Processors (CPU)

What is System on a Chip (SoC)? (Explained)

December 18, 2022

In This Article

What is System on a Chip (SoC)?

System on a Chip or a SoC refers to the Integrated Circuit or an IC that is designed to include all, or most of the components of a computer processor on a single die.

Technically, a SoC is that which has the processors, interfaces, memory, controllers, DSPs, GPUs and more on a single chip.

It can be a Programmable System on a Chip or PSoC as well, which has a unique programmable hardware, such as a Field Programmable Gate Array or FPGA.

KEY TAKEAWAYS

The SoCs are used in a variety of devices such as smartphones, tablets, computers, smartwatches, Internet of Things, embedded systems, and others where a microcontroller is used.
The SoCs have everything installed on a single die that a computer needs to perform such as CPU, GPU, RAM and more.
These chips are usually made up of general CPU cores and special-purpose circuits where the former performs the software instructions concurrently and the latter handles other jobs such as rendering images.
The SoCs typically consume much less power and therefore generate much less heat, two of the most significant positive elements that make them usable in smaller devices, especially those that operate on battery.
Repairing a SoC or replacing any specific part on the chip may be very difficult, if not impossible, as all are closely linked on the single chip leaving no other option but to replace the full chip even when only one part fails.

Understanding System on a Chip (SoC)

System on a Chip refers to a set of processing units on one single die that are connected together.

Ideally, it is the SoCs rather than the CPUs alone that make the complex computers of today.

These relatively smaller chips that have everything that a computer needs to perform on a single die are used traditionally in those devices and embedded systems that are used for specific purpose such as:

Smartphones
Tablets
Laptops
Single-board computers such as Raspberry Pi and others.

Several high-performance processors also use SoC design techniques.

Typically, the SoCs are made up of general-purpose as well as special-purpose circuits.

The CPU cores can execute software instructions simultaneously and the specialized circuits such as the GPUs render the images and screen pixels.

These SoCs include a variety of components and follow a design flow that is aimed at developing different aspects such as:

The hardware and software modules – The hardware blocks are designed from pre-practiced hardware elements and the software modules are integrated by the software development environment.
Functional verification – The logic correctness of the SoCs is verified before they are sent to the foundry.
Verifying hardware and software designs – Different technologies such as simulation acceleration, FPGA, emulation and others are used to verify and debug the hardware and software of the SoC designs.
Placing and routing – Before the fabrication process the entire design is to be placed and routed to the IC. During the fabrication process, standard cell, full custom, and FPGA technologies are usually used.

There are lots of advantages offered by the SoC and its design which includes:

Low power consumption
Low heat generation
Low cost
Higher reliability
Relatively small form factor
Higher integration levels
Faster operation
Great and relatively straightforward design
Multiple functions
Useful features
Higher flexibility

However, there are some significant downsides of the SoCs such as:

High fabrication cost
Longer designing process
Limited visibility
Hard to replace or repair a single component that may have failed

Still there are several good reasons to use the SoCs and some of the major ones are:

Its lower power requirements
Lower cost
Increased performance
Smaller physical size

With the kind of benefits offered, the future of the SoCs seems to be very bright and may find the most prominent, if not the only place, in the world of computing.

SoC in VLSI

VLSI or Very Large Scale Integration and SoC design is considered to be the state-of-the-art concept which provides a platform that includes design, circuits, and automation within digital, analog, and mixed-signal systems.

Typically, VLSI-SoC explores the design and optimization of different embedded systems and 5G and 6G communication systems that are typically powered by CMOS or Complementary Metal Oxide-Semiconductor and beyond CMOS technologies.

Typically, the VLSI chip is made by integrating high-level components and gate-level sophistications in the circuits over and above the register, counter, multiplier, Arithmetic Logic Unit or ALU and floating point operation unit.

Typical of the VLSI design life cycle, there are several stages involved in the SOC design which involves IP cores and more such as:

The soft IP core at the RTL design stage is fully customizable
The firm IP core at the DFT and synthesize stage is accurate, optimized and according to the design standards
The hard IP core is to be placed directly on the layout for interconnections

There are different embeds that are included in the SoC for the VLSI design such as:

Several processors
Memory
Various standard source solutions
Logic and analog units

Each of these embeds are to be made in different ways as explained hereunder.

