Step-by-step Logisim-evolution tutorials: gates, circuits, FSMs and CPU projects.
Parity Generator and Checker in Logisim-evolution Parity bits are the simplest form of error detection: one extra bit records whether the number of 1s in your data is even or odd. Building the generator and checker is a standard lab exercise, and it is an excellent first project with XOR gates. How it works Even…
Logisim-evolution Tips and Keyboard Shortcuts Every shortcut below was verified against the Logisim-evolution v5.0.0 source and built-in help. (On macOS, use Cmd instead of Ctrl. Most shortcuts can be remapped under File → Preferences.) Simulation shortcuts Shortcut Action (Simulate menu) Ctrl+E Auto-propagate — make the circuit “live” so outputs update as you edit Ctrl+I Single-step…
7400 Series ICs vs Logisim-evolution Components If your lab course moves from simulation to a breadboard, you will meet the 7400 series: the classic TTL logic chips. Logisim-evolution ships a built-in TTL library containing faithful models of these chips, so you can prototype with the exact parts you will later wire by hand. Open the…
Instruction Decoder in Logisim-evolution The instruction decoder is the part of a CPU’s control unit that translates an opcode (the “what to do” bits of an instruction) into control signals that steer the datapath. If you are building the CPU from our simple CPU tutorial, this page shows how to decode a 6-bit opcode into…
Priority Encoder in Logisim-evolution A decoder turns a binary code into one-hot outputs. A priority encoder does the reverse: given several active inputs, it outputs the binary code of the highest-priority one. Think keyboard scanners and interrupt controllers — when multiple keys are pressed, the highest-priority key wins. The built-in Priority Encoder Step 1 —…
Subcircuits in Logisim-evolution Every Logisim-evolution project is a library of circuits. A subcircuit is a smaller circuit used as a module inside a larger one — the hardware equivalent of a function in programming. Once your designs grow past a handful of gates, subcircuits are not optional. Creating a subcircuit Select Project → Add Circuit……
Code Converters in Logisim-evolution Different parts of a digital system speak different codes: BCD for displays, Gray code for encoders, Excess-3 for old-school arithmetic. A code converter translates one into the other — pure combinational logic, and a standard lab exercise. BCD to Excess-3 converter Step 1 — Write the truth table. Excess-3 is just…
How to Export Verilog/VHDL from Logisim-evolution Your schematic is already a hardware description — Logisim-evolution can translate it into real VHDL or Verilog through the built-in FPGA Commander. This is the bridge between the simulator and the professional FPGA workflow: generate the HDL here, synthesize it in your board vendor’s toolchain. Before you start: HDL…
Shift Registers in Logisim-evolution A shift register moves bits one position per clock pulse. The building block is the D flip-flop (Memory library): chain them so each flip-flop’s Q output feeds the next flip-flop’s D input, and tie all clock pins to one Clock (Wiring library). Remember to enable ticking: Simulate → Ticks Enabled (Ctrl-K)…
Registers in Logisim-evolution A register is a row of D flip-flops sharing one clock: it stores a whole word (4, 8, 16 bits) instead of a single bit. Registers sit at the heart of CPUs — the program counter, the accumulator, and every pipeline stage are registers. Building a 4-bit register from D flip-flops Step…
