A web-based, visual LEGv8 instruction set simulator designed for educational purposes. This tool helps students and enthusiasts understand the flow of data and control signals within a single-cycle LEGv8 processor datapath for each instruction.
Legv8-Simulator Screenshot
- 🧠 Visual Datapath: Interactive SVG diagram shows how each LEGv8 instruction flows through the datapath.
- 🎞 Real-Time Animation: Control and data signals animate as instructions execute.
- 🔁 Step-by-Step Execution: Observe internal states per instruction.
- ✍️ Code Editor: Simple in-browser editor with line numbers and import support.
- 🧪 Parser & Validator: Validates syntax, resolves labels, and logs errors before execution.
- 🔍 Optional State Inspection: (if implemented) View contents of all registers and memory locations.
- Open the Simulator: Simply open the
index.htmlfile in a modern web browser (Chrome, Firefox, Edge). - Write or Import Code:
- Type your LEGv8 assembly code directly into the code editor.
- Or, click the "📤 Import Code File" button to load an assembly file (
.s,.asm,.txt) from your computer.
- Compile: Click the "⚙️ Compile" button. This will:
- Parse your assembly code.
- Resolve any labels used in branch instructions.
- Validate the syntax.
- Report any errors or a success message in the Log panel.
- Execute: If compilation is successful, the "▶ Execute" button will be enabled.
- Click "▶ Execute" to run the entire program with full animation.
- (Optional, if implemented) Use the "Step" button to execute one instruction at a time.
- Restart: Click the "↺ Replay" button to stop the current execution, clear the animation, and reset the simulation state, allowing you to run the code again from the beginning.
| Type | Supported Mnemonics |
|---|---|
| R-Type | ADD, SUB, AND, ORR, EOR, ADDS, SUBS, ANDS |
| D-Type | LDUR, STUR |
| I-Type | ADDI, SUBI, ANDI, ORRI, EORI, SUBIS |
| B-Type | B, BL |
| CB-Type | CBZ, CBNZ |
| B.cond | B.EQ, B.NE, B.GT, B.LT, B.GE, B.LE, etc. |
💡 Syntax Notes:
- Use
//for comments.- Define labels with
LabelName:.- Registers:
X0–X30,XZR.- Immediates: decimal (
#10).
👉 Live Version: https://hcmus-hqhuy.github.io/LEGv8-Simulator/
Just open in any modern browser — no setup required!
- @HCMUS-HQHuy – Huỳnh Quốc Huy
- @77x17 – Phan Ngưng
💬 Found a bug?
🧠 Want to add a feature?
🛠 Submit a PR or open an issue!
👉 Issues
👉 Pull Requests
LEGv8 is a simplified ARMv8 architecture model used in education. This simulator is not intended for production ARM development.