A tour of Logix

A short walk through Logix for new users: what it is, what's on the screen, and the path from an idea to a programmed board. Each part links to the page with the details.

What Logix is

"The Arduino experience, for FPGAs." If you've used the Arduino IDE, Logix will feel familiar: you write code, click Verify to check it, and click Upload to put it on your board. The difference is the language: you write Verilog, which describes hardware, instead of C++.

Why it's easy to start

• One installer. No Python, package managers or toolchain setup.
• The FPGA tools come by themselves. On its first start, Logix downloads the open source FPGA tools it needs. You never have to learn or install them yourself.
• Learn by example. More than a hundred examples for over a hundred boards.

To get it, see Installing Logix.

The toolbar

Button	What it does	Shortcut
Verify	Checks the design and builds it	Cmd+R
Upload	Builds the design and programs the board	Cmd+U
Run Tests	Runs the project's testbenches	Shift+Cmd+T
Simulate	Shows the signals in GTKWave	Option+Cmd+T
Stop	Stops whatever is running	Cmd+.
Board list	Picks your board; boards plugged in come first

Below the toolbar are a tab for each file, the editor, and the output with a status line that says what Logix is doing. Mistakes in the grammar, like a missing ;, are underlined as you type.

A project is a folder

The main file is always main.v, and its module is named main. Other Verilog files and the board's pin file show up as tabs, and testbenches end with _tb.v. New projects go to ~/Documents/Logix.

This is blinky, the design a new project starts from. A counter counts clock cycles, and its top bit drives the LED, so the LED blinks:

module main (
    input sys_clk,
    output led
);
  reg [23:0] counter = 0;
  always @(posedge sys_clk) counter <= counter + 1;
  assign led = counter[23];
endmodule

More in Using Logix.

Start from an example

File > Examples… lists the examples for each board, with a search box. Every board's list starts with Bare Minimum: the board's pins and a design that does nothing yet, to start from scratch. Choosing a board never changes your files.

Verify: check, build, report

Verify checks the design for common mistakes, builds it for your board, and reports how much of the FPGA it uses and how fast it can run. A mistake is marked on its line; hover over the mark to read it, or click the file:line link in the output to jump there.

Upload: put it on the board

Plug the board in by USB. Next to the board list, Logix says Connected. Click Upload: Logix builds the design, shows how much of the FPGA it uses, and programs the board. If it can't find the board, Tools > Connected Devices… shows what's plugged in, and Troubleshooting has tips.

Test without a board

A testbench drives your design's inputs and checks its outputs, with no board needed. Run Tests runs them all and shows each result; Simulate shows the signals over time in GTKWave. Most examples come with a testbench. More in Testbenches and simulation.

See what you built

Project > Show Diagram (Shift+Cmd+D) draws your design's modules and signals: a good way to check that the hardware you described is the hardware you meant.

Your first blink

1. File > New.
2. Pick your board.
3. Verify.
4. Upload. The LED blinks.

The Quick start walks through it step by step.