Spectrogram

Instantaneous Spectrum Analser Built for the Tang Nano 20K FPGA development board.

Work in Progress

Running

Flash to Tang Nano 20K

# flash volatile sram memory
make flash-sram
# flash nonvolatile memory
make flash

run isolated builds

~/oss-cad-suite/bin/yosys -p "read_verilog -sv src/[FILE_NAME].sv"

Simulation

# Run default top integration test
make sim

# Run a specific testbench 
make sim TB=pll_pixel_tb
make sim TB=sim/top_tb.v

# View simulation waveforms in GTKWave / Surfer
make waves
make waves TB=pll_pixel_tb

Clean Build Files

make clean

Set up toolchain

Check toolchain status

make check-tools

Install OSS CAD Suite

make setup-toolchain

Microphone (i2c)

SD = Serial Data

MS = Word Select (WS / LRCK) - determines left or right channel

CCK = Serial Clock (SCK / BCLK) - synchronises the bits

L/R = Channel Select (Tie to GND for left, VDD for right)

Documentation

Refer to docs/ folder

Notes

• Pixel Clock 74.25 MHz (for 1280×720 @ 60 Hz HDMI video)
• Serial Clock 371.25 MHz (5× DDR for 10:1 TMDS bit serialization)

Source Files

Clocking and Reset:

• src/pll_pixel.sv
• src/reset_sync.sv
• src/cdc_sync.sv

Video Pipeline:

• src/video_sync.sv
• src/tmds_encoder.sv
• src/hdmi_tx.sv

Top Level:

• src/top.sv

1280 x 720 = 201 600 Xbits: 2^11 = 2047 Ybits: Xbits for consitency