Graphical IJVM Simulator

A JavaFX-based educational simulator for a simplified IJVM-like architecture.
The project visualizes key CPU datapath and control signals while executing IJVM assembly programs step-by-step.

Features

• Graphical view of CPU components (ALU, buses, registers, control signals, memory, and cache)
• Step-by-step execution of IJVM instructions
• Program loader for .txt assembly files
• Live views for:
  • Program listing
  • Stack
  • Local variables
  • Constant pool
  • Register values and control signals
• Cache simulation with selectable eviction policy:
  • FIFO
  • LRU
  • MRU
  • Random
  • LIP
• Cache metrics (hits, misses, hit rate), throughput, and utilization indicators

Supported Instructions

The assembler/parser in this project supports:

• NOP
• BIPUSH <byte>
• ILOAD <index>
• ISTORE <index>
• IADD
• ISUB
• GOTO <offset>
• IFEQ <offset>
• IFLT <offset>
• IF_ICMPEQ <offset>
• IINC <index> <const>

Project Structure

src/
  main/
    java/              # Java source files
    resources/
      images/          # UI assets
      styles/          # UI style snippets
  examples/            # Sample IJVM programs (.txt)

Requirements

• Java:
  • JDK 8 (includes JavaFX), or
  • JDK 11+ with OpenJFX installed and configured
• JavaFX runtime/module setup as needed by your JDK distribution

Run

From the repository root:

javac src/main/java/*.java
java -cp "src/main/java:src/main/resources" GUI

If your JDK requires explicit JavaFX modules, use --module-path and --add-modules javafx.controls,javafx.graphics for both javac and java.

Using the Simulator

1. Launch the app.
2. Click Input Code and select a program from src/examples/ (or your own .txt file in the same format).
3. Use Step to execute micro-operations/instructions progressively.
4. Use Reset to clear processor/memory state.
5. Optionally change cache eviction mode from the dropdown.

Sample Programs

Example inputs are available in:

• src/examples/test1.txt
• src/examples/test2.txt
• src/examples/test3.txt
• src/examples/test4.txt
• src/examples/test5.txt