This project is an educational and simplified emulator for the 8051 microcontroller. It simulates the basic functionalities of the 8051, including a subset of its instruction set, registers, program counter, and status registers. The project is designed to help students and developers understand the inner workings of the 8051 microcontroller by providing a more accessible and manageable version of the original architecture.
- Instruction Set Support: Implements a basic subset of the 8051 instruction set, including
MOV,INC,ADD,CLR,DJNZ, and more. - Register Simulation: Simulates the 8051's registers, including the accumulator (
reg_A), B register (reg_B), and register banks (reg_R). - Program Status Word (PSW): Provides a simplified version of the PSW, including flags like carry, auxiliary carry, overflow, and register bank selectors.
- Program Loader: Loads assembly-like programs from text files and supports different character encodings and file metadata display.
- Instruction Execution: Executes loaded programs sequentially, updating the state of the emulator with each instruction.
├── src/
│ ├── CheckValidCommand.java # Main class orchestrating the program execution
│ ├── RegisterBank.java # Manages the registers and program counter
│ ├── PSW.java # Manages the Program Status Word (PSW) flags
│ ├── Instruction.java # Represents an individual instruction with mnemonic and operands
│ ├── InstructionSet.java # Implements the supported instruction set and their operations
│ ├── ProgramLoader.java # Loads programs from files, with error handling and metadata support
└── README.md # Project documentation
- Java Development Kit (JDK) 8 or higher
- A text editor or IDE (e.g., IntelliJ IDEA, Eclipse)
- Git for version control
-
Clone the Repository:
git clone https://github.com/your-username/8051-emulator.git cd 8051-emulator -
Compile the Code:
javac src/*.java -
Run the Emulator:
java src.CheckValidCommand
-
Load a Program: Place your assembly-like code in a text file under the
tests/directory. When prompted, enter the filename (without the.txtextension) to load and execute the program. -
Supported Instructions: The emulator currently supports a subset of 8051 instructions like
MOV,INC,ADD,CLR,DJNZ. The program counter (reg_PC) is incremented after each instruction.
- Interrupt Handling: Implement an
InterruptControllerto simulate 8051 interrupts, allowing specific events to trigger interrupt service routines (ISRs). - Timers/Counters: Add support for 8051 timers and counters to enable time-based operations and event counting.
- I/O Ports (P0 to P3): Simulate the 8051's I/O ports for interfacing with external devices.
- Serial Communication (UART): Implement a
UARTclass for simulating serial communication. - Memory Architecture: Extend the emulator to simulate the 8051's internal RAM and ROM, including direct and indirect addressing.
- Bit-Level Operations: Support bit-level operations on bit-addressable registers and memory locations.
- Stack Operations: Implement stack operations (
PUSH,POP) to support function calls and interrupt handling. - Expanded Instruction Set: Continue adding more 8051 instructions, including logical operations, multiplication, and division.
Contributions are welcome! Please fork the repository and submit a pull request with your changes. Ensure that your code is well-documented and adheres to the project's coding standards.
- Follow Java's standard naming conventions.
- Write clear and concise comments, particularly for complex logic or algorithms.
- Use
Javadoccomments for all public classes and methods. - Keep methods small and focused; avoid long, monolithic methods.
This project is licensed under the MIT License. See the LICENSE file for details.
This project is inspired by the desire to create an accessible and educational tool for learning about microcontrollers, specifically the 8051. Special thanks to the open-source community for providing tools and libraries that make projects like this possible.