Logic Circuit

Name: Logic Circuit — Download free. Digital simulator
Availability: InStock
Rating: 5 (1 reviews)
Author: Eugene Lepekhin

Logic Circuit — Free Download. Digital simulator

Logic Circuit is a program for designing and simulating digital logic circuits. It provides a graphical environment to construct circuit diagrams using standard components such as logic gates, flip-flops, memory, and input/output devices. The simulation engine allows users to test circuit behavior in real time, navigate hierarchical designs, and debug logic using built-in tools like an oscilloscope. The application supports multi-bit buses, custom subcircuits, and persistent storage of project files. It serves as a practical tool for educational demonstrations, hardware prototyping, and verification of digital systems before physical implementation.

★★★★★

5.0(1 ratings)

Download Logic Circuit (Official links)

File size: 53.4 MB

The latest version of Logic Circuit is: 2.26.09.01

Operating system: Windows

Languages: English

Developer: Eugene Lepekhin

Price: $0.00 USD (Free product)

Hierarchical Circuit Design. The program permits creation of circuits within circuits, allowing complex systems to be organized into reusable subcircuits. Each subcircuit appears as a single component in higher-level diagrams while retaining full internal logic. This method reduces visual clutter and supports modular construction of processors, controllers, and datapaths. Users can navigate through hierarchy levels during simulation to inspect signal values at any depth.
Multi-Bit Bus Support. Logic Circuit implements true multi-bit signal paths, not just single wires. A bus can carry 2, 4, 8, 16, 32, or 64 bits simultaneously, represented by a single thick line. Splitters and mergers allow extraction or combination of individual bits or bit ranges. Bus notation reduces drawing complexity for arithmetic units, multiplexers, and memory interfaces where wide data paths are standard.
Real-Time Oscilloscope Debugging. An integrated oscilloscope captures signal waveforms from any node in the running circuit. Users can set trigger conditions, adjust time scale, and observe timing relationships between multiple signals. This feature aids in diagnosing race conditions, glitches, propagation delays, and clock domain issues. The oscilloscope window updates live as simulation progresses or in single-step mode.
Standard Component Library. The software ships with a large collection of ready-to-use digital parts. Basic logic gates include AND, OR, NOT, NAND, NOR, XOR, and XNOR. Sequential elements cover D, T, JK, and SR flip-flops, latches, counters, and shift registers. Combinational blocks feature encoders, decoders, multiplexers, demultiplexers, adders, subtractors, and comparators. Memory components include RAM, ROM, and register files with configurable sizes.
Custom Subcircuit Creation. Any circuit built in the workspace can be converted into a custom component with defined input and output pins. The resulting part is stored in the user library and can be instantiated multiple times across different projects. Pin names, default values, and bus widths are preserved. This function enables building a personal library of frequently used logic blocks and accelerates large design tasks.
Input and Output Devices. For interactive simulation, the program provides virtual switches, buttons, keypads, LEDs, seven-segment displays, and text outputs. Input devices can be toggled by mouse clicks or keyboard shortcuts while simulation is running. Output devices display current logic levels, numeric values, or alphanumeric characters. These elements make the simulation behave like a physical breadboard setup.
Clock and Signal Generators. Dedicated clock sources produce periodic square waves with adjustable frequency and duty cycle. Pulse generators create single or repeated pulses triggered manually or by an internal timer. Random signal generators supply pseudo-random bit patterns for testing state machines and communication protocols. These sources are essential for synchronous circuit verification without external hardware.
Truth Table Generation. For any combinational subcircuit, the program can automatically generate a complete truth table listing all input combinations and resulting outputs. Users select the subcircuit and invoke the truth table command. The output appears in a separate window and can be exported as text or CSV. This function verifies logic correctness and documents circuit behavior for reports.
Undo and Redo System. Every editing action, including component placement, wiring, deletion, and property changes, is recorded in an undo stack. Users can revert changes step by step or restore them with redo. The history depth is configurable in program settings. This feature protects against accidental modifications and supports experimental design changes without permanent risk.
Project File Persistence. Circuits are saved in a dedicated file format with the .CircuitProject extension. The file stores all components, wires, subcircuit definitions, pin configurations, and simulation settings. Saved projects can be reopened later, shared with other users, or archived for version control. The format is XML-based and human-readable, allowing external tools to process circuit data if needed.
Multiple Document Interface. The application supports opening several circuit projects simultaneously in separate tabs or windows. Users can copy components and subcircuits between projects using clipboard operations. Each project maintains its own simulation state, zoom level, and viewport position. This capability facilitates comparison of alternative designs and reuse of proven circuit blocks across different assignments.
Signal Tracer and Probe Tool. A probe tool lets users click any wire or pin during simulation to display its current logical value in binary, decimal, or hexadecimal format. Multiple probes can be active at once, each with a color-coded label. The signal tracer highlights all paths connected to a selected node, making it easier to follow signal flow through dense layouts. This reduces debugging time in large circuits.

The Logic Circuit program began development in 2007 as an internal educational tool for university digital logic courses. The original author, Eugene Lepekhin, designed the application to address the absence of a free Windows-native logic simulator suitable for teaching. Early versions focused on basic gate simulation and simple schematic capture. The first public release appeared in 2008 on the SourceForge platform under a permissive license. Development continued through 2015, with regular updates adding hierarchical design, buses, oscilloscope, and expanded component libraries. In 2016, the project moved to its own domain, logiccircuit.org. The software is written in C# using the .NET Framework and Windows Forms for the graphical interface.