How does the smartphone CPU Work?
In this post, we will give you every Single Detail, About the Topic – How does the smartphone CPU Work?, Your smartphone has a variety of components that can do dozens of different things and the brain at the center of all these components and functions is the system on a chip or soc for short when you read this post such as this one phone a friend across the country or navigate through a city using GPS it may seem like magic or alien tech but in reality, these feats of technology are all performed inside this soc which is designed and manufactured through the hard work of countless scientists and engineers in this episode we’re going to explore each section of this soc and then piece together the processes the system on a chip goes through when you do something is routine is snap a photo and post it online.
These chips are unfathomably complex as there are between 5 and 10 billion transistors that make up the soc and they all need to fit into an area the size of a penny this is a complex topic and there are many avenues that we could explore but in order not to overload your brain with detail, we’ve decided to focus on the following aspects
first, we’ll start with a few notes and caveats and then we’ll dive into the layout and key sections of the system on a chip.
next, we’ll explore how data flows through the SOC using the example of These Questions.
Q: What happens when you take a picture then we’ll look at some of the complexity inside the central processing unit or CPU block of the SOC?
and stick around until the end where we’ll discuss
Q: How scientists and engineers design and manufacture these microchips and we’ll explore what a nanoscopic view of the soc would actually look like compared to this visualization?
So for this Amazing Article grab, a snack sits down, and maybe take some notes if you feel like it because this is going to be one very thorough and incredibly detailed Article.
This microchip is actually composed of two key parts on top is the dram or the dynamic random access memory which is the working memory of your smartphone and on the bottom is the soc the brains of your smartphone FYI the long-term memory where all your music apps files and the operating system are saved ( see Image ), In the flash storage we have a separate episode on that microchip and you can find it here but in this episode.
We’re going to focus on the SOC ( SYSTEM ON A CHIP )
This setup is called a package on package microchip or pop technically this is the microchip and the separate layers of the dram and so care each called a die.
The word chip has evolved to mean a variety of things so while all of these rectangular components are microchips or chips both the dram and system on a chip are also called chips.
Even though they’re just half of the overall package on package microchip moving on we may make comparisons or analogies between smartphones and humans for example we called the soc.
The brain of the camera can be considered similar to a human eye however these are two very very different systems and while the analogies may be useful conceptual tools the underpinning principles behind socs and human brains and how they work are entirely different finally the companies that design these socs are incredibly secretive about the specifics of how they work and what the actual designs look like it takes dozens of different companies to design the optimal layout for billions of transistors to perfectly execute the functions of a phone and a separate set of companies to manufacture the billions of chips used by all our phones so in this post we’ll provide you with the best information we can considering the company’s secrecy of intellectual property, as a result, this information will be mixed and woven together from different sources
For example, this is an LG v10 smartphone from 2015 and it uses a Qualcomm snapdragon 808 but due to the limited availability of information on it we’ll have to use images and information from the apple a12 and 813 microchip in the iPhone 10 and iPhone 11, as well as the Qualcomm snapdragon 865 in the Samsung s20 all of these microchips, have different performance metrics and different capabilities but fundamentally they work on similar principle okay with all of these notes covered let’s move on to understand how this system on a chip works.
A human brain has different sections for processing information received by your eyes and ears a different section for speech ones for controlling your taste smell movement balance involuntary functions and so on rather similarly this system on a chip is divided into different functional areas, a graphical representation called a block diagram.
The key areas in the soc are the CPU containing multiple cores the GPU which renders graphics the shared memory cache which is usually around four to eight megabytes of the digital signal processor which interfaces with things like these Features and Functions.
And many other things
The display engine which communicates with the touch screen display the video processor which compresses and decompresses images and video and enables 4k video recording in playback the image signal processor which processes pictures and video taken by the cameras the modem which interfaces with the various wireless networksthe storage controller which saves and loads information from the flash storage microchip the memory controller which connects to the dram microchip located on top of this one, the security enclave which executes encryptionand manages the public and private keys a number of peripheral functions such as clocks temperature sensors debug ports and general purpose inputs and outputs an always-on micro controller unit and finally the network on chip or knock which arbitrates or manages data flow through the soc, the dram and other parts of the phone furthermore some socs may have on board power management circuits that complement the power management performed by separate ships outside the soc additionally some socs such as apples have a neural processing unit or an npu that is specialized circuitry that can execute machine learning algorithms far more efficiently than the cpu both in terms of speed and more importantlypower consumption one confusing detail is the different generations of socs use different marketing names and mix multiple functions into different functional blocks.
for example, here’s the block diagram of the snapdragon 808 versus the diagram for the snapdragon 865and here’s the block diagram for apple’s a12 chip each company’s marketing team may decide to provide differing block diagrams to try to impress the consumers which at times can certainly be confusing let’s move on and explore a real-life example of this Question.
Q: How data moves around your smartphone when you take a picture?
Continue in the Next Part – click here