What is a System on Chip (SoC) - And Why Can a Single Chip Contain an Entire World?

In the previous post, we asked: What exactly is a chip?

We understood that it’s a physical component containing computing units and electrical circuits.

Now let’s take one step forward - to one of the most important concepts in the hardware world:

SoC - System on Chip Or: an entire system on a single chip.

Why Do We Even Need a “System on Chip”?

In the past, computers were built from many separate components:

• Processor on one board
• Memory on another board
• Communication units elsewhere
• Separate circuits for each function

Everything was large, heavy, and inefficient.

With manufacturing advancements, they realized many capabilities could be unified into a single chip. This is where the SoC concept was born.

What Does an SoC Contain?

An SoC is not a “processor,” but a box full of different units, all on a single piece of silicon.

Typically, it includes:

• CPU - The general processor
• GPU - Parallel computing unit
• NPU / AI accelerator
• Small internal memories (Cache, SRAM)
• Controllers (for cameras, USB, communication, etc.)
• Video processing modules
• Communication buses (Buses / Fabric)
• Power management system

All of this - inside a single piece of silicon.

Why Is This Important?

Because an SoC enables:

• High performance (everything is physically close, therefore faster)
• Low power consumption
• Small size
• High efficiency
• Precise integration for a specific application

This is why every modern phone is based on an SoC.

An Example That Illustrates the Concept

Imagine you’re buying a kitchen:

In the past you would buy:

• Oven
• Stove
• Mixer
• Refrigerator
• Dishwasher

All standing separately.

SoC is like a kitchen where everything is already built into one well-designed unit. More compact, more efficient, fewer unnecessary connections.

SoC ≠ “Processor” - And It Doesn’t Replace Software

This is an important point:

• CPU is just one component inside the SoC
• GPU is another component
• NPU is yet another component

In other words, an SoC is a package that contains several types of computing units plus many supporting components.

Software still runs on this hardware and utilizes its capabilities.

How Is an SoC Built Inside?

Very simply:

Computing Units

CPU / GPU / NPU - these are “the workers”.

Internal Communication Bus (Bus / Fabric)

The way each component talks to the other.

Memories

Each unit needs fast access to data.

I/O Controllers

To communicate with camera, screen, network, etc.

Clock and Power Management

Who works and how, and at what speed.

Why Develop an SoC?

To tailor a chip for a specific task:

• Phone
• Car
• Robot
• Security camera
• AI accelerator
• Medical device
• Communication equipment

Each requires a different combination of units, performance, and power consumption.

Summary

An SoC is:

• Not a single processor
• Not a computing unit
• But an entire system that integrates many capabilities into one chip.

It enables powerful, compact, and economical technology - which is why it has become the global standard.

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In the next post, we’ll understand the fundamental difference between hardware and software - and how you actually “write” hardware and what RTL is.