How do SSDs Work? | How does your Smartphone store data? | Insanely Complex Nanoscopic Structures!

Summary

视频脚本详细解释了智能手机和固态硬盘（SSD）如何存储数据。通过纳米级视角，揭示了存储单元内部的复杂结构，称为VNAND，它利用电荷陷阱闪存技术存储电子数量来保存每一张照片、信息和文件。视频还探讨了如何将图片的像素转换为二进制数据，并在SSD中以3比特为单位进行存储，展示了如何通过垂直堆叠的存储单元来增加存储容量，并通过复杂的电路布局实现高速数据读写。

Takeaways

• 📱 智能手机和固态硬盘（SSD）能够存储大量数据，如照片、视频、音乐、信息和应用程序，这些数据都存储在非常小的空间内。
• 🔍 通过纳米级的视角，我们可以看到存储数据的结构，称为VNAND，它存在于智能手机和计算机中。
• 🌐 每张图片、每条信息和每一点数据都以电子的形式存储在被称为电荷陷阱闪存（Charge Trap Flash）的存储单元中。
• 🔢 像素的颜色由0到255的三个数字组合定义，每个数字代表红色、绿色或蓝色，每个像素的颜色由24位二进制数表示。
• 💾 电荷陷阱闪存单元通过在电荷陷阱上放置不同数量的电子来存储信息，较新的技术可以存储16个不同的电子水平。
• 🔒 电荷陷阱设计得可以保持电子数十年，这是固态硬盘存储或写入信息的方式。
• 🔄 为了擦除存储单元的内容，所有电子电荷都被强制从电荷陷阱中移除，将其恢复到最低水平。
• 🏗️ 存储单元垂直堆叠形成字符串，这些字符串被复制成页面，页面再复制成行，行再复制成块，形成了复杂的3D结构。
• 🔡 每个页面由32个相邻的存储单元组成，可以同时激活以写入或读取信息。
• 🔄 存储单元的读取和写入通过选择器和控制门进行，类似于交通信号灯，确保一次只能激活一行或一层。
• 🚀 现代的存储芯片设计使用96到136层的堆叠，每页可以存储多达60,000个相邻的存储单元，整个芯片可以每秒读写约500兆字节的数据。

Q & A

智能手机是如何存储数据的？

智能手机使用一种叫做电荷陷阱闪存（Charge Trap Flash）的内存单元来存储数据，每个单元通过在电荷陷阱上放置不同数量的电子来存储信息。

什么是VNAND，它在智能手机存储中扮演什么角色？

VNAND是垂直NAND的缩写，它是一种3D存储技术，通过垂直堆叠存储单元来增加存储密度。在智能手机中，VNAND用于存储大量数据，如照片、视频和应用程序。

为什么智能手机能够存储如此多的信息？

智能手机能够存储大量信息是因为使用了高度复杂的微缩技术，可以在极小的空间内存储数十亿比特的数据。

固态硬盘（SSD）是如何工作的？

固态硬盘使用与智能手机类似的电荷陷阱闪存技术来存储数据。数据以电子的形式存储在记忆单元中，通过改变电子的数量来表示不同的数据位。

一个像素的颜色是如何在智能手机中被表示和存储的？

一个像素的颜色由红、绿、蓝三种颜色的组合来定义，每种颜色由一个0到255之间的数字表示，这些数字在计算机中以8位二进制数（即0和1的序列）来存储。

为什么说电荷陷阱是存储数据的关键？

电荷陷阱是存储数据的关键，因为它能够保持电子（电荷）数十年，这样即使在断电的情况下，信息也能被保存在固态硬盘或智能手机中。

如何理解内存单元中的电子数量与存储数据的关系？

在内存单元中，不同的电子数量代表不同的数据位。例如，很少的电子可能代表011，一些电子可能代表100，而很多电子可能代表000。这些不同的电子数量组合起来可以存储更多的信息。

