Shulou(Shulou.com)11/24 Report--

Photo Source: unsplash, it doesn't matter whether the Tower of Babel is built or not, can't we even build the Tower of Babel with a charging wire?

"which one of you has the charging cord for your xx phone?" Whenever this request rings in our ears, it reminds us that there are a variety of uncommon mobile phone charging lines on the market. There are three main interfaces at the end of the charging line connected to the phone, Android, iPhone and old phone, whose names are USB Type-C (or USB-C), lightning and Micro-USB. At the end of the charging head, the interface is divided into USB-C and "traditional USB". The official name of "traditional USB" is USB Type-A, which is square in shape and cannot be inserted forward or backward.

From left to right are Micro-USB, Lightning, USB-C and USB Type-A. Picture source: unsplash if you need to use a projection screen for a meeting, you may have to use a special video interface again. The video interface on the projector is mainly divided into HDMI and the old-fashioned VGA; on the computer monitor, there is also a video signal interface called DP (DisplayPort).

From left to right are HDMI, VGA and DP, all of which transmit video signals. Among them, VGA is too old to transmit sound. Photo Source: you may have fainted when wikipedia saw this. In fact, as an ordinary person, it is normal not to know this. After all, not everyone is the "tech geek" who spends every day in electronics, and not everyone cares about these innocuous issues most of the time.

In September this year, the European Commission announced a new legislative proposal, hoping to unify the charging interface types of portable electronic devices such as smartphones and tablets within two years, and the USB-C interface will become the common standard for electronic devices in the European Union. In October, Greg Joswiak, Apple's vice president of global marketing, said in an interview that Apple would "have to" use the USB-C interface on the iPhone.

It seems that in the future, as long as the old-fashioned Micro USB is slowly decommissioned, the mobile phone charging interface will be unified into USB-C. And USB-C also has video transmission capability, can we throw away other data cables and replace them all with USB-C?

It may not be too good, at least one USB-C cable should not work. At this stage, when all interfaces are unified into USB-C, we may face an unexpected problem-the standard of USB interface is too messy!

Universal interface when the USB interface was born, no one would associate it with "chaos". This kind of interface called Universal Serial bus (Universal Serial Bus) is born to be unified. Before the emergence of USB, a series of computer peripherals, such as mouse and keyboard, printer, camera and so on, used different interface standards when connecting to computers, and people needed a unified interface to change the dilemma of "dancing with demons and demons".

Connect the PS / 2 interface of the keyboard and mouse. Photo: in Jud McCranie / Wikipedia1995, seven companies, including IBM, Intel and Microsoft, jointly established the USB standard and established the USB developer Forum (USB Implementers Forum,USB-IF) in order to simplify the process of connecting peripherals to personal computers. This kind of interface can transmit signal as well as power. In the original USB 1.0 standard, there were only two forms of USB interface, the Type-A that connects the computer and the Type-B that connects the peripherals of the computer. At that time, the USB standard was not perfect enough to be vigorously promoted in the market. Until the USB 1.1 standard came out in 1998, the USB standard was gradually popularized.

In April 2000, the USB 2.0 standard was released. This standard not only increases the data transmission speed of USB from 12 Mbps to 480 Mbps, but also introduces a Mini-USB interface to reduce the size of the USB interface for portable devices. In 2007, they introduced a smaller Micro-USB interface, which is only 1.8mm thick, in response to the trend that electronic devices are getting thinner and more portable.

By 2008, there were 6 billion USB interfaces around the world. Except that the data bandwidth required by the monitor is too large, USB seems to be able to connect all computer peripherals. During the past 8 years, personal computers have also developed rapidly, and the speed of USB interface 480Mbps is gradually falling short of its ambition. As a result, the USB 3.0 standard appeared, which added several additional pins inside the USB interface to transfer data, thus increasing the interface speed of USB to 5 Gbps. The standard also adjusts the color of the plastic sheet in the interface from the original white to blue (color number Pantone 300C) to distinguish it from the original USB 2.0 standard.

