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1.1 motivation (Motivation)
Universal Serial Bus (USB) original motivation comes from several considerations, the two most important aspects are:
Easy to use ( as Ease-of-use)
In reconfigurable ( reconfiguring the lack of flexibility), it has already been identified as is a PC similar to the Achilles 'heel of Achilles' heel as further deployed. A combination of hardware and software mechanisms associated with next-generation bus architecture friendly graphical interface, so that the computer has less elusive ( confrontational ), and easy to reconfigure. However, from the perspective of an end user, the PC 's I / O interfaces, such as serial / parallel ports, keyboard / mouse / joystick interfaces, etc., are not Plug and Play ( Plug-and-Play properties).
Port Expansion ( Port Expansion)
Increased peripheral devices continue to be limited by the availability of a port. The lack of two-way, low cost, low to medium speed peripheral bus after the growth of innovative peripherals pull, such as storage devices, answering machine ( Answering Machines ), scanners, PDA , keyboard and mouse. Interconnection mechanism already exists for only one or two product optimization. With the new features and capabilities are added to the PC , the new interface is defined to meet this demand.
Initially, the USB provides two speeds for peripheral use. As the PC becomes more powerful, able to handle larger amounts of data, the user needs to PC import and export data between more and more. This leads to the USB 2.0 specification 2000 is defined out of, providing the first . 3 transmission rate of 480 Mb / S , while maintaining backward compatibility. In 2005 , with the wireless technology becomes more and more capability, Wireless USB is introduced to USB provides a new without cables ( Cable as Free ) capabilities.
USB is the most successful in the history of the definition of PC peripheral interconnect technology, and has rapidly being introduced into the CE and Mobile areas. Only in 2006 year there were more than 20 Yi USB device production, and now has more than 60 million USB products are installed. End-user "knows" what is the USB . Product developers understand the framework and interfaces necessary for construction products. USB has gone far beyond a peripheral connectivity PC mode. The printer uses USB to connect directly to the camera. PDA using a USB keyboard and mouse. USB On-The-Go 's definition provides a way for two devices can support dual roles and negotiate interconnection which will be used as a "host" to operate. The USB , as a protocol, is also selected, such as industrial automation for many non-traditional applications.
Now, with technological innovation continues to advance, new equipment, media formats, and cheap mass storage in emerging. They require higher bandwidth to maintain user desired user experience. HD cameras will have hundreds of GB storage contents need to be migrated to the PC end for users to edit, view, and package store. Further, the existing equipment, such as digital cameras continue to innovate and increase its capacity to accommodate more non-compressed image. Download hundreds or even thousands of years from a digital camera 10MB original picture or more would be a very time-consuming process, unless the transfer rate can be improved. Further, the user application requires PC connection between the higher bandwidth and increasing complexity of these peripherals. USB 3.0 to match these new devices and applications by increasing the higher transmission rate, in order to address these needs.
Therefore, the USB (wired or wireless) still is a PC answer connectivity issues between consumer electronics, mobile architecture. It is fast, two-way, low-cost, dynamic pluggable interfaces with the PC current and future needs of the platform is the same.
1.2 the target specifications (Objective of the Specification)
This document defines the next generation of USB industry standard, USB 3.0 . The specification defines the protocol described design and construction of the present specification compatible systems and peripherals, transmission type transaction, bus management and the programming interface.
USB 3.0 goals still need to enable interoperability between different vendors' equipment in this open architecture, as well as maintenance and use of existing USB infrastructure (device drivers, software, interfaces, etc.). The purpose of this code is to enhance the PC architecture, spanning mobile, business desktops, as well as family environment, as well as device-to-device ( Device-to-Device Communication) is. The goal is also that the system specification allows OEM vendors and peripheral developers plenty of room for diversity of product features and market discrimination, without the need to retain outdated interface or loss of compatibility.
1.3 specification scope (Scope of the Document)
This specification peripherals primary audience is the developer and platform / riser developers, but also provide valuable information to the platform operating system / BIOS / device drivers, riser IHVs / ISVs , and system OEMs . This specification can be used to develop new products and related software.
This specification is applicable to product developers need to know and understand the USB 2.0 specification. Specifically, the USB 3.0 devices must be implemented in a USB 2.0 device frame commands and descriptors defined in the specification.
1.4 USB Compatibility (USB Product Compliance)
USB3.0 specification adopters have signed USB3.0 Adopter Agreement, which provides for them from USB to get sponsors and other adopters of the specification a reasonable and non-discriminatory ( RANDZ ) license, which can use a specific compatible in USB3.0 specification of product intellectual property rights. Users can through the USB to prove the test procedures defined Implementers Forum compliant. Proof compliant products will be granted certain rights to use the USB logo Implementers Forum as a product signs.
1.5 Structure Specification (Document Organization)
The first one chapter to the first 4 chapters provide an overview of all readers, and the first 5 chapters to the first 11 chapters contains definitions USB 3.0 detailed technical information. Readers should contact your operating system vendor to obtain the operating system specific to USB 3.0 binding information.
1.6 design goal (Design Goals)
USB 3.0 is wired USB next stage of development. Our goal is to be regarded as the end-user with USB 2.0 the same, only faster. Several key design areas to achieve this goal are as follows:
- Maintain a smart host and simple device USB mode.
- Full use of existing USB infrastructure. Currently in use of USB products is a huge number. A large part of their success can be traced back to the existence of a stable software interface, the software is very easy to develop device drivers, as well as some common standard device class driver ( HID , mass storage, audio, etc.). Ultra high-speed USB device design to keep the infrastructure intact software, peripherals so developers can continue to use the same interface, and use of all existing development work.
- Significantly improve power management. Reducing active power transmission data, and to provide a richer set of power management mechanism, so that the device driving the bus low-power state, to reduce standby power consumption.
- Ease of use has been, and still is USB an important design goal for all species.
- Protection of investment. There are a large number of personal computers in use only support the USB 2.0 . As well as USB 2.0 larger number of peripheral devices. In A retaining backward compatibility with the connector, to allow the use of USB 2.0 a PC using the ultra high-speed devices, although at lower speeds; high-speed devices and allows the use of existing cable to the USB 3.0 ultrafast A connector work on the device.
1.7 Related Documents (Related Documents)
- Universal Serial Bus Specification, Revision 2.0
- USB On-the-Go Supplement to the USB 2.0 Specification, Revision 1.3
- Universal Serial Bus Micro-USB Cables and Connectors Specification, Revision 1.01
- EIA-364-1000.01: Environmental Test Methodology for Assessing the Performance of Electrical Connectors and Sockets Used in Business Office Applications
- USB 3.0 Connectors and Cable Assemblies Compliance Document
- USB SuperSpeed Electrical Test Methodology white paper
- USB 3.0 Jitter Budgeting white paper
- INCITS TR-35-2004, INCITS Technical Report for Information Technology – Fibre Channel –Methodologies for Jitter and Signal Quality Specification (FC-MJSQ)