为什么现代的存储设备能够存储更多的数据？

现代存储设备能够存储更多的数据是因为工程师们开发了更精细的技术来捕捉和测量电荷陷阱上的电子数量，从而每个单元可以存储更多的比特。

在存储设备中，如何组织和访问这些存储单元？

存储单元被组织成字符串、页面、行和块的结构，通过使用控制门和位线选择器，可以精确地访问和操作单个页面或行中的存储单元。

为什么说智能手机和固态硬盘的存储技术是工程学上的奇迹？

智能手机和固态硬盘的存储技术是工程学上的奇迹，因为它们能够在极其有限的空间内存储大量的数据，并且能够快速、可靠地读取和写入这些数据。

Outlines

00:00

📱 智能手机和固态硬盘的数据存储原理

本段介绍了智能手机和固态硬盘（SSD）如何存储大量数据。通过深入探究，我们了解到存储设备内部的复杂结构，特别是VNAND技术，它是存储设备中用于保存数据的关键结构。视频将通过实例讲解如何将图片保存到智能手机或电脑中，解释了像素、颜色和二进制的关系，以及如何将图片转换成二进制数据。此外，还简要介绍了如何通过图像编辑软件查看像素和RGB值。

05:03

🔬 电荷陷阱闪存（Charge Trap Flash）的工作原理

这一段深入解释了电荷陷阱闪存（Charge Trap Flash）的工作原理。每个存储单元通过在电荷陷阱中放置不同数量的电子来存储信息。现代技术允许每个单元存储多达8个不同的电子水平，而新技术甚至可以存储16个不同的水平。这意味着一个单元可以存储3个或更多的比特。此外，还介绍了如何通过垂直堆叠存储单元来增加存储容量，以及如何通过控制门来读写信息。

10:05

🏗️ 存储单元的组织结构和数据读写过程

本段进一步探讨了存储单元的组织方式，包括如何将它们垂直堆叠成字符串、页面、行和块。解释了如何通过位线选择器和控制门选择器来激活特定的存储单元，以及如何通过页面缓冲区读写信息。此外，还提供了一个实际的存储容量示例，说明了如何通过这种复杂的结构存储一张图片的数据。

15:08

🚀 固态硬盘的复杂布局和读写速度

最后一段总结了固态硬盘的复杂布局，包括多个芯片的堆叠和接口芯片的使用。介绍了固态硬盘的读写速度，以及如何通过复制复杂的存储单元布局来增加存储容量。同时，还提到了视频的后续内容，包括对电荷陷阱闪存、位线和控制门选择器的工作原理以及微芯片制造过程的详细解释。最后，鼓励观众订阅频道并参与评论，分享视频以帮助他人了解这项技术。

Keywords

💡智能手机

智能手机是一种便携式移动设备，具有电话功能和多种其他功能，如上网、拍照、播放音乐等。在视频中，智能手机是数据存储技术的核心载体，展示了如何在其小巧的机身内存储大量信息。

💡固态硬盘(SSD)

固态硬盘是一种数据存储设备，使用闪存技术来存储数据，相较于传统硬盘，它具有更快的读写速度和更好的抗震性。视频中提到固态硬盘内部结构的复杂性，以及它是如何在笔记本电脑或计算机中存储大量数据的。

💡VNAND

VNAND，即垂直NAND，是一种3D NAND闪存技术，通过垂直堆叠存储单元来增加存储密度。视频中解释了VNAND是智能手机和固态硬盘中存储数据的关键结构。

💡电荷陷阱闪存(Charge Trap Flash)

电荷陷阱闪存是一种存储技术，通过在电荷陷阱中存储不同数量的电子来保存数据。视频中提到，每个像素、每条信息都以电子的形式保存在这些存储单元中。

💡像素

像素是构成图像的最小单位，每个像素具有特定的颜色值。视频中解释了像素如何通过红、绿、蓝三种颜色的组合来定义，并且每个像素的颜色值由24位二进制数表示。

💡二进制

二进制是一种数制，只使用0和1两个数字来表示所有数值。视频中提到，计算机使用二进制来表示颜色值，每个颜色值由8位二进制数表示。

💡位(Bits)

位是计算机科学中的信息单位，代表一个二进制数字，即0或1。视频中提到，一张图片由大约293百万位组成，这些位是存储在智能手机或固态硬盘中的数据。

💡存储单元

存储单元是存储设备中用于保存数据的最小物理单位。视频中提到，每个存储单元可以通过不同数量的电子来存储不同的信息级别，从而存储更多的数据。

💡页(Page)

在固态硬盘中，页是一组存储单元的集合，可以一次性读取或写入。视频中解释了页是由32个串联的存储单元组成的，并且是数据读写的基本单位。

💡块(Block)

块是由多个页组成的更大的存储单元集合，在固态硬盘中用于数据的擦除和写入。视频中提到，一个块由6个页组成，并且是数据存储结构中的一个复杂层级。

💡行(Row)和列(Column)

