Learn: Von Neumann Architecture - The Stored Program Concept

Welcome!You've already learned about the CPU, the fetch-decode-execute cycle, and the role of registers. Building on that, today we’ll explore the Von Neumann Architecture, a foundational concept in computer science.

What is the Von Neumann Architecture?The Von Neumann Architecture is a model used in most modern computers. It is based on the idea of a shared memory system where both program instructions and data are stored together in the same memory.This allows the CPU to fetch instructions and data from one place, making it simpler and efficient for general-purpose computing.

The Stored Program ConceptThe Stored Program Concept means that instructions and data are stored together in memory. This allows a computer to change its behaviour by simply loading a different program, without needing to change the hardware.It is this idea that makes modern computers versatile and able to run multiple applications.

Key Components of the Von Neumann ArchitectureThe Von Neumann Architecture includes several important components. Let’s break them down:

Memory Address Register (MAR) and Memory Data Register (MDR)The Memory Address Register (MAR) holds the address of the memory location the CPU wants to access (either to read or write).The Memory Data Register (MDR) temporarily holds the data being transferred to or from memory. Together, they ensure smooth data flow between the CPU and memory.

Program Counter (PC) and AccumulatorThe Program Counter (PC) keeps track of the memory address of the next instruction to be executed. It increments after each instruction is fetched.The Accumulator is a register that stores the result of calculations or operations performed by the ALU (Arithmetic Logic Unit).

How Does the Stored Program Concept Work?In a Von Neumann system, the CPU fetches instructions and data from memory using the MAR and MDR. The Program Counter ensures the CPU knows which instruction to fetch next.This process repeats, allowing the computer to execute a sequence of instructions stored in memory.

Review Time!Well done! You've learned about the Von Neumann Architecture, the Stored Program Concept, and the key registers. Let’s test your understanding.