpose
`blocks/block_05_fpga_hdl_flow/rtl/bpsk_frame_bit_source.v`	deterministic ROM-backed frame source with `start/busy/done` semantics
`blocks/block_05_fpga_hdl_flow/rtl/bpsk_ber_counter.v`	compares recovered bits against the same frame ROM and counts total/payload BER
`blocks/block_05_fpga_hdl_flow/rtl/bpsk_zynq_ber_top.v`	top-level wrapper around source, TX chain, RX chain and BER checker
`blocks/block_05_fpga_hdl_flow/tb/tb_bpsk_zynq_ber_top.v`	self-checking top-level loopback testbench

Run from the repository root:

python blocks/block_05_fpga_hdl_flow/python/generate_bpsk_framed_loopback_vectors.py
python blocks/block_05_fpga_hdl_flow/python/generate_bpsk_rrc_tx_fir_vectors.py

iverilog -g2012 \
  -o blocks/block_05_fpga_hdl_flow/tb/tb_bpsk_zynq_ber_top.out \
  blocks/block_05_fpga_hdl_flow/rtl/bpsk_symbol_mapper.v \
  blocks/block_05_fpga_hdl_flow/rtl/bpsk_upsampler_8x.v \
  blocks/block_05_fpga_hdl_flow/rtl/bpsk_rrc_tx_fir.v \
  blocks/block_05_fpga_hdl_flow/rtl/bpsk_rrc_rx_fir.v \
  blocks/block_05_fpga_hdl_flow/rtl/bpsk_symbol_timing_sampler.v \
  blocks/block_05_fpga_hdl_flow/rtl/bpsk_hard_decision.v \
  blocks/block_05_fpga_hdl_flow/rtl/bpsk_framed_tx_chain.v \
  blocks/block_05_fpga_hdl_flow/rtl/bpsk_rx_bit_recovery_chain.v \
  blocks/block_05_fpga_hdl_flow/rtl/bpsk_frame_bit_source.v \
  blocks/block_05_fpga_hdl_flow/rtl/bpsk_ber_counter.v \
  blocks/block_05_fpga_hdl_flow/rtl/bpsk_zynq_ber_top.v \
  blocks/block_05_fpga_hdl_flow/tb/tb_bpsk_zynq_ber_top.v

vvp blocks/block_05_fpga_hdl_flow/tb/tb_bpsk_zynq_ber_top.out

Expected result:

PASS: bpsk_zynq_ber_top completed without errors

Top-level contract¶

The new top-level is intentionally small but hardware-oriented:

Signal group	Role
`start`, `busy`, `done`	one-shot frame launch and completion status
`frame_bit_count`, `preamble_count`, `start_offset`	deterministic control inputs derived from the shared Block 11 package
`tx_valid`, `tx_i`, `tx_q`	TX sample stream to a future DAC, FIFO or AD9363 TX path
`rx_valid`, `rx_i`, `rx_q`	RX sample stream from a future ADC, FIFO or AD9363 RX path
`received_bits`, `total_errors`, `payload_errors`	compact BER result interface

Why this stage matters¶

The earlier loopback testbench proved that the DSP chain works. This lab adds the system-level structure needed before a board design can use it:

a deterministic frame source rather than a direct testbench stimulus loop;
a BER counter that can later be memory-mapped or exported to software;
a clean sample-domain seam where AD9363 or AXI/DMA can attach;
explicit top-level completion semantics for automated hardware testing.

Shared frame contract¶

The top-level reuses:

Shared artifact	Role
`blocks/block_05_fpga_hdl_flow/rtl/bpsk_frame_bits.mem`	deterministic frame bits for both the source and BER checker
`blocks/block_05_fpga_hdl_flow/tb/bpsk_framed_loopback_meta.txt`	start offset, bit count, preamble count and flush assumptions

This keeps the source bits, BER reference and timing metadata synchronized across the standalone loopback and the Zynq-ready top-level.

Testbench strategy¶

The self-checking testbench connects:

top-level TX sample outputs -> top-level RX sample inputs

Then it verifies:

start launches exactly one frame;
busy becomes active during the run and clears at the end;
done asserts only after the full burst finishes;
the BER counters report zero total and payload errors.

First hardware-facing interpretation¶

This top-level is still synthetic, but it is now structurally aligned with the future board path:

frame source / control -> TX samples -> AD9363 TX -> RF path -> AD9363 RX -> RX samples -> BER counters

That is the correct place to attach AXI-Lite registers, DMA, BRAM control or board-specific clock/reset logic in the next step.

Report checklist¶

[ ] State the meaning of start, busy and done.
[ ] Show how frame_bit_count, preamble_count and start_offset are supplied.
[ ] Show the exposed TX and RX sample boundaries.
[ ] Include the final BER counter values.
[ ] State the next integration step: AXI-Lite registers, DMA hookup or AD9363 connection.

Engineering conclusion template¶

The deterministic BPSK modem chain now has a Zynq-ready top-level with a one-shot start interface, explicit completion status and BER counters.
The frame source and BER checker reuse the same ROM-backed bit sequence, so the test remains deterministic.
This is the correct integration anchor before connecting the design to AXI control, DMA or the AD9363 sample path.