在固态硬盘的数据组织中，行和列是用来描述存储单元的排列方式。视频中提到，行由多个页组成，而列则是由多个行组成的更大的结构。

💡位线(Bitline)

位线是连接存储单元和读取/写入电路的导线，在视频中，位线被比喻为信息高速公路，用于传输存储单元中的电子电荷信息。

💡控制门(Gate)

控制门是用于控制电子流向和读取存储单元中信息的组件。视频中提到，每个存储单元层都有一个控制门，用于激活特定的存储单元。

💡擦除(Erase)

擦除是清除存储单元中的数据的过程。视频中解释了，为了擦除存储单元，所有的电子电荷都被强制移除，将存储单元恢复到初始状态。

Highlights

智能手机和固态硬盘如何存储数据，这是一个令人难以置信的谜题。

一太字节的固态硬盘通常可以在笔记本电脑或电脑中找到。

VNAND结构是智能手机和电脑存储数据的关键。

每个像素的颜色由红、绿、蓝三色的数值组合定义。

每个像素的颜色值由24位二进制数表示。

电荷陷阱闪存（Charge Trap Flash）是计算机长期存储的基本单元。

通过在电荷陷阱上放置不同数量的电子来存储信息。

现代技术可以在单个存储单元中存储多达3位的信息。

电荷陷阱设计用于长期保持电子，这是数据保存的方式。

内存单元垂直堆叠形成VNAND，增加了存储密度。

通过控制门和位线选择器，可以精确读写单个页面的数据。

一个内存块由多个页面组成，每个页面包含32个字符串。

通过复杂的布局，可以在单个芯片中存储大量数据。

最新的设计使用96到136层的堆叠，增加了存储容量。

一个页面可以包含多达60,000个相邻的内存单元。

整个芯片可以每秒读取或写入大约500兆字节的数据。

工程师将这种复杂的布局复制到芯片的另一面，以增加容量。

一个微芯片可以包含8个这样的布局，通过接口芯片进行协调。

视频还提供了额外的注释和评论，以帮助理解。

Transcripts

How do Smartphones Store Data? || How do SSDs Work? By Branch Education

It’s hard to believe that all your photos, videos, music, messages,

and apps can be stored in the palm of your hand,

and to most of us it’s a mystery how so much information

can fit in such a small space.

But it might not seem so surprising when you see

the complexity inside your smartphone,

or the inside of this one terabyte solid state drive

commonly found in laptops or computers.

However as seeing the outside of this memory storage microchip

tells us little about how these smartphones

and solid-state drives can store tens of thousands of photos

and files, let’s explore deeper and zoom in until we get

to a nanoscopic view, and it's here that we can see the structures called

VNAND that hold all the data in your smartphone and computer.

Here is where the real magic happens.

Every picture, message, and bit of information

gets saved as quantities of electrons

inside these memory cells which are called charge trap flash

and, in this episode, we'll learn how smartphone memory and solid-state drives work.

Now, hold on- these insanely small and intricate structures seem very complex,

and yeah- they are- I’m not going to say this marvel of engineering is simple.

But you have to trust me- stick around,

watch closely, maybe watch this video twice,

and by the end of it, this technology will amaze you,

it will blow your mind at least twice over, and yeah, you'll have

a thorough understanding as to how such a small device,

can store weeks of high quality video, tens of thousands of pictures,

or hundreds of thousands of songs in such an itty bitty little space.

So, let’s get started.

We’re going to use a real-life example and

explore how it works when you save a picture to your smartphone or computer.

First, this picture is made up of pixels

and each pixel has a color so let’s zoom in so

that we can see the individual pixels.

The color of every pixel is defined by a combination of 3 numbers,

ranging from 0 to 255, each representing red, green, or blue.

For example, the numbers would be 55-53-55

for this pixel’s color right here,

and then 124-121-119 for this pixel.

Each of these 3 numbers from 0 to 255 is represented

by 8 bits in binary, or eight ones and zeros ya know,

because computers work in binary.

So, 3 colors, red, green and blue, and 8 bits each,

means each pixel takes 24 bits to define its color.

This picture is a grid of colored pixels,

so let’s turn it into a grid of values, kind of like a spreadsheet in excel,

but called an array instead of a spreadsheet.

This array of bits is what your computer cares about and noncoincidentally,

it’s also the information that the camera on my smartphone

recorded when I took the picture.

One quick note: if you want to see the pixels in any picture,

just open it in an image editing program like paint

or 3D paint in this case, and zoom in.

