diff options
| -rw-r--r-- | cocotb_try/cic3_pdm.v | 5 | ||||
| -rw-r--r-- | cocotb_try/test_cic.py | 64 |
2 files changed, 45 insertions, 24 deletions
diff --git a/cocotb_try/cic3_pdm.v b/cocotb_try/cic3_pdm.v index 1c8ba25..e350fda 100644 --- a/cocotb_try/cic3_pdm.v +++ b/cocotb_try/cic3_pdm.v @@ -7,10 +7,11 @@ module cic3_pdm ( input wire pdm_in, // 1-bit PDM data input output wire signed [15:0] pcm_out, // Decimated PCM output output wire pcm_valid, // High when pcm_out is valid - output reg pdm_out + output reg pdm_out ); parameter DECIMATION = 64; // Decimation factor + parameter OUTPUT_SHIFT = 8; // Can tune this // Internal registers reg signed [31:0] integrator_0 = 0; @@ -60,7 +61,7 @@ module cic3_pdm ( // Bit-shift down to get 16-bit output (tune shift based on DECIMATION and stage count) pdm_out <= pdm_in; - pcm_out_r <= comb_2[31:16]; + pcm_out_r <= comb_2[OUTPUT_SHIFT + 15 : OUTPUT_SHIFT]; pcm_valid_r <= 1; end end diff --git a/cocotb_try/test_cic.py b/cocotb_try/test_cic.py index 19a17f9..ea176fc 100644 --- a/cocotb_try/test_cic.py +++ b/cocotb_try/test_cic.py @@ -5,46 +5,66 @@ import cocotb from cocotb.triggers import FallingEdge, RisingEdge, Timer, with_timeout from cocotb.clock import Clock +from cocotb.binary import BinaryValue +import numpy -async def generate_clock(dut): - """Generate clock pulses.""" +from pcm2pdm import convert +from testsignal import generate_test_tone +from test_pdm import plot_reconstruct - for cycle in range(10): - dut.clk.value = 0 - await Timer(1, units="ns") - dut.clk.value = 1 - await Timer(1, units="ns") async def drive_waveform(dut, waveform): + + high_delay = Timer(1, units="ns") + low_delay = Timer(1, units="ns") + for a_val in waveform: - dut.pdm_in.value = a_val + dut.pdm_in.value = bool(a_val) + + #dut.clk.value = 0 + #await low_delay + #dut.clk.value = 1 + #await high_delay + await RisingEdge(dut.clk) +async def collect_output(dut, samples): + + out = numpy.zeros(samples, dtype=numpy.int16) + + # wait for the PCM output + for i in range(samples): + await with_timeout(RisingEdge(dut.pcm_valid), 100000, 'ns') + #dut._log.info("PCM is %s", dut.pcm_out.value) + s = dut.pcm_out.value.signed_integer + out[i] = s + + return out + + @cocotb.test() async def my_second_test(dut): """Try running with PDM input""" - #dut.rst.value = 1 - #await RisingEdge(dut.clk) - #dut.rst.value = 0 - - pcm_samples = 10 + sr = 16000 decimation = 64 - pdm_data = [0, 0, 1] * (pcm_samples*decimation) + + sig = generate_test_tone(duration_sec=0.004, + freqs=[1000.0], noise_level=0.0, sample_rate=sr, amplitude=0.9, + ) + + pdm_data = convert(sig) cocotb.start_soon(Clock(dut.clk, 10, units="ns").start()) cocotb.start_soon(drive_waveform(dut, pdm_data)) - # wait for the PCM output - for _ in range(pcm_samples): - await with_timeout(RisingEdge(dut.pcm_valid), 100000, 'ns') - dut._log.info("PCM is %s", dut.pcm_out.value) + pcm_samples = len(pdm_data)//decimation + output = await collect_output(dut, pcm_samples) - #dut._log.info("pdm_out is %s", dut.pdm_out.value) - #assert dut.pdm_out.value == 1 + output = output / 1024 - dut._log.info("my_signal_1 is %s", dut.pcm_out.value) - assert dut.pcm_out.value == 1212 + fig = plot_reconstruct(sig, pdm_data, output, sr=sr, aspect=6.0) + fig.savefig('pdm_cocotb.png') |