Motherboard: USB

USB is the abbreviation of Universal Serial Bus in English, which means "Universal Serial Bus" in Chinese. It is not a new bus standard, but an interface technology applied in the PC field. USB was jointly proposed by Intel, Compaq, IBM, Microsoft and other companies at the end of 1994. However, it has not been widely used until recently. After the USB V0.7 version was released on November 11, 1994, the USB version has experienced many years of development, and now it has developed into the 2.0 version, becoming the standard expansion interface in the current computer. At present, USB1.1 and USB2.0 are mainly used in the motherboard, and all USB versions are compatible. USB uses a 4-pin plug as the standard plug. It can connect all peripherals in the form of daisy chain, and can connect up to 127 peripherals without losing bandwidth. USB requires the support of host hardware, operating system and peripherals to work. The current motherboard generally adopts a control chipset that supports USB function. The motherboard is also equipped with a USB interface socket. In addition to the backplane socket, the motherboard also reserves a USB pin, It can be connected to the front of the chassis as a front USB interface to facilitate use (note that when wiring, carefully read the motherboard manual and connect according to the diagram, and never connect the wrong device to damage the device). Moreover, the USB interface can also realize the interconnection of two computers through a special USB cable, and can expand more interfaces through the Hub. USB has the advantages of fast transmission speed (USB1.1 is 12Mbps, USB2.0 is 480Mbps, USB3.0 is 5 Gbps), convenient use, hot plug support, flexible connection, independent power supply, etc. It can connect mouse, keyboard, printer, scanner, camera, flash disk, MP3 machine, mobile phone, digital camera, mobile hard disk, external optical floppy drive, USB network card ADSL Modem, Cable Modem, etc., almost all external devices.

USB is an external bus standard used to regulate the connection and communication between computers and external devices. The USB interface supports the plug and play and hot plug functions of the device.

USB interface can be used to connect up to 127 kinds of peripherals, such as mouse, modem and keyboard. Since its introduction in 1996, USB has successfully replaced serial port and parallel port, and has become one of the necessary interfaces for personal computers and a large number of intelligent devices.  
USB version:

The first generation: The maximum transfer rate of USB 1.0/1.1 is 12Mbps. Launched in 1996.  
Second generation: The maximum transfer rate of USB 2.0 is up to 480Mbps. USB 1.0/1.1 and USB 2.0 interfaces are mutually compatible.
Third generation: USB 3.0 maximum transfer rate 5Gbps, downward compatible with USB 1.0/1.1/2.0

Front USB interface

The front USB interface is a USB expansion interface located on the front panel of the chassis. At present, there are more and more external devices using USB interface, such as mobile hard disk, flash disk, digital camera, etc., but it is obviously inconvenient to drill behind the chassis to use the USB interface on the motherboard every time when using these devices (especially the frequently used mobile storage devices). The front USB interface provides users with good usability in this respect. At present, the front USB interface has almost become the standard configuration of the chassis, and the chassis without the front USB interface is very rare.
The front USB interface can only be used if it is connected to the corresponding front USB pin on the motherboard (generally 8 pin, 9 pin or 10 pin, two USB pairs, and each USB uses 4 pin to transmit signal and power supply) using the USB cable attached to the chassis. When connecting the front USB interface, be sure to carefully read the relevant contents in the motherboard manual and chassis manual in advance, and never connect the wires incorrectly, or the USB device or motherboard will be damaged.
In addition, when using the front USB interface, pay attention to the problem of insufficient power supply of the front USB interface. When using a USB device that consumes a lot of power, use an external power supply or directly use the USB interface on the motherboard at the back of the chassis to prevent the USB device from being unable to use or damaged.

Different interfaces and data cables of USB

With the popularization of various digital devices, especially MP3 and digital cameras, there are more USB devices around us. However, although these devices all use USB interfaces, the data lines of these devices are not identical. These data lines are the same at one end of the PC, but when connecting to the device end, different interfaces are usually used for volume considerations.

● USB A-type male port
  

Common Mini B 5Pin interface:

This interface can be said to be the most common one at present. Because of its excellent anti misplug performance and small size, it is gaining more and more manufacturers' favor. Now this interface is widely used in card readers, MP3 players, digital cameras and mobile hard disks.