And then if you want to see the red, green and blue

or RGB values, just use the eye dropper, click on a pixel,

and then click on the edit color option.

Right here you can see the 3 values

for red, green, and blue, and the resulting color.

Ok, with that covered, let’s get back to this episode,

first, we’re gonna zoom out to see the full picture,

which is 3024 pixels wide and 4032 pixels tall,

which is a total of around 12 million pixels, or, 12 megapixels-

which relates to the resolution of the 12 megapixel camera on my smartphone.

Next, by doing some multiplication

we calculate that an array of this size,

where each pixel is defined by 24 bits,

or 24 0s or 1s only requires 293 million bits

or a unique set of 293 million 0s or 1s.

That’s a ton of bits, so let’s figure out how your smartphone

or this solid-state drive seamlessly

stores every single one of them.

Ok: so let’s open up that solid state drive again

and zoom into a simplified nanoscopic view

kind of like the one we had earlier.

It's here that we can see the memory cells

that are used in every single one of your smartphones or tablets,

as well as inside the solid-state drive in your computer.

This is the basic unit of a computer’s long term memory storage

and it’s called Charge Trap Flash Memory-

so how does it work?

Well, in each cell we can store information by placing different

levels of electrons onto a charge trap,

which is the key component inside the memory cell.

Older technology could only store two different levels of electrons,

a lot of electrons or very few electrons,

which were used to store a single bit as a 1 or a 0.

However, engineers have been developing more finely tuned capabilities

for trapping and measuring different amounts of electrons

or charges onto the charge trap.

Most memory cells in 2020 can hold 8 different levels,

but newer technology can have 16 different levels of electrons.

This means that a single cell,

instead of holding only one bit as a lot of electrons or no electrons,

can now hold 3 or more bits

but, for this example, let’s stick with 3 bits.

So- in this cell, if we were to have very few electrons on it,

it would be 1-1-1, while some electrons get designated as 1-0-0

and a lot of electrons are 0-0-0

There are 8 different levels for all the various amounts

of electron charges that our charge trap can be set or written to.

The key to the charge trap is that it is specially designed

so that after it gets charged with electrons,

it can hold onto those electrons for decades,

which is how information is saved or written to the solid-state drive.

I mean- it’s called a charge trap for a reason.

It traps electrons, or charges for years on end,

and in order to read the information,

the electron charge level is measured,

and the amount of charge on the charge trap is unchanged.

However, in order to erase the contents of a memory cell,

all the electron charges are forcibly removed

from the charge trap returning it to its lowest level,

which is 1-1-1, and leaving no excess electron charges behind.

Let’s move on and explore how these memory cells are organized

so that we can store more than just 3 bits of information.

After we zoom out a little,

you can see that the memory cells are stacked vertically.

This is where the vertical part in Vertical NAND or VNAND comes from.

This stack of memory cells,

what is technically called a string is composed of 10 charge trap flash cells

layered one top of another.

when information is written to or read from a string,

only one cell can be activated at any given time,

and to do that we use separate control gates

attached to every layer in the string.

It works like this: the bottom control gate first says

“Hey you, charge trap 1 what’s your electron charge level at?”

Then the bottom cell sends that information through

the center of the string up to the information highway at the top,

which is technically called a bitline.

Then the next control gate for the 2nd layer

asks for the charge level in the 2nd cell, and so on,

up the string, each cell sending their

information up to the highway or bitline.

The same kinda sequence happens when charges are being added

to a charge trap which is how information is written to a memory cell.

The main thing is that only one layer in the string

is either written to or read from at any given time.

Let’s move on in complexity, next we duplicate this string 32 times,

and this gets us a page of strings.

Let’s review some terminology:

this a memory cell and this is a string.

And now here we have a page, and we are going to call this entire

page of strings a row. When we duplicate the string,

we also duplicate the bitline 32 times,

however rather than duplicate the control gates,

we are going to have every cell in the same page

share a common control gate.

This makes it such that when information is written

to or read from a row,

an entire page composed of 32 adjacent cells,

all in the same layer, are activated at the same time.

Let’s step up in complexity again:

Next, we duplicate these rows 6 times until we get a block,

but we are going to do it 12 times so we can see 2 blocks.

Okay, so again, here we have a column,

here is a row, this is a layer. And now here is a cell

and here is a string. Next we have a page,

and finally we have a block. We are going to connect the tops

of each string in a column together,

so they all share the same bitline

and our bitline is looking more like a highway now.