The newly added pins in the USB 3.0 standard are relatively low in the interface, and if they are inserted slowly into the USB interface, it may result in poor contact of the newly added pins, and the system can only recognize the pins of the original USB 2.0-so when the insertion speed of USB 3.0 is slow, it is actually USB 2.0.

As for the Micro-USB interface, it is already very small, and the 3.0 standard can only lengthen the entire interface horizontally, adding additional pins to the interface next to it. So the Micro-USB interface on the old phone is actually USB 2.0.

So far, everything seems to be fine, and the USB interface did its job well-- until the USB 3.1 standard in 2013.

Chaotic standards in 2013, the USB 3.1 standard was released, raising the maximum speed of USB to 10 Gbps. The standard renamed the highest USB standard to USB 3.1 Gen 2, and changed the original USB 3.0 interface name to USB 3.1 Gen 1. The plastic sheet in the USB 3.1 Gen 2 interface has been changed from blue to light blue to make a distinction. Whether it's naming or as a color logo for distinction, USB-IF doesn't seem to want consumers to distinguish between the two standards.

In 2014, the USB-C interface standard came out. USB-C no longer distinguishes the front and back of the interface, and is small enough to be used on portable devices, which is the most common interface on smartphones today. However, USB-C is only a physical interface, and the USB standard used on different USB-C interfaces is not fixed, which lays the groundwork for the later chaos of "the same interface, different functions."

In 2017, the USB interface standard was upgraded to USB 3.2, and the latest version of the USB interface can transmit data at 20 Gbps-- which is a good thing, but the naming standard in USB 3.2 is eye-popping:

Rename USB 3.1 Gen 1 (i.e. USB 3.0) to USB 3.2 Gen 1 with a maximum speed of 5 Gbps

Renamed USB 3.1 Gen 2 to USB 3.2 Gen 2, with a maximum rate of 10 Gbps, and added USB-C support for this mode

The newly added transfer mode is called USB 3.2 Gen 2 × 2, with a maximum rate of 20 Gbps. This mode only supports USB-C and does not support traditional USB Type-An interfaces.

Photo Source: GravityCore / Wikipedia this is not over, maybe the engineers who set the USB standard feel that most people do not understand the amazing naming standard of USB, and they have added more "popular" names to the different transmission modes of USB:

USB 1.0 (1.5 Mbps) is named Low Speed

USB 1.0 (12 Mbps) is named Full Speed

USB 2.0 (480 Mbps) is called High Speed

USB 3.2 Gen 1 (5 Gbps, formerly known as USB 3.1 Gen 1, formerly known as USB 3.0) named SuperSpeed

USB 3.2 Gen 2 (10 Gbps, formerly known as USB 3.1 Gen 2) is called SuperSpeed+

USB 3.2 Gen 2 × 2 (20 Gbps) is also called SuperSpeed+.

What is all this stuff?

Although the name of the USB interface is very confusing, its interface speed has really improved in recent years. USB-IF has a plan to let USB transmit video signals, and they plan to integrate the DisplayPort interface (DP interface) into USB-C. Let the USB data line really realize one line to transmit all the signals.

But USB-C is only a physical interface, and it is not certain what kind of signal transmission protocol is running on it. In addition to the initial addition of DP, USB-C can also transmit signals in MHL, Thunderbolt (also translated as lightning, which itself can transmit DP signals), HDMI and VirtualLink. What's more, there are several versions of each protocol that can be transmitted over USB-C, each of which is more or less different:

DP has DP 1.2, DP 1.4 and DP 2.0 (now DP 2.0 has been renamed DP 2.1)

MHL has MHL 1.0, MHL 2.0, MHL 3.0 and superMHL 1.0

Leili has Leili 3 and Leili 4 (data bandwidth is 40 Gbps)

HDMI only has HDMI 1.4b (the HDMI interface itself is also very confusing, if you want to explain it clearly, you may need to write another article)

VirtualLink also has only VirtualLink 1.0.

