VON NEUMANN ARCHITECHTURE

 This architecture was named after an American-Hungarian mathematician , a computer engineer, a physicist in 1945.

His architecture is based on stored-program computers.

Now, what are stored-program computers?

There are two main categories of computers, fixed program computers which are non-programmable computers, which means it can’t be instructed to do a specific task.

For example, ac remote, calculators, etc.

And another type is stored-program computers. These, on the contrary, is programmable and can be instructed to do different tasks, for example is our personal computer at home.

In this architecture, the processor and the memory are connected to one bus. This architecture also insists on storing the program and the data n the same storage location. This limits processing one program at a time, and you cannot run a program that will fetch the required data from the storage location due to a single bus.

The main structure of von Neumann architecture comprises of

1.      Central processing unit

a.       Registers

b.      Program counter

c.      ALU arithmetic logic unit ( used to perform logical operations)

d.      Control unit

2.     Main memory unit

3.       i/o system, input or output system

4.      Buses

 Control unit-

It controls the other parts of the CPU and instructs them on how to operate by providing a timing signal and control signal. The timing signal basically deals with the time of execution of instructions, i.e., it maintains the order of the instructions. Each sequence of instructions leads to different outputs, for example, if you take the instructions for having safer sex, i.e., using a condom, which is to wear before fornication takes place, but if a couple wears that later after coitus, then the result will be different, so the sequence of instructions matters. Else expect unexpected output. On the other hand, a control signal is used to control the registers inside the CPU. 

Registers -

It is a high-speed temporary storage part of the CPU. There are several types of register 

MAR - memory address register

PC- program counter

AC - accumulator

MDR- memory data register

CIR- current instruction register

IBR- instruction buffer register

Input and output unit- 

These are required to give instructions to the computer by the user, and it can be done by devices like keyboard, mouse, lightpen, etc. And output devices are where you see the result like the monitor.

Buses- 

Buses connect all the essential components together to make the system work. They transmit data from one end to another, and these are done by three main busses, namely, the address bus, the control bus, and the data bus. 

Memory-

Apart from registers, there are two kinds of memory, primary and secondary memory. Primary memory is often referred to as  RAM random access memory, and secondary memory is the hard disk or solid-state drive commonly known as SSD. The purpose of memory is no brainer, but still, for the sake of writing, it stores data.