Usb hub specification pdf

The only exception to this is when a device has been put into 'suspend' a low power state by the host then the device can signal a 'remote wakeup'. There are three commonly encountered types of USB host controller, each with its own history and characteristics.

Compaq, Microsoft and National Semiconductors cooperated to produce this standard host controller specification for USB 1. It is a more hardware oriented version than UHCI. Low speed and full speed. Intel's more software-oriented version of a controller for USB 1. Requires a license from Intel. When USB 2. An extension to the USB specification has been defined, to allow a device to also become a limited role host. This specification is known as On-The-Go. A later part is planned, to cover this specication in detail.

We have examined the USB specification from the perspective of the user. Next we will look at the electrical side of things, including cables and connectors. Special Offer. Click for more information. Part 1. Part 2.

Part 3. Part 4. Part 5. Part 6. Part 7. Part 1 - Introduction to USB. This series of articles on USB is being actively expanded. If you find the information useful, you may wish to come back to this page in the future to check for newly added parts. We had serial ports, parallel ports, keyboard and mouse connections, joystick ports, midi ports and so on.

And none of these satisfied the basic requirements of plug-and-play. So the USB was developed as a new means to connect a large number of devices to the PC, and eventually to replace the 'legacy' ports. It was designed not to require specific Interrupt or DMA resources, and also to be 'hot-pluggable'. It was important that no special user-knowledge would be required to install a new device, and all devices would be distinguishable from all other devices, such that the correct driver software was always automatically used.

It may be apparent that, to make a system which is so user-friendly is going to mean a lot of work behind the scenes for the developer. Low Speed This was intended for cheap, low data rate devices like mice. Full Speed This was originally specified for all other devices. The reader is expected to be familiar with the current USB specification revisions. Adopters can demonstrate compliance of their product s with the adopters agreement.

This specification describes the registers and data structures used to interface with the USB Type-C connectors on a system. This specification is intended for hardware component designers, system builders, and device driver software developers. In spite of due diligence, there may exist conflicts between this specification and either one or both of the above mentioned specifications. USB 2. On-the-go Supplement to the USB 2. It does not evaluate the functionality of the USB companion controllers.

This document defines an interface to which ASIC and peripheral vendors can develop. Peripheral and IP vendors will be able to develop their designs, insulated from the high-speed, and analog circuitry issues associated with the USB 2.