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Interconnection Protocols

Interconnection Protocols. Berk ÜSTÜNDAĞ Istanbul Technical University Computer Engineering Department berk@cs.itu.edu.tr http://berk.tc. Contents (Part 3/7). 1.Introduction 1.1 Goals of the lecture 1.2 OSI Reference Model 2. Wired communication techniques

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Interconnection Protocols

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  1. Interconnection Protocols Berk ÜSTÜNDAĞ Istanbul Technical University Computer Engineering Department berk@cs.itu.edu.tr http://berk.tc

  2. Contents (Part 3/7) 1.Introduction 1.1 Goals of the lecture 1.2 OSI Reference Model 2. Wired communication techniques 2.1 Asynchronous Serial Communication 2.1.1 Unbalanced wired communication RS232 2.1.2 Balanced wired communication RS485 / RS422 2.2 Synchronous Serial Communication 2.2.1 I2C 2.2.2 Microwire 2.2.3 SPI 2.2.4 CAN BUS 2.2.5 USB

  3. 2.2.6 IEEE1394 (Firewire) 3. NonWired communication techniques 3.1 Optical Communication 3.1.2 IRDA 3.1.2 Optical Fibers 3.1.3 Laser 3.2 Radio Frequency Communication 3.2.1 Frequency allocation (ETSI) 3.2.2 Radiomodems 3.2.3 Bluetooth 3.2.4 IEEE802.11 3.2.5 GPRS, 3G, UMTS

  4. 4. Mobile Data Transfer 4.1 Smart Cards 4.2 Contactless Smart Cards 4.3 Touch Memory 4.4 Magnetic Strips (Cards) 4.5 PCMCIA cards 5. Application Examples 5.1 GPS (NMEA protocol), vehicle tracking 5.2 Can Bus – automative applications 5.3 Virtual Money 5.4 Mobile officers, PDA 5.5 PC AT keyboard interface 5.6 Pay TV 5.7 Energy meter (PLC-Power line data collection)

  5. Microwire & SPI Interfaces

  6. The serial peripheral interface (SPI) is a general purpose synchronous serial interface originally found on cerrtain Motorola microcontrollers.

  7. Parallel Printer Port – SPI EEPROM connection

  8. 2.2.5 USB

  9. What is the Universal Serial Bus? The USB is a relatively recent way to connect instruments and devices to the PC. Most new computers have one or two USB ports, in addition to the familiar RS232 (COM) and parallel ports. You can use the USB ports to connect peripherals like digital cameras, printers and data acquisition and control units.

  10. The USB is extremely convenient for data acquisition for several reasons. • The equipment can obtain power from the USB; it doesn't need to be battery powered or plugged into the wall. This makes USB ideal for portable data acquisition with a laptop. • Using a USB hub you can connect many devices to one USB port - letting you easily expand your system should requirements grow. • USB ports are provided on most new PCs - no need to open the computer and install adaptor cards. • You can plug in and unplug your equipment without switching off your computer or even restarting Windows. • The USB cable can be up to 5 m long. However, using USB hubs between cables you can reach 30m. • Faster speeds than those allowed by RS232 connections are achievable • You can use USB devices alongside existing data acquisition equipment (such as cards that you've installed in your PC or instruments that plug directly into the RS232 port).

  11. Transferring data at 480 Mbps, USB 2.0's claim to fame is that it's 40 times faster than USB 1.1 — and a touch faster than FireWire's 400 Mbps. In addition, the new standard is backward-compatible with USB 1.1, so users can continue to use USB 1.1 peripherals (but won't receive the speed benefits of 2.0). According to Venture Development Corp. (VDC), a Natick, Mass.-based analyst firm, this bodes well for USB. The firm's recent study of cable shipments ("The U.S. Aftermarket for Computer Accessories, 4th Edition") shows USB cables made up 30 percent of total U.S. aftermarket cable shipments in 2001. VDC predicts USB will overtake other cable types this year in shipments, contributing to a predicted annual growth rate of more than 42 percent through 2006.Another boost for USB 2.0 is Microsoft's decision to offer USB 2.0 drivers for Windows XP. However, the Redmond, Wash.-based firm does so cautiously, noting there have been some issues with the drivers. Apple Computer still remains on the fence regarding USB 2.0, stating that it's evaluating the upgrade and weighing it against the upcoming change to the FireWire standard.

