Stack-Machine CPU Simulator

Description

Stack-Machine CPU Simulator: Interactive Architecture & Compiler Software

Stack-Machine CPU Simulator – Understanding how stack-based computers process expressions without explicit register operands is a crucial foundation in low-level engineering. The Stack-Machine CPU Simulator offers an intuitive visual software environment designed to model zero-address computer architectures in real time.

Unlike classic register-based CPUs (such as MIPS or RISC-V), stack machines operate implicitly on data stored in LIFO (Last-In, First-Out) data structures. This simulator brings those implicit operations to life, allowing users to write stack bytecode, observe memory mutations, and track evaluation paths down to individual clock cycles.

Fundamental Architecture & Execution Model

The Stack-Machine CPU Simulator models a clean, 32-bit zero-address architecture where arithmetic, logic, and control operations derive their operands directly from the stack pointer.

1. Push Phase: Data moves from instruction memory or RAM directly onto the Top of Stack (TOS).
2. Implicit Decoding: The ALU pulls operands from TOS and Next-on-Stack (NOS) without needing register index addresses.
3. Execution & Shrink: The operation runs, pops the inputs, and writes the resulting evaluation directly back onto the stack.

By abstracting away register management, this software provides a pure view into expression trees, postfix evaluation, and virtual machine execution engines.

Key Features & Capabilities

• Dynamic Evaluation Stack Visualizer: View live mutations of the stack array, including highlighted TOS, NOS, and stack pointer (SP) registers on every instruction cycle.
• Zero-Address Instruction Set (ISA): Run essential stack commands including PUSH, POP, ADD, SUB, MUL, DIV, AND, OR, XOR, alongside stack manipulation primitives (DUP, SWAP, DROP, ROT).
• Subroutine & Call-Stack Inspection: Dedicated call-stack window models return addresses, frame pointers, and local variable slots for nested function execution.
• RPN & Postfix Expression Compiler: Convert standard infix expressions (e.g., (A + B) * C) into Reverse Polish Notation and execute the output machine code automatically.
• Flexible Memory Management: Dedicated data memory region allows for direct memory load and store operations (LOAD, STORE) using stack-derived addresses.
• Single-Step & Variable Clock Controls: Advance cycles manually to inspect control signal states or run automated scripts at adjustable execution frequencies.
• Integrated Code Editor & Disassembler: Write clean stack assembly, compile directly into machine hex codes, or inspect raw binary dumps with built-in syntax highlighting.

Detailed Technical Specifications

Target Audience & Core Use Cases

Computer Science Students & Educators

Visualize how compilers compile high-level programming logic down to execution trees. Learn how evaluation stacks evaluate complex algebraic expressions without requiring dynamic register allocation algorithms.

Virtual Machine & Language Engineers

Analyze how stack-based bytecodes operate under the hood. Perfect for developers building language runtimes, domain-specific languages (DSLs), or custom interpreters modeled after the Java Virtual Machine (JVM), WebAssembly (Wasm), or Forth runtime systems.

Embedded Systems & Reverse Engineers

Study how lightweight hardware implementations reduce silicon footprint by omitting multi-port register files, making stack architectures ideal for minimal-gate microcontroller designs.

Frequently Asked Questions

How does a stack machine differ from a register-based processor like MIPS or RISC-V? Register-based processors require explicit source and destination registers for every operation (e.g., ADD $t0, $t1, $t2). Stack processors retrieve operands implicitly from the top of the stack (e.g., ADD), making instruction encodings smaller and simplifying compiler backend design.

Can I simulate call stacks and recursive functions? Yes. The software features a dual-stack configuration: an Evaluation Stack for immediate operand manipulation and a separate Return Stack (Call Stack) to handle stack frames, function arguments, and return addresses during nested or recursive calls.

Is this simulator compatible with WebAssembly (Wasm) concept testing? Absolutely. Because WebAssembly operates as a stack-based virtual machine, this simulator serves as an ideal introductory tool for learning how Wasm instructions manipulate data types, locals, and control blocks.