The multi-processor or dual core general-purpose processors need the following:

Speech signal compression
Speed signal coding
Signal decoding
Signal decompression

While embedding the accelerator, the following things are to be kept in mind:

The execution of codes should be accelerated
The floating point coprocessor should accelerate the mathematical operations
The Java accelerator should accelerate Java code execution

While embedding the single-purpose processors, it is needed to make sure that it should be capable of the following:

Dialing, modulating, demodulating, transmitting and receiving
Handling keypad interface and display interface
Creation of message and display
Protocol stack generation
Handling pixel coprocessor and CODEC in the digital camera

While embedding the ASIPs or Application Specific Instruction Set Processors it must be made sure that the processor comes with an instruction set that is designed for particular type of applications on a VLSI chip. This can be any kind of processor such as:

A microcontroller
A DSP
A network, media, or other domain-specific processor

While embedding microcontroller cores, it must be made sure that it belongs to any of the following:

80251 microcontroller
PIC 16F84 microcontroller
PIC 16C76 microcontroller
PIC 16F876 microcontroller
PIC18 microcontroller
Enhancement of ARM9, ARM7, or ARM Cortex M series

While embedding the DSP cores, it should be made sure that it is TMS320Cxx, OMAP1 Tiger SHARC 5600xx, and PNX 1300 or 15002 that should be capable of the following as well:

Image, video, and signals processing
Filtering and noise cancellation
Echo elimination
Compression and encryption

Typically, a SoC in VLSI typically needs to have all of the necessary digital as well as analog circuits, processors and software.

SoC Examples

One of the most common examples of a SoC is Qualcomm, which is the largest provider of smartphone SoCs. The Exynos SoC from the house of Samsung is also a good example just as the Tensor G2 SoC from Google and the Helio range of SoCs from MediaTek.

Some of the most common devices that use SoCs are gaming consoles such as Xbox and Playstation, Raspberry Pi computers, smartphones, tablets, and others.

These devices use different types of SoCs such as:

SoCs that use a microcontroller such as Arduino boards and have the CPU, ROM, RAM, and other ROM and other components
SoCs that use a microprocessor such as Snapdragon 845, the Apple A12 Bionic SoC and Intel’s line of SoC FPGAs and has a CPU only and are used in smartphones, virtual reality headsets, iPhones
SoCs for specific applications, known as ASICs or Application Specific Integrated Circuits, which may or may not have a microcontroller or a microprocessor.

What are the Components of SoC?

In spite of its small size, the SoC of a smartphone typically connects and controls functional components in it such as the CPU, GPU, ISP, DSP and more.

The different components that are typically found on a SoC are as follows:

The Central Processing Unit or CPU – This component runs most of the apps and the codes for the Android OS.
The Graphics Processing Unit or GPU – This component handles all graphics related tasks for 2D and 3D gaming and also helps in visualizing the user interface of an app.
The Image Processing Unit or ISP – This component handles the data from the camera of the phone into video files or images.
The Digital Signal Processor or DSP – This component deals with all mathematically intensive functions other than those handled by the CPU including analysis of gyroscope sensor data and decompression of music files.
The Neural Processing Unit or NPU – This component is typically found in high-end smartphones and helps in expediting the AI and machine learning tasks including segmentation of camera objects and offline voice recognition.
The video encoder and decoder – This component converts video files and formats allowing power efficiency.
The modem components – This component converts WiFi, Bluetooth, LTE, 4G, and 5G wireless signals into data that can be understood by the phone.
The audio Digital to Analog Converter or DAC – This component converts the digital audio signals into analog signals.
The Universal Asynchronous Receiver Transmitter or UART – This component helps in receiving and sending serial data.
Random Access Memory or RAM – This component is the memory of the computer system that stores the program or application processes.
Read Only Memory or ROM – This component holds the operating system and firmware.
Northbridge/Southbridge – These components act as bridges or an interface between the processor and the other components on the SoC. The Southbridge handles I/O functions such as USB and audio.