Moreover, USB-C cables do not necessarily support all of these protocols, and computer peripherals support different standards.

On September 3, 2019, USB-IF published the USB4 standard. The USB4 interface is developed based on Leili protocol, the data bandwidth is 40 Gbps, and only USB-C interface can be used. But the naming of USB 2.0 and USB 3.2 has not changed, and the confusion of USB culminates at this time. This chaotic interface naming standard, not to mention enthusiasts, even Intel internal experts can not remember its name.

When tech blogger Linus Sebastian was invited to visit the interior of the Intel fab, he found that even inside the fab, no one seemed to remember the name of the USB interface. Photo Source: LinusTechTips belated simplification on October 18 this year, USB-IF released version 2.0 of USB4, which allows the USB interface to transmit data at a bandwidth of 80 Gbps. USB-IF seems to have found some "minor" problems with the naming of the USB interface this time, and finally simplified the naming of USB.

The new USB interface has only one physical interface, USB-C, and is named after the cable transmission bandwidth:

USB 3.2 Gen 1 renamed USB 5Gbps, bandwidth 5Gbps

USB 3.2 Gen 2 renamed USB 10Gbps, bandwidth 10Gbps

USB 3.2 Gen 2 × 2 renamed to USB 20Gbps, bandwidth 20Gbps

The original USB4 was renamed USB 40Gbps, bandwidth 40Gbps

The new standard is called USB 80Gbps, bandwidth 80Gbps.

As for the previous USB 2.0 and USB 1.0, USB Murif thinks that these two interfaces are too old and their names are not suitable for modification. In addition to the data bandwidth, the USB interface must also clearly mark the power it can transmit-and only have 60W and 240W gears.

Finally, the naming of USB is no longer confusing. Does that mean that all I have to do now is to take a USB 240W / 80Gbps cable and go first-line all over the world?

Unfortunately, no. Because in addition to the standard USB-C interface specification published by USB-IF, some manufacturers will modify the USB-C interface in private. For example, in order to increase the charging power of mobile phones, some mobile phone manufacturers will change the definition of internal pins in the USB-C interface. When charging using the general USB interface, these phones may lose their fast charging function.

Moreover, the USB cable with high power and high transmission rate has another problem: expensive. When the cable transmission signal bandwidth increases, the cable manufacturing requirements will increase, the price of USB 40Gbps cable is not cheap, the cost of a data line of more than 1 meter can reach several hundred yuan. Let alone USB 80Gbps, which is not yet on the market. And these high-specification cables are thick and hard, and their portability is poor.

USB unifies all interfaces, which is a beautiful vision, but it also brings an unprecedented problem-the same interface, different functions. Pull out a USB-C data cable that runs on Leili 4, which was launched only 2 years ago, or USB 2.0 (or High Speed) more than 20 years ago. The internal structure of different USB-C cables may be different, but their appearance is almost the same.

So, even if we unify the shape of all the computer peripheral interfaces into USB-C, the Babel Tower of the computer interface may not really be built.

But at least it is much better than that the physical shape of the interface is not uniform and cannot be connected at all.

Reference link:

Https://www.usb.org/pressroom/usb-press-releases

Https://en.wikipedia.org/wiki/USB

Https://arstechnica.com/gadgets/2022/10/all-displayport-2-0-products-are-now-displayport-2-1-vesa-says/

Https://www.macrumors.com/2022/10/25/greg-joswiak-usb-c-iphone/

Https://mp.weixin.qq.com/s?__biz=MzA5NDkzNjIwMg==&mid=2651726152&idx=1&sn=28a4eeba21f9dff66b3d5e3c2c2a3b42&chksm=8bbd8cadbcca05bbe2c8ba2040c4f08b0ccbb34490831614a66fb356c0359735bc5ce99a6912&token=1433179235&lang=zh_CN#rd

Https://www.bilibili.com/video/BV1gg41187XR

This article comes from the official account of Wechat: global Science (ID:huanqiukexue). Article: Wang Yu, revision: chestnut

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