1. February 10 th 2010 Dehmani Feth-Allah M2 ISTRe Oral Presentation Universal Serial Bus

2. II. How does it work ? Summary I. Presentation (Where, When, Why…) III. Applications HOW DOES IT WORK ? APPLICATIONS USB PRESENTATION February 10 th 2010

3. Presentation HOW DOES IT WORK ? APPLICATIONS USB PRESENTATION February 10 th 2010 Purpose : Standardization of serial communication between a host and a device with a unique connexion and a unique communication protocol Invented in 1996 by Microsoft, IBM, Intel, Compaq, Digital, NEC et Northern Telecom (USB 1.0) Before invention of USB :  Differents connexion port and protocol communication like RS-232, parallel, PS-2 or SCSI. Generalities:

4. Presentation HOW DOES IT WORK ? APPLICATIONS USB PRESENTATION February 10 th 2010 HOST DEVICE Hardware connexions :

5. February 10 th 2010 4. GND 1. VDD 2 & 3. DATA (D+ & D-) Signal connexions : How does it work ? HOW DOES IT WORK ? APPLICATIONS USB PRESENTATION

6. How does it work ? HOW DOES IT WORK ? APPLICATIONS USB PRESENTATION February 10 th 2010 NRZI diferential encryption between D+ and D- LSB first transmit (Little Endian). Speed USB release1.01.12.03.0 Year1996199820002010 Speed1,5 Mbit/s Low Speed 12 Mbit/s Full Speed 480 Mbit/s High Speed 4,8 Gbit/s Super Speed USB Bus description

7. How does it work ? HOW DOES IT WORK ? APPLICATIONS USB PRESENTATION February 10 th 2010 « Host – Slave » system Frame transmission (Token et Data) 8 bits 7 bits4 bits5 bits SYNCPIDADDRESSENDPCRC 8 bits 0 to 512 bits16 bits SYNCPIDPAYLOADCRC Token frame DATA frame Communication protocol :

8. How does it work ? HOW DOES IT WORK ? APPLICATIONS USB PRESENTATION February 10 th 2010 Control : for command operation (enumeration, state of the device…) Interrupt : for device with garanted time delay (mouse, keyboard…) Isochrone : for device with garanted bit rate (garanted bandwidth : ex : printer, camera…) Bulk : for big data transmissions (take maximum bandwidth as possible) Transmission :

9. How does it work ? HOW DOES IT WORK ? APPLICATIONS USB PRESENTATION February 10 th 2010 Identification process of the device by the host SPEED DETECTION DEVICE IDENTIFICATION Send descriptors CONNEXION High level in D+ ou D- Enumeration:

10. Applications HOW DOES IT WORK ? APPLICATIONS USB PRESENTATION February 10 th 2010 REAL TIME APPLICATIONS DATA TRANSFER OR CONTROL COMMAND USB BUS ENERGY (only hardware, 500mA max)

11. Conclusion February 10 th 2010 Today, USB is one of the most serial protocole used FireWire (Apple) is the alternative of USB (3 200 Mbits/s) To sell USB device, you need to buy a Vendor ID (≈ 2000 $ US / year)

12. Thank You…