USB-mkezele-eseary-20090401

Universal Serial Bus : 

Universal Serial Bus Evann Seary Mike Kezele

Content Overview : 

Content Overview History of USB Overview Future of USB USB 3.0 WUSB

Overview : 

Overview Key features of USB: Low cost Single connector type Hot pluggable Device handling Cable power

USB : 

USB USB 1.0 specification introduced in 1994 USB 2.0 specification finalized in 2001 Became popular due to cost/benefit advantage Eg. IEEE 1394 – high bandwidth, high cost Three generations of USB USB 1.0 USB 2.0 USB 3.0 and WUSB

USB 3.0 Overview : 

USB 3.0 Overview Also referred to as SuperSpeed USB Speeds 10x faster than 2.0 (5 Gbps in controlled test environment) Transfer of 25 GB file in approx 70 seconds (see chart) Extensible – Designed to scale > 25Gbps Optimized power efficiency No device polling (asynchronous notifications) Lower active and idle power requirements Backward compatible with USB 2.0 USB 2.0 device will work with USB 3.0 host USB 3.0 device will work with USB 2.0 host

USB 3.0 - Timeline : 

Promoter Group: Hewlett-Packard, Intel, Microsoft, NEC, ST-NXP Wireless and Texas Instrument Contributors Group contained over 200 companies (Nov 2007) USB 3.0 Specification became available Nov 2008 USB 3.0 - Timeline

USB 3.0 Connectors : 

USB 3.0 Connectors Added pins for SuperSpeed USB signals Compatibility for USB 2.0 connectors USB 3.0 Standard B connector (middle) contains power and ground pins for device to supply power

USB 3.0 Bus Architecture : 

USB 3.0 Bus Architecture Operates concurrently with USB 2.0 (Dual bus architecture) Mechanically and electrically backward/forward compatible Devices configured at fastest signaling rate Hubs contain additional ports Speed and power efficiency Non polling reduces power consumption Additional data lines included to increase speed Efficiency of bandwidth – simultaneous communication between host and device Dedicated in and out lines allow communication between host and device

USB 3.0 Architecture Cont. : 

USB 3.0 Architecture Cont. Physical Layer Adopted from current industry specs Signaling similar to existing high-speed buses PCI Express SATA

USB 3.0 Packet Handling : 

USB 3.0 Packet Handling All data transfers initiated by host Hub can be up to 5 layers deep (127 devices) Packets routed NOT broadcast Hubs use “store and forward” procedures Packets held by hub which are being directed to inactive port Downstream packets use route string to navigate to device Upstream always contains host as destination

USB 3.0 Power Management : 

USB 3.0 Power Management Host to Device Sends PPT (Packet Pending Transfer) When no PPT, device can reduce power usage Use of packet suspension and asynchronous notifications Hub inactivity timers

Wireless USB : 

Wireless USB WUSB is a form of USB technology that uses radio-frequency (RF). WUSB technology is based on the WiMedia Ultra-Wideband common radio platform. WUSB can provide transfer rates up to 480 Mbps (at 3 m) or 110 Mbps (at 10 m). WUSB also allows for no more then 127 devices connected to a single host controller.

What is Ultra-Wideband : 

“UWB is a radio technology that can be used at very low energy levels for short-range high-bandwidth communications by using a large portion of the radio spectrum” [1] Broader spectrum and lower power improves speed and reduces interference of other devices What is Ultra-Wideband

What is UWB cont’d : 

UWB differs substantially from other narrowband RF and SS, such as: Bluetooth Technology 802.11a/b/g. Also allows for more data transfer in a given period of time. What is UWB cont’d

Why Wireless USB : 

Why Wireless USB The demand for increased connectivity without the clutter Preserves the USB 2.0 layered architecture and communication flow Point-to-point Same transfer types, etc WUSB interface still offers Plug and Play capability as well as hot swap hardward components Maintains Backward Compatibility (1.0 and 2.0)

Architectural Overview : 

Architectural Overview A USB system consists of a host and some number of devices all operating together on the same time base and logical interconnect. USB system can be described by three definitional areas: USB interconnect USB devices USB host USB interconnect is the manner in which USB devices are connected to and communicate with the host. This includes the following: Topology Data Flow Models USB Schedule

Topology : 

Topology WUSB uses a “hub and spoke” model WUSB host is the ‘hub’ and devices sit on the end of a ‘spoke’ Each spoke provides a point-to-point connection

Bus Protocol : 

Bus Protocol WUSB is polled, TDMA based protocol (similar to wired USB) The Host Controller initiates all data transfers Consists of 3 packets: Token Data Handshake

Bus Protocol cont’d : 

Bus Protocol cont’d To increase efficiency and eliminate costly sending and receiving transitions The hosts combine multiple token information into a single packet In this packet the host indicates the specific time when: The devices should listen for data OUT or transmit an IN data packet or Handshake

Applications : 

Applications Wireless video display Home and office MP3s General data transfer And More

References : 

References USB System Architecture By Don Anderson http://www.rfcafe.com/vendors/components/ultra-wideband-uwb.htm[1] http://www.reghardware.co.uk/2008/08/14/intel_posts_usb_3_hci_spec/ www.usb.org http://www.intel.com/technology/comms/uwb http://www.intel.com/technology/comms/wusb/index.htm http://www.ece.ucsb.edu/~rajeev/data/courses/engr103/paper.pdf http://whatis.techtarget.com/definition/0,,sid9_gci1188752,00.html http://isi.edu/nsnam/ns/doc/node178.html http://www.reghardware.co.uk/2008/11/18/usb_3_completed/ http://www.reghardware.co.uk/2008/01/09/ces_usb_3_revealed/ http://www.reghardware.co.uk/2008/08/14/intel_posts_usb_3_hci_spec/ http://www.everythingusb.com/usb2/faq.htm

Questions : 

Questions ???