  12. ISDN ...the interfacing solution

  13. Agenda • USB - ISDN Terminal Adapter (TA) • Standard TA (PC ISDN card) - USB TA • Endpoints usage, ISDN data format • Hardware implementation, Buffering • B-channel performance • Layer model USB TA  PC ISDN card • D-channel signalization through USB • D-channel performance • Hardware platform, tools • SAB-C541U • USB basics • Why USB • Bus structure • Enumeration, speed • Layer model • Physical interface • Transfer, transaction, packet

  14. USBthe interfacing solution Universal Serial Bus

  15. Why USB ? • Ease of Use • Plug and Play capabilities for “Outside the Box” peripherals Youwanna more?! Universal Serial Bus

  16. ATTRIBUTES PERFORMANCE APPLICATIONS USB Target Applications Very Low cost Ease of Use Dynamic Attach-Detach Multiple Peripherals LOW SPEED 10 - 100 Kb/s Interactive Devices (Game, VR) USB USB focus on LOW COST, HIGH VOLUME applications! Low cost Guaranteed Latency Higher Bandwidth Ease of Use ISDN, POTS, PBX, Audio, Imaging, Bulk Devices MEDIUM SPEED 500Kb/s - 10Mb/s 1394+"firewire" Video Disk LAN High Bandwidth Very Low Latency Ease of Use HIGH SPEED 50 - 1000 Mb/s Universal Serial Bus

  17. USB in 1996: Initially introduced as an additional connector for new applications. USB Keyboard Serial Port Sound/Game Ports Modem LAN Mouse USB Future: The PC evolves into a simpler, easier to use appliance. Parallel Port Graphics Port SCSI Port USB USB USB Telephony, Modem, Keyboard, Mouse,Game ports, Serial ports Device,Digital Audio, Printer, Scanner Graphics Port LAN PC Connectivity Vision Universal Serial Bus

  18. HOST/HUB PC HUB Monitor HUB Kbd USB Pen Mouse Speaker Mic Phone Hardware Overview... • Topology • Tiered Star (Distributes Connectivity Points) • 127 logical connections (upto 5 meters per segment) • Upto 6 tiers • ... Universal Serial Bus

  19. ...Topology... • Host • One PC host per system • Hub • Provides connecting ports, power, terminations • Self-Powered or Bus Powered • Device, Function and End-points • Device is a collection of function(s) • Function is a collection of end-points • Upto 127 functions and 16 end-points per function Universal Serial Bus

  20. Host Host Root Hub Root Hub Device Device HUB HUB Device Device Device Device Device Device HUB HUB Device Device Device Device USB Configuration ProcessEnumeration • Host Software is responsible for Device configuration • Hot Plug and Play feature • Device attachment on Hub port • Device is detected • Downstream port is enabled • Configuration of Device by Host • Process of Configuration is accomplished via Control Transfers Universal Serial Bus, details

  21. Hardware Overview • Bus transactions • Speed: 12Mbps full-speed 1.5Mbps low-speed • Isochronous and Asynchronous • Media access controlled by host • Configuration, Hot Plug-And-Play • Dynamic insertion-removal • Autoconfiguration on change • Physical Layer • 2-wire differential signaling, NRZI coded with bit stuffing • Supply Sourcing +5V • Signaling at CMOS 3.3V • 4 pin connector, 4 wire cable Universal Serial Bus

  22. Device Abstractions... • Device • Common features and interactions of devices • Typically controlled by system software • End Point • Ultimate data source or sink at the device end • Each endpoint is unidirectional and has a transfer type associated with it‘s Peripheral • Function • Highest level I/F between device driver and function Universal Serial Bus

  23. Device Function Function Abstraction Driver Endpoint Endpoint Endpoint USB USB Device Device Abstraction Software I/F Host USB Physical Connect Controller Hardware ...Device Abstractions Device, like modem, keyboard mouse, etc PC Universal Serial Bus

  24. USBTransfer types • Control (e.g.: configuration, messages) • bursty, host initiated (bus management, configuration) • guaranteed bandwith of max. 10% • error-free data delivery guaranteed • Interrupt (e.g.: mouse, joystick....) • small bursty, low bandwidth required • error-free data delivery guaranteed • polling is used (by host) to check for "interrupt events” • polling intervall programmable. From 1ms to 255ms (FS) 10ms to 255ms (LS) • Isochronous (e.g.: audio, telephony.....) • for data which need to be periodically sent • predictable latency on data delivery. • no error check, error-free data delivery is not guaranteed • Bulk (e.g.: printer, scanner, still camera.....) • non periodic, bursty, ideal for large amounts of data • error-free data delivery guaranteed ...basics

  25. Bulk Control Frame = 1ms Stereo Audio SOF Telephony low-speed SOF Bulk Isochronous Interrupt any LS device like keyboard, mouse, etc. USB Frame Modelexample printer printer ...basics

