Step-by-step Logisim-evolution tutorials: gates, circuits, FSMs and CPU projects.
7-Segment Display Decoder in Logisim-evolution “Design a seven-segment decoder” is a classic assignment (it appears verbatim on Chegg and in many lab manuals). A 4-bit BCD input (0–9) must light the right segments, a–g, of the display. There are two standard approaches. Method 1: Gate-level decoder Write the truth table for each segment (which segments…
SR, D, JK and T Flip-Flops in Logisim-evolution Combinational circuits forget everything the moment inputs change. Flip-flops give your circuit memory: one bit that holds its value until the clock says otherwise. They are the foundation of every counter, register, and state machine you will build. Logisim-evolution ships all four classic types in the Memory…
Half and Full Subtractors in Logisim-evolution Subtractors are the mirror image of adders and often appear in the same lab report. A subtractor computes A minus B and produces a Difference and a Borrow. Half subtractor Difference = A XOR B (same as the adder’s sum) Borrow = (NOT A) AND B — we borrow…
Half Adder, Full Adder and 4-bit Ripple-Carry Adder in Logisim-evolution Adders are the most common first lab assignment in digital logic courses: design a half adder, extend it to a full adder, then chain four full adders into a 4-bit ripple-carry adder. Here is the whole path in Logisim-evolution. Step 1: The half adder A…
Counter Tutorial for Logisim-evolution A counter increments its value on every clock tick — the heartbeat of timers, frequency dividers, and state machines. This tutorial wires a Counter to a Clock and watches it count. Step 1: Add a Counter Open the Memory library and place a Counter on the canvas. Select it and check…
Decoder Tutorial for Logisim-evolution A decoder turns an n-bit binary code into 2n outputs, with exactly one output active at a time. It answers the question “which input combination is this?” — the basis of address decoding in memories and display drivers. Using the built-in Decoder Open the Plexers library and place a Decoder. The…
Multiplexer (MUX) Tutorial for Logisim-evolution A multiplexer picks one of several inputs and forwards it to the output. The select lines choose which one: a 2-to-1 MUX has one select line, a 4-to-1 MUX has two. The rule is simple — n select bits choose among 2n inputs. Using the built-in Multiplexer Open the Plexers…
How to Build an ALU in Logisim-evolution An ALU (Arithmetic Logic Unit) is the part of a CPU that does math and logic. Logisim-evolution has no single “ALU” component — you build one from an adder, a subtractor, logic gates, and a multiplexer that picks the result. That is exactly how real ALUs are organized,…
Combinational Analysis in Logisim-evolution: From Truth Table to Circuit Combinational Analysis lets you describe what a circuit should do — as a truth table — and generates the circuit for you. It is the fastest way to go from a specification to working logic, and a great way to check hand-drawn designs. Step 1: Open…
How to Use the Truth Table in Logisim-evolution A truth table lists every possible input combination next to the output the circuit produces. In Logisim-evolution you can view the truth table of any circuit — and even edit it — from the Combinational Analysis window. What you need A saved circuit with input pins and…
