How to Build a Custom FPGA Prototype on a UNI‑SIP Board in One Weekend

You’ve probably heard the phrase “time is money” a lot in the lab, and when a deadline looms, the only thing you want is a working prototype by Monday. That’s why a weekend‑long FPGA build on a UNI‑SIP board is not just a nice‑to‑have—it can be the difference between a successful demo and a sleepless night. I’m Dr. Maya Patel, and I’ll walk you through a practical, no‑fluff plan that gets you from an empty board to a blinking LED in under 48 hours.

Why a Weekend Build Matters

In academia and industry alike, we often juggle multiple projects, teaching duties, and grant paperwork. A fast, repeatable prototyping flow lets you test ideas quickly, iterate, and keep the momentum going. The UNI‑SIP board was designed for exactly this purpose: a compact, low‑cost platform that supports a range of FPGA families while staying friendly to beginners and seasoned engineers alike. When you master a weekend workflow, you free up the rest of the week for deeper research, documentation, or that much‑needed coffee break.

What You Need

Board and accessories

• UNI‑SIP development board (the 5‑layer version is my favorite because it gives you extra I/O without extra cost)
• Micro‑USB cable (for power and JTAG programming)
• A small breadboard and a few jumper wires (for quick peripheral testing)
• A USB‑to‑UART adapter (optional, but handy for serial debug)

Software tools

• Vivado WebPACK (or Intel Quartus Lite if you’re using an Intel FPGA)
• Uni‑SIP Board Support Package (BSP) – download from the UNI‑SIP Prototyping Hub page
• A text editor you love (VS Code, Sublime, even Notepad++)
• A basic logic simulator like ModelSim (free version works fine)

All of these are free or have free tiers, so you won’t need a corporate license to get started.

Step 1: Plan Your Logic

Before you open any IDE, spend 30 minutes sketching what you actually need. For a weekend demo, keep the design simple: a counter, a few LEDs, and maybe a UART echo. Write down the I/O pins you’ll use, the clock frequency, and any external modules (e.g., a temperature sensor). This “paper‑first” step saves you from chasing a missing pin later.

Pro tip: The UNI‑SIP board has a dedicated 50 MHz crystal. If you need a different speed, you can use the PLL (phase‑locked loop) inside the FPGA, but for a quick test stick with the native clock.

Step 2: Set Up the Toolchain

1. Install Vivado WebPACK (or Quartus Lite) and run the installer as administrator.
2. Add the UNI‑SIP BSP to the tool’s library path. The BSP includes pin constraints and board‑specific scripts, so you don’t have to write a .xdc file from scratch.
3. Verify the JTAG connection: open the hardware manager, click “Open target,” and you should see the UNI‑SIP board listed as “xc7a35t‑…”. If not, reinstall the USB driver that comes with the board.

A quick sanity check at this stage is to run the “Hello World” example that ships with the BSP. If the LEDs blink in the pattern shown in the board manual, you’re ready to move on.

Step 3: Write and Simulate Your Design

Create a new project called weekend_demo. Add a single Verilog file named counter.v:

module counter (
    input  wire clk,
    output reg  [7:0] leds
);
    reg [23:0] div;
    always @(posedge clk) begin
        div <= div + 1;
        if (div == 0) begin
            leds <= leds + 1;
        end
    end
endmodule

This tiny module divides the 50 MHz clock down to a visible LED blink rate. Save the file, then write a simple testbench (counter_tb.v) that drives clk and checks the leds output. Run the simulation in ModelSim; you should see the LED count increment every few thousand cycles. If the simulation passes, you have a functional core.

Step 4: Synthesize and Generate Bitstream

Back in Vivado, click “Run Synthesis.” The tool will translate your Verilog into a netlist and map it onto the FPGA’s resources. When synthesis finishes, run “Implementation” and finally “Generate Bitstream.” This step usually takes 10‑15 minutes on a modern laptop.

If you hit a “resource exceeded” warning, double‑check that you didn’t accidentally enable unused IP cores. The UNI‑SIP board’s small FPGA has limited LUTs, so keep the design lean.

Step 5: Load the Bitstream onto the UNI‑SIP Board

1. Open the hardware manager, connect to the board via JTAG, and click “Program Device.”
2. Browse to the generated .bit file and press “Program.”
3. When the progress bar hits 100 %, the board will automatically reset and start running your design.

You should now see the eight LEDs counting up in binary. If they stay dark, double‑check the pin assignment file (.xdc). The BSP pins the LED array to IO_L13P_T2_MRCC_35 through IO_L14N_T2_SRCC_35; a typo here is a common pitfall.

Step 6: Test and Debug

Connect the USB‑to‑UART adapter to the board’s serial header and open a terminal at 115200 baud. If you added a UART echo module, type a character and watch it bounce back. For the simple counter, you can use an oscilloscope or a cheap logic probe to verify the 50 MHz clock is still present on the CLK pin.

When something doesn’t work, the easiest place to look is the Vivado “Report” files. They tell you exactly which pins are used, timing violations, and any warnings that might have been ignored. A quick “clean and rebuild” often clears up stray synthesis artifacts.

Quick Tips for a Smooth Sprint

• Keep a checklist. Write down each step (install, BSP, example test, design, synth, program) and tick it off. It feels satisfying and prevents you from skipping a crucial verification.
• Use version control. Even a single‑file Git repo helps you roll back if a change breaks the build.
• Don’t over‑engineer. The goal is a working prototype, not a production‑ready ASIC. Stick to the essentials and add complexity later.
• Take short breaks. A 5‑minute walk after each major step keeps the mind fresh and reduces the chance of simple copy‑paste errors.
• Leverage the community. The UNI‑SIP Prototyping Hub forum has a “Weekend Projects” thread where people share their .bit files and pin maps. A quick glance can save you hours of debugging.

By following this plan, you can turn a blank UNI‑SIP board into a functional FPGA prototype before the Sunday night pizza arrives. The real power of the workflow is that once you’ve built the first demo, the next one is just a matter of tweaking the Verilog and re‑programming. That’s the essence of rapid prototyping: iterate fast, learn fast, and keep the excitement alive.