In addition, we have to add a control gate that selects between rows,

so that only one row is using the bitline at a time.

These are called bitline selectors.

As discussed these bitlines are like highways,

and the selectors at the top act as traffic lights that

mediate the flow of information

so that only a single row can use the highway,

or is active at a time. Similarly, the control gates attached to each layer

act as traffic lights for the layers.

With bitline selectors along the tops of each row,

and control gate selectors along each layer,

the solid state drive can read from or write to a

single page at any given time.

Additionally, in order to connect to the bitline selectors

and control gate selectors there are wires that drop down from above

and run perpendicular to the bitlines.

So, let’s quickly recap:

8 different levels of electrons are placed on charge traps

in order to store 3 bits of information.

These charge trap flash memory cells

are stacked into strings 10 cells tall,

which are duplicated into pages of 32 strings in a row.

Next, those pages of strings are duplicated

until we have a block 6 rows deep,

and here we are showing 2 blocks.

Doing some quick multiplication we find that there are

3,840 memory cells here

capable of storing a total of 11,520 bits.

With each pixel in our picture requiring 24 bits,

that means that we can store 480 pixels,

or this much of our overall picture.

That means you need about 25 thousand times the size of this layout

to store the contents of this single picture.

Aaand, here’s where we learn about the actual size of a memory chip.

All the principles we have discussed remain the same,

so keep those in mind, it’s just that the size is much more extensive

than we discussed in our example.

It’s hard to pin down exact numbers because

manufacturers are continually improving their designs

and they are very secretive regarding what their designs look like.

But I’ll tell you what I know:

the latest designs utilize not 10 layers as in the example,

but rather somewhere around 96 to 136 layers tall.

Here's a single sheet of paper so you can get

a sense of the of the approximiate height

of these stacks of memory cells.

Now that we understand the height, lets think about the width.

A page is around 30,000 to 60,000 adjacent memory cells wide.

That means there are 30,000 to 60,000 bitlines

in our information superhighway.

Blocks are every 4 to 8 rows

and there are around 4000 to 6000 blocks.

Along the edges are the control gate selectors

and the bitline selectors on the other side.

Together, they comprise what is called a row decoder,

and by using both sets of selectors as traffic lights,

we're able to accesss a single page.

To repeat this, only one page, 45 thousand or so cells wide,

ever uses the bitline to read or write information at any given time

All tens of thousands of bitlines

feed down here to the page buffer

where the information from a single

page is written to or read from.

Let’s transition to see what an overall chip might look like.

Here we have the arrays of 3D memory cells,

the row decoder and the page buffer at the bottom.

Additional peripheral circuitry can be found here for supporting the chip.

In order to fit more capacity, engineers copied this layout onto the other side.

This chip can read or write at a rate of around

500megabytes per second. That means that it can read from or write to

around 63 blocks every single second.

That’s incredibly fast!

Ok, let’s add the last level of complexity.

Engineers like to fit even more stuff

in as small of a space as possible,

so on top of having a massive array of memory cells

in this insanely complex layout,

they decided to copy this chip 8 times.

and stack it into a single microchip.

At the bottom, an additional interface chip is used

to coordinate between the 8 different chips.

And that’s it, that’s all there is in this one microchip

that can found at the center of every

one of your smartphones, tablets, or solid-state drives.

This video covered a lot, and I hope you kept up.

You can always watch this video a second time,

and if you do watch it a second time, we added our notes and commentary

into the English Canada subtitles.

Turn them on by clicking the settings gear over here.

On the contrary the notes that are placed up here

are caveats or footnotes,

but the notes we placed in the English Canada

subtitles include commentary, additional information,

and much more. Let us know what you think of them in the comments

Also, I will be making a follow up set of episodes

that will branch off and explain

how each part works in detail.

In separate episodes we'll cover specifics

as to how the charge trap flash works,

how the bitline and control gate selectors work,

and how these microchips are manufactured.

Also, take a look at our channel page

where we cover other topics such as how touchscreens work,

how PCBs work, or how cameras in your smartphone work.

If you have any questions

or want me to add more branches relating to solid state drives,

tell us in the comments below.

But for now, thanks for watching.

subscribe and hit the bell to get notified

when we post more branch episodes

on how solid-state drives work and other topics.

If you learned something new, share this video with others-

Tweet it, post it to your favorite discussion board,

or share it on social media so others can

learn how this amazing technology works.

Until next time, consider the conceptual simplicity

yet structural complexity in the world around you.