  26. HUB / DEVICE HOST PC / HUB CABLE connector 'upstream' CABLE connector 'downstream' Power pair max. 5m Differential Signal pair Connectors and Cables • Connectors • 4-Position with shielded housing • Positive Retention • Blind Mating Capabilities Universal Serial Bus

  27. Downstream Connectivity Upstream Connectivity Hub Repeater Hub Repeater Disabled Port Enabled Ports USB Hub Function • Port Control • Connection detect • Port Enable/ Disable • Reset/ Resume Signaling • Data Switch • Signal Regeneration • Robustness/ Recovery • Power Distribution Universal Serial Bus

  28. Power Distribution • Significant capability of USB • Eliminate wall adaptors • Hubs may be self-powered or bus-powered • Two current levels: 100 & 500 mA • Overcurrent protection for safety • Wire gauge options: 20-28 AWG • Suspend • All devices support suspend • Enter suspend state after seeing idle bus for 3 ms • Suspend current  500 A from bus • Resume • USB devices can cause “remote wake-up”e.g. Modem wakes up the system Universal Serial Bus

  29. 4.65V (min) 4.40V (min) Bus-Powered Host or Bus-Powered Hub Function Powered Hub 4.0V (as a resulting low value) Voltage Drop • Voltage drop per wire/connector: 0.125 V • Budget for power switch: 0.100 V Universal Serial Bus

  30. Data Signaling • Bi-directional, half-duplex link • Embedded clock and data • Differential signal pair • 12 Mbit / sec Full Speed (FS) bit rate • 1.5 Mbit / sec Low Speed (LS) bit rate Universal Serial Bus

  31. Low Speed • 1.5 Mb/s • Unshielded, untwisted cable • Saves EMI suppression costs • 1.5% Frequency tolerance • Driver characteristics • Rise/ Fall time: Min 75ns, Max 300ns • Required on low speed functions and on the downstream ports of Hubs • Allows very-low-cost devices to be built without compromising data rate for faster devices • Mice, keyboards, most user interface peripherals don’t need fast data rate • Eliminates need for shielded twisted pair cable (3 meters) • Allows use of less-expensive IC process technology Universal Serial Bus

  32. USB Connections and Terminations VCC R2 D+ D+ F.S./L.S. USB Transceiver F.S. USB Transceiver R1 Twisted Pair Shielded D- (45Outputs) D- ZO = 90±15% 5 Meters Max. (45Outputs) GND Hub Port 0 or Full Speed Function R1 Host or Hub Port R1 = 15K±5% R2 = 1.5K±5% GND D+ D+ F.S./L.S. USB Transceiver L.S. USB Transceiver VCC R1 Untwisted, Unshielded R2 D- (45Outputs) GND 3 Meters Max. (45Outputs) D- R1 R1 = 15K±5% R2 = 1.5K±5% Host or Hub Port Low Speed Function GND Universal Serial Bus

  33. Transfer n Transaction n-1 Transaction n-2 Transaction n-3 Transaction n-1 Transfer - Transaction - Packet (1) • Host Software initiates Transfer from or to a target USB Device • Host software splits up one Transfer into one or more Transactions • Transactions are set up based on the Device's characteristics (Packet Size, Transfer Type) Universal Serial Bus, details

  34. Transfer - Transaction - Packet (2) • Host Software schedules and executes Transactions during 1ms Frames • Each Frame consists of several Transactions from different Transfers Universal Serial Bus, details

  35. Transfer - Transaction - Packet (3) • Each Transaction consists of a series of packets • Token Packet defines the Type of Transaction • Data Packet carries the payload to or from a Device • Handshake Packet provides feedback about correct data transfer to sender Universal Serial Bus, details

  36. 8 bits 8 bits 7 bits 4 bits 5 bits 2 bits Device ENDP Sync. Packet ID CRC EOP Address Nr 8 bits 8 bits 11 bits 5 bits 2 bits Sync. Packet ID Frame Number CRC EOP 8 bits 8 bits 0-1023 bytes 16 bits 2 bits Sync. Packet ID Data Field CRC EOP 8 bits 8 bits 2 bits Sync. Packet ID EOP Packet Formats Token Packet SOF Token Packet Data Packet Handshake/ Low Speed Preamble Universal Serial Bus, details

  37. Data Packet from IN Packet from Host ACK Packet from Host USB Device to Host PID PID PID Sync EOP Sync Data Packet (Payload) EOP Sync EOP IN Token Data ACK ