Comparison and difference of EHCI and OHCI

The current project involves USB devices that inevitably dabble in UHCI OHCI EHCI

So what difference do they have? How to differentiate?

What is EHCI? What is OHCI? is the interface of the host controller. From the hardware, the USB device to work, in addition to the peripheral itself, there must be a drum called the USB host controller. In general, a computer has a USB host Co Ntroller, she can control a lot of devices, such as U-disk, such as USB keyboard, such as USB mouse. All peripherals submit their requests to the USB host controller. Then let the USB host controller Unify to dispatch.
There are now generally two types of USB bridge modules, UHCI and OHCI. When deciding to insert the bridge module, you can look at the/proc/pci file to determine: In general, UHCI type of bridge its insert module is UHCI or USB-UHCI (as determined by the kernel version), and for the OHCI type of bridge its insert module is OHCI or USB-OHCI.

UHCI (Universal Host Controller Interface): A hardware instance of Intel's USB 1.1 host controllers (host control) on its own chipset
EHCI (Enhanced Host Controller Interface): standard interface for USB 2.0 host controllers.
OHCI (Open Host controller inferface): A master interface standard not just for USB. Mainly follows the CSR (Configuration Space register) standard. It is the standard that other vendors follow when designing USB host controllers, such as Via, NEC, Ali, including Nvidia, and so on.
The EHCI is a hardware design that satisfies the requirements of the USB host controller (high speed) in the USB 2.0 specification.

Comparison and difference of EHCI and OHCI