1. USB (Universal Serial Bus)

2. What is USB? Universal Serial Bus (USB) is a serial bus standard to interface devices to a host computer It was designed to allow many peripherals to be connected using a single standardized interface socket and to improve the Plug and play capabilities by allowing hot swapping or hot plugging

3. Why? Ease of adding peripherals to PC Low cost, supporting transfer rates of up to 480 Mbps Support for many configurations of OS and PC’s Standard interface for peripherals in general Plug and Play technology No need for external power

4. Overview Multiple peripheral devices connected in a tiered-star topology up to 5 levels Up to 127 devices, including the hub device USB 1.0, 1.1 and 2.0 use a "speak-when-spoken- to“ protocol Offers limited power

5. How was it created? USB was developed by a consortium of large companies, such as: -Microsoft; -IBM; -Apple; -Hewlett-Packard; -NEC; -Intel; -Compaq; -Digital; -Northern Telecom; -Philips; -...

6. Obviously it was very difficult for these companies enter into agreement Intel - UHCI - Universal Host Controller Interface (transfer part of the protocol processing for the software (driver), simplifying the electronic controller) Compaq, Microsoft, National Semiconductor – OHCI - Open Host Controller Interface (transfer most of the effort to the electronic controller, simplifying the driver software (driver)) 2.0 – EHCI - Enhanced Host Controller Interface (combines quality of the two models with a greater bandwidth) Curiosity about the consortium

7. Device Classes USB defines class codes used to identify a device’s functionality and to load a device driver based on that functionality ClassUsageDescriptionExamples 00hDeviceUnspecified class 0 class 0 (Device class is unspecified. Interface descriptors are used for determining the required drivers.) 01hInterfaceAudioSpeakerSpeaker, microphone, sound cardmicrophonesound card 02hBothCommunications and CDC ControlEthernet adapterEthernet adapter, modem, serial port adaptermodemserial port adapter 03hInterfaceHuman Interface Device (HID)KeyboardKeyboard, mouse, joystickmouse 05hInterfacePhysical Interface Device (PID)Force feedback joystick 06hInterfaceImageDigital cameraDigital camera (Most cameras function as Mass Storage for direct access to storage media). 07hInterfacePrinterLaser printerLaser printer, Inkjet printerInkjet printer 08hInterfaceMass StorageUSB flash driveUSB flash drive, memory card reader, digital audio player, external drivesmemory cardreaderdigital audio player 09hDeviceUSB hubFull speed hub, hi-speed hub 0AhInterfaceCDC-Data(This class is used together with class 02h - Communications and CDC Control.) 0BhInterfaceSmart CardUSB smart card reader 0DhInterfaceContent Security- 0EhInterfaceVideoWebcam 0FhInterfacePersonal Healthcare- DChBothDiagnostic DeviceUSB compliance testing device E0hInterfaceWirelessWireless ControllerWi-FiWi-Fi adapter, Bluetooth adapterBluetooth EFhBothMiscellaneousActiveSyncActiveSync device FEhInterfaceApplication SpecificIrDAIrDA Bridge FFhBothVendor Specific(This class code indicates that the device needs vendor specific drivers.)

8. USB Connectors

9. Cable The maximum length of a standard USB cable is 3.0 meters (1.1) or 5.0 meters (2.0) Maximum hubs connected in series is 5 Maximum distance of 30 meters between host and device - because of the delay The data cables are a Twisted pair to reduce noise and crosstalk

10. PinNameCable colorDescription 1VCCRed+5V 2D−WhiteData − 3D+GreenData + 4GNDBlackGround Miniplug/Microplug PinNameColorDescription 1VCCRed+5 V 2D−WhiteData − 3D+GreenData + 4IDnone permits distinction of Micro-A- and Micro-B- Plug Type A: connected to Ground Type B: not connected 5GNDBlackSignal Ground

11. USB Versions USB 0.7: Released in November 1994 USB 0.8: Released in December 1994 USB 0.9: Released in April 1995 USB 0.99: Released in August 1995 USB 1.0: Released in January 1996, with data transfer rates of 1.5 Mbit / s USB 1.1: Released in 1998 USB 2.0: Released in April 2000

12. USB 1.1 Specified data rates of 1.5 Mbit/s (Low-Speed) and 12 Mbit/s (Full- Speed) Standard interface Fixed problems identified in 1.0, mostly relating to hubs Used for small peripherals

13. USB 2.0 Added higher maximum speed of 480 Mbit/s (now called Hi-Speed) Uses the same standart connector Compatible with 1.1 devices but with reduced speed Manufacturers could adopt the standard into their products without the obligation to pay a license to use the technology There was an increase in the range of possibilities because of the hi- speed

14. USB 3.0 A SuperSpeed rate of 5.0 Gbit/s, 10 times faster than 2.0 Products using the 3.0 specification are likely to arrive in 2009 or 2010 The trade name will be SuperSpeed USB The technology is similar to PCI Express 2.0 (5-Gbit/s) - comparing the cables

16. Applications and Utilities

18. hugo.baldioti@engenharia.ufjf.br