Common Mini B 4Pin interface:

● Mini B 4Pin
  

This interface is commonly used in digital products of the following brands: Olympus's C series and E series, Kodak's most digital cameras, Samsung's MP3 products (such as Yepp), SONY's DSC series, Compaq's IPAQ series

Another form of Mini B 4Pin is Mini B 4Pin Flat. As the name implies, this interface is more flat than the Mini B 4Pin and is widely used in devices.

● MINI B type 8Pin
 

● Mini B 8Pin Round
 

Compared with the previous ordinary type, this type of interface changes the original D-type connector into a round connector, and a bulge is designed to prevent accidental insertion on one side.

This connector can be seen in some Nikon digital cameras, and CoolPix series is more common. Although Nikon has always insisted on using this interface, some newer models, such as the D100 and CP2000, also use the most popular Mini B 5Pin interface.

This interface is also a common interface. For example, we are familiar with iRiver's famous MP3 series, among which the 180TC, known as the "Iron Triangle", and many other products in this series use this interface. The application range of this interface is also wide, but after the iRiver has completely replaced the 3XX series with the Mini B 5Pin interface, this specification is obviously less eye-catching than the Mini B 5Pin.

Introduction to USB 3.0

Intel Corporation (Intel) and the industry's leading companies have jointly formed a USB 3.0 promotion group to develop ultra efficient USB interconnection technology that is 10 times faster than today. This technology is jointly developed by Intel, HP, NEC, NXP Semiconductor, Texas Instruments and other companies. Its application fields include fast synchronous real-time transmission of personal computers, consumer and mobile products. With the growing popularity of digital media and the increasing size of the transferred files - even more than 25GB - fast synchronous real-time transmission has become a necessary performance requirement.  
USB 3.0 has backward compatible standards, and combines the ease of use and plug and play functions of traditional USB technology. The goal of this technology is to launch products that are 10 times faster than the current connection level, and adopt the same architecture as wired USB. In addition to optimizing the USB 3.0 specification to achieve lower energy consumption and higher protocol efficiency, USB 3.0 ports and cables can achieve backward compatibility and support future optical fiber transmission.

USB 3.0 standard officially completed and released

The USB 3.0 Promoter Group, which is composed of Intel, Microsoft, HP, Texas Instruments, NEC, ST-NXP and other industry giants, today announced that the new generation USB 3.0 standard that the organization is responsible for formulating has been officially completed and publicly released. The new specification provides 10 times the transmission speed of USB 2.0 and higher energy efficiency, which can be widely used in PC peripherals and consumer electronics.
The developed USB 3.0 standard has been handed over to the management organization USB Implementers Forum (USB-IF for short) of the specification. The organization will work with hardware manufacturers to jointly develop new hardware that supports the USB 3.0 standard. However, the actual product launch will take some time.
 

The first version of USB 1.0 appeared in 1996, with a speed of only 1.5Mb/s; Two years later, it was upgraded to USB 1.1, and the speed was greatly improved to 12Mb/s. So far, this standard interface can still be seen on some old devices; In April 2000, USB 2.0, which is widely used at present, was launched, with a speed of 480Mb/s, 40 times that of USB 1.1; Now, eight months later, the speed of USB 2.0 has long been unable to meet the application needs, and USB 3.0 has emerged at the historic moment. The maximum transmission bandwidth is up to 5.0Gb/s, that is, 625MB/s. At the same time, it is backward compatible when using the A-type interface.
The IEEE organization also recently approved the new specification IEEE1394-2008, but the transmission speed of the new version of FireWire is only 3.2Gb/s, which is a little more than 60% of USB 3.0. No wonder Apple and other industry manufacturers have generally lost interest in this technology.
USB 2.0 is based on half duplex two-wire bus and can only provide one-way data stream transmission, while USB 3.0 uses dual simplex four wire differential signal line, so it supports two-way concurrent data stream transmission, which is also the key reason for the rapid growth of the new specification speed.
In addition, USB 3.0 also introduces a new power management mechanism, which supports standby, sleep, pause and other states.
Tektronix, a big manufacturer of measuring instruments, announced the first test tool for USB 3.0 last month, which can help developers verify the compatibility between the new specification and hardware design.
USB 3.0 will be called "USB SuperSpeed" in actual device applications, conforming to the previous USB 1.1 FullSpeed and USB 2.0 HighSpeed. It is expected that commercial controllers supporting the new specification will be launched in the second half of 2009, and consumer products are expected to be launched in 2010.