Technology Primer - USB 3.0 SuperSpeed

Initially, USB provided two speeds (1.5 Mb/s and 12 Mb/s). As PCs became increasingly powerful and able to process larger amounts of data, users needed to get more and more data into and out their PCs. This led to the definition of USB 2.0 specification to provide a transfer rate of 480 Mb/s while retaining backward compatibility.

As technology innovation marches forward, new kinds of devices, media formats, and large inexpensive storage are converging. They require significantly more bus bandwidth to maintain the interactive experience users have come to expect. In addition, user applications demand a higher performance connection between the PC and these increasingly sophisticated peripherals. USB 3.0 SuperSpeed addresses this need by adding an even higher transfer rate to match these new usage and devices.

SuperSpeed USB 3.0 supports a maximum data rate of 4.8 gigabits per second offering 10x performance increase over Hi-Speed USB (USB 2.0)
USB 3.0 is full duplex, meaning it can upload and download simultaneously (it's bi-directional); USB 2.0 is only half duplex
Backwards compatibility with USB 2.0 hi-speed devices
USB 3.0 has got dual bus architecture means SuperSpeed bus operates concurrently with USB 2.0
SuperSpeed USB is a Sync-N-Go technology that minimizes user wait-time.
SuperSpeed USB will provide improved power efficiency. No device polling and lower active and idle power requirements
USB 3.0 SuperSpeed creates a communication pipeline with host and each device or a "host-directed protocol". The older USB 2.0 Hi-Speed broadcasted packets to all devices.
Cable makeup: 2 wires for power and ground, 2 for Hi-Speed backward compatibility, 4 wires for the new Superspeed
Shielded differential pair (SDP, twisted or twinax) is needed for USB 3.0. UTP cable used for USB 2.0 can not be used for USB 3.0
USB 3.0 cable can be upto 3 meters to maintain SuperSpeed data transfer rates
USB 3.0 SuperSpeed can handle more power over its cable. 50% more than USB 2.0
USB 3.0 has dual simplex and asynchronous notifications
USB 3.0 Standard-A connector has complete compatibility with USB 2.0 Standard-A connector. However, a new receptacle has been created "USB 3.0 Standard-B" which can only accept a USB 3.0 Standard-B device plug.

Fig: USB 3.0 Standard-A Connector

The USB3.0 specification was developed by the USB3.0 promoter group which consists of Intel, HP, Microsoft, NEC, ST-Ericsson and Texas Instruments.

2. Comparison of USB 3.0 to USB 2.0

Features	USB 3.0	USB 2.0
Speed	up to 4.8 Gb/s	up to 480 Mb/s
Signalling	Dual-simplex four wire differential signalling	Two wire differential signalling
Data flow	Full duplex	Half duplex
Power Management	Multi-level which supports idle, sleep, and suspend	Port-level that has two levels of entry/exit latency
Cable types	Shielded differential pair (SDP)	Unshielded twisted pair (UTP)
Cable Wires	8 total	4 total
Traffic Flow	Asynchronous	Polled
Packet Traffic	Explicitly routed	Broadcast to all devices
Bus Power	900mA, 5V	500mA, 5V

3. Standards

The USB 3.0 specifications are freely available from the USB-IF (implementer’s forum) at: http://www.usb.org/developers/docs/

Compliance testing specifications are also available http://www.usb.org/developers/ssusb/testing

4. Industry Associations

There really is only the one and it’s a good place to start further reading. http://www.usb.org/developers/ssusb/

5. Certification

To use the SuperSpeed USB3.0 Certified symbol on a product, that product must be officially certified by the USB Implementation Forum (USB-IF) to support USB 3.0 features.

There is a SuperSpeed USB Platform Integration Lab (PIL) available for assistance with SuperSpeed product development. The lab is open for USB-IF members only.

Due to increased demand for SuperSpeed USB product certification, the PIL lab is reducing test days needed to complete USB 3.0 certification. To achieve this goal, all SuperSpeed peripherals and end user hosts/hubs that are based on certified silicon are required to complete USB 2.0 compliance tests at a third part authorized test lab.

6. USB 3.0 Tools

Useful USB3.0 software and hardware test tools are available from http://www.usb.org/developers/ssusb/ssusbtools/

USB 3.0 Command Verifier (USB30CV) is the official tool for USB 3.0 (SuperSpeed USB) Hub and Device Framework testing. All USB 3.0 peripherals are required to pass the Device Framework tests in order to gain certification.

7. Other Technical Resources

7.1 Datasheets

http://america2.renesas.com/usb/product/upd720200.html A link to world's first USB host controller chip compliant with the USB 3.0

http://www.faraday-tech.com/downloadDoc/documentation/Faraday_USB3.0_Transceiver_PHY_FTC-2009-05.pdf Faraday USB3.0 Transceiver/PHY

http://focus.ti.com/lit/ds/symlink/sn65lv e502.pdf SN65LVPE502RGETSN65LVPE502RGET Dual Channel USB3.0 Redriver/Equalizer

http://focus.ti.com/lit/ds/symlink/tusb1310.pdf TUSB1310ZAYTUSB1310ZAY USB3.0 Transceiver

http://www.murata.com/products/article/pdf/ta09b1.pdf A link to SuperSpeed USB3.0-compliant common mode choke coil

7.2 Forums

http://www.usb.org/developers/forum/ A link to USB IF developers forum.

7.3 Analysers

Analyser for USB3.0 SuperSpeed traffic monitoring, driver and software stack debugging, and performance analysis:

http://www.ellisys.com/products/usbex280/index.php

http://www.lecroy.com/ProtocolAnalyzer/ProtocolOverview.aspx?seriesid=164&capid=103&mid=511

8. Books and Associated Literature

Currently Premier Farnell do not stock textbooks on USB3.0 or USB3.0 device functions.

Different USB3.0 SuperSpeed presentations and white papers are available in the below link-

http://www.usb.org/developers/docs/presentations

http://www.usb.org/developers/whitepapers/

9. Adding USB 3.0 Communications to Your Product

9.1 Host Controller

USB 3.0 Host controllers-

uPD720200 - http://america2.renesas.com/usb/product/upd720200.html

FL1000FL1000 - http://www.frescologic.com/news-0_2.html

9.2 Device Controller

USB 3.0 Device Controllers-

MB86C30 - http://www.fujitsu.com/emea/news/pr/fme_20090727-954.html

JMS539 - http://www.jmicron.com/Product_JMS539.htm

Tags: ap:usb, at:tech_primer