Hardware Description Languages in the Browser§

Verilog HDL (Hardware Description Language) is standard in digital circuit design. Compiling and simulating Verilog traditionally requires installing complex toolchains like Icarus Verilog, ModelSim, or Vivado on your desktop. Online simulators exist but rely on remote servers, causing queues and requiring internet connectivity.

The NexaTools Verilog Compiler compiles and simulates Verilog code locally on your hardware. Using WebAssembly, the compilation engine runs in your browser tab, allowing you to test modules and run testbenches offline.

How Verilog WebAssembly Works§

The compiler wraps Icarus Verilog compiled to WebAssembly:

  1. Compilation: Your Verilog source code and testbench are compiled to virtual simulation executable files.
  2. Simulation: The simulator executes the design and records logic transitions.
  3. Log & Waveform Capture: System print statements and waveform data are streamed directly to the tool's log panel.

Verilog Example: Simple D Flip-Flop§

Test simple gate logic, sequential blocks, and testbenches:

// D Flip-Flop Module
module d_ff (
 input clk,
 input d,
 output reg q
);
 always @(posedge clk) begin
 q <= d;
 end
endmodule

// Testbench
module tb;
 reg clk;
 reg d;
 wire q;

 d_ff uut (
 .clk(clk),
 .d(d),
 .q(q)
 );

 always #5 clk = ~clk;

 initial begin
 clk = 0;
 d = 0;
 #10 d = 1;
 #10 d = 0;
 #10 $finish;
 end

 initial begin
 $monitor("At time %t, d=%b, q=%b", $time, d, q);
 end
endmodule

Practical Applications§

  • Academic Studies: Students can complete hardware logic design assignments instantly on any machine without toolchain installations.
  • Fast Logic Verification: Verify simple Boolean expressions, finite state machines (FSM), or decoder logic.
  • Offline Workspace: Draft and verify module layouts securely when working offline.

Access the NexaTools Verilog Compiler to compile modules and simulate digital logic circuits instantly in your browser.