MIPS Reduced Instruction Set Simulator

Overview

This project is a Java-based MIPS simulator that interprets and executes MIPS machine code using a single-cycle datapath. It simulates the internal workings of a MIPS processor and accurately executes a reduced instruction set, closely mimicking the behavior of the MARS simulator.

Features

• Executes a subset of MIPS instructions (add, sub, lw, sw, syscall, etc.).
• Reads MIPS machine code from a .text file and simulates execution.
• Manages CPU state, registers, and memory to provide an accurate simulation.
• Supports user interaction via standard syscalls, including:
  • Printing strings and integers.
  • Reading integers from user input.
  • Properly handling program exits.

How It Works

The program takes two input files:

1. Text file (.text) – Contains MIPS instructions in ASCII hex format, one instruction per line.
2. Data file (.data) – Contains raw data values in ASCII hex format, one word per line.

Execution Flow:

1. The program reads the .text file and parses each instruction.
2. It updates register values and simulates memory interactions.
3. Executes syscalls for input/output operations.
4. Maintains a log of execution state (registers, memory, program counter, etc.).
5. Prints the final output, simulating a MIPS environment.

Installation & Usage

Prerequisites

• Java 8+
• A terminal or command prompt

Running the Simulator

java -jar MIPSsimulator.jar path/to/textfile.text path/to/datafile.data

Example:

java -jar MIPSsimulator.jar EvenOrOdd.text EvenOrOdd.data

Why This Project?

• Designed to deepen understanding of CPU architecture & instruction execution.
• Useful for learning low-level programming and computer organization.
• Demonstrates ability to build a processor simulator from scratch using Java.

Future Enhancements

• Expand instruction set support.
• Implement multi-cycle and pipeline execution.
• Add GUI for interactive debugging.

Author

Logan Lapierre
GitHub | LinkedIn

License

MIT License - Free to use and modify.