Does Intel Have a SoC?

Yes, Intel do have and use SoCs in a few specific areas such as their SoC FPGA or the Field Programmable Gate Array ecosystem, which is based on ARM processor architecture, and most of the Intel Next Unit of Computing or NUCs are based on a System on a Chip rather than a chipset as well.

Some of the examples of Intel SoC FPGAs are:

Intel Agilex built on Intel 7 nm and 10 nm SuperFin technology that allows customized acceleration and includes F-Series, I-Series, M-Series, D-Series, and Direct RF-Series SoC FPGAs
Intel Stratix 10 SoC FPGAs that offer high-end performance
Intel Arria 10 and Arria V SoC FPGAs that offers high performance and efficiency in midrange
Intel Cyclone V SoC FPGAs that offer power and cost efficiency

As for the NUCs, there is a large variety of models available and they come with Intel Core i3, i5, i7, or i9 processors of different generations from 5^th the generation to the 13^th generation.

There are also a few NUC models with other Intel processors such as Celeron, Pentium or Atom in them. You will also find a couple of different Legacy Intel NUCs with SoC and Intel Core i3 or i5 processor.

Do Smartphones Have a SoC?

Yes, typically, the smartphones, and even the tablets and wearables, do not use processors as such. Instead, they all use a SoC.

Ideally, it will need a lot of space on the semiconductor die to have all of the necessary hardware components separately installed on it which includes the CPU, GPU, memory, modem and lots more.

Therefore, incorporating all these items and features on a single die will help significantly in keeping the overall footprint of the phones low.

Apart from that, combining the different components of the smartphones required to operate into a single chip not only saves on the space but also on other aspects such as:

Power consumption
Heat generation
Cost.

So, a SoC is used in smartphones. The different components that the SoC connects include:

The display
The camera
The flash storage and lots more.

In short, the SoC acts as the brain of the smartphones and handles everything from the graphics performance to 5G connectivity and from the operating system to detecting the power off button when pressed.

SoC vs CPU

The SoC is a single piece that has all the functional parts on it, and the CPU is just another component on it.
The SoC does not have to rely on other external hardware to perform because it is self sufficient having all the necessary components on it, whereas the CPU has to rely on RAM and other hardware items to function.
A SoC uses shorter wiring in comparison to CPUs.
The SoC is more energy efficient and consumes less power and therefore generates less heat than the CPUs.
Repairing a SoC is quite complicated since it has all the components installed in it, which also makes it quite impossible to replace a single component such as the RAM, CPU or GPU in comparison to an independent CPU.
The functionality of the SoC is much more than the CPU which can only crunch through a program read in from the memory, but a SoC can do all that a device needs to function.
The size of the SoC is a bit larger than the CPU but it still allows using it in smaller devices such as smartphones, tablets and others very easily in comparison to the CPUs.
The SoC has almost all the interfaces on the same chip but a CPU usually does not.
The pin count of the SoC is a trade-off due to the higher density which is why it often uses a gate called pin mux, unlike the CPUs.

Questions & Answers:

Is RAM a Part of SoC?

Yes, RAM or the system memory is a part of a SoC since it is one of the major functional components that make the system work.

Is SoC a Hardware or Software?

A SoC is typically a hardware which contains all the functional units which includes the processor, graphics card, modems, flash storage and the communication subsystem that connects, controls, directs and interfaces between the functional modules.

Is a GPU a SoC?

Typically, the SoCs are much smaller in design and the GPU, just like the CPU, is just another component on this small chip.

Is SoC Analog or Digital?

Typically, a SoC is described as digital because the focus on the design and verification of a system is primarily digital.

However, due to the AMS components, a SoC may be analog, digital, and mixed. Sometimes it may also contain Radio Frequency of RF functions for communications.

Conclusion

As you can see from this article, the System on a Chip is very useful to use in the smaller devices.

It is even considered as the next step next the CPUs and may consume the customary CPUs totally.

Ideally, the fact that Intel Ivy Bridge and AMD Llano CPUs have different parts on the same chip at least points towards it.