Intel motherboard USB 3.0 XHCI controller port configuration, 3.0 xhci

Intel motherboard USB 3.0 XHCI controller port configuration, 3.0 xhci

Generally, Intel has two EHCI and one XHCI on the motherboard that supports USB 3.0 host controllers. This type of motherboard generally has 14 ports, and port 0-3 is shared by EHCI and XHCI, that is, port 0-3 has four switches, and the control registers of these four switches are located in the xhci pci (PCI-E) configuration space, the four switches on the PC are configured in the BIOS. Because many boards are not enabled by default, after you buy a computer, although the computer has a blue USB port, however, if you want to connect your blue USB port to a speeding device, make sure that your motherboard is integrated with the XHCI controller, the XHCI port routing function is enabled in the BIOS, as shown in figure 1.

In Linux, EHCI and XHCI port 0-3 can be switched in the kernel. For code, see the usb_enable_xhci_ports () and usb_disable_xhci_ports () functions in the pci-quirks.c.

Intel also provides a port Switch Driver in Windows. The Driver names are iusb3hcs. sys and iusb3hcs. inf (Intel USB 3.0 Host Controller Switch Driver ).

Figure 1

As shown in figure 2 of the XHCI controller's roothub configuration, the XHCI controller actually has two roothub instances, one of which is roothub 2.0 and the other is roothub 3.0. Finally, the computer manufacturers decided to export several USB 2.0 and USB 3.0 ports.

Because of this XHCI feature, in the Linux kernel, if XHCI controller is found on the PCI (PCI-E) bus, the driver registers two roothub controllers to the USB Core subsystem, one of which is roothub 2.0, one is the roothub 3.0. For code, see the xhci_pci_probe () function in the xhci-pci.c. This code was written by an Intel girl named Sarah Sharp, a super NB.

Figure 2

The USB controller is 20 and the port is 11. Why?

What is USB 2.0?

At present, USB devices have been widely used, but the USB interface is widely used. The transmission speed is only 12 Mbps. For example, it takes four minutes to scan a 40 m image with a USB scanner. This speed makes users feel very inconvenient. If you want to scan several images, you have to wait patiently.

Users' needs are the driving force for technological development, and manufacturers also recognize this bottleneck. At this time, COMPAQ, Hewlett Packard, Intel, Lucent, Microsoft, NEC, and PHILIPS jointly developed the USB 2.0 interface standard. USB 2.0 increases the data transmission speed between devices to 480 Mbps, about 40 times faster than the USB 1.1 Standard, the biggest benefit of speed improvement for users is that users can use more efficient external devices, and peripheral devices with multiple speeds can be connected to USB 2.0 lines, there is no need to worry about the bottleneck effect during data transmission.

Therefore, if you use a USB 2.0 scanner, it will be totally different. It takes about half a minute to scan a 40 m image, and the efficiency will be greatly improved.

In addition, USB 1.1 can use cables of the same specifications as in the original USB definition, and the connector specifications are identical. USB features are also maintained at high speed, USB 2.0 is not compatible with USB 1. any conflict occurs when X devices are used together.

In addition, in terms of software, Windows fully supports USB 1.x. for USB 2.0, the system can recognize and work properly, but USB 2.0 cannot give full play to its performance advantages, after the system detects a USB 2.0 device, it will prompt you that your USB device needs to be optimized. Currently, WINDOWS 2.0 is not fully supported, while LINUX, MACOS, and BEOS have all come to the forefront, and related software support or system packages are available. However, it is certain that Windows will catch up very quickly when a product with the USB 2.0 specification appears. Windows xp now fully supports USB 2.0 devices, but Microsoft will soon launch a USB 2.0 patch when the system motherboard is 1 but supports USB 2.0. Therefore, we can say that, with support from INTEL and Microsoft, the USB2.0 standard has become an important trend for the next generation of peripheral device interfaces.
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Appendix:
The current USB 2.0 has two speed standards. One is USB 2.0 full, and the transmission speed is 12 Mb/s, this is the same as the original USB 1.1/1.0 specification (the original USB 2.0 is used for some materials). The other is the USB 480 high, and the transmission speed is Mb/s, when marking USB specifications, some irresponsible manufacturers often make the USB 2.0 full specification a simple landmark as USB 2.0, which leads consumers to misleading purchase, therefore, when buying a USB 2.0 interface device, you should be aware of whether the USB 2.0 Full or USB 2.0 High standard is used.

How to enable Asus P8Z77-M PRO motherboard front-end USB 30 Port

Oh, install the driver... plug in the motherboard on the 3.0 line in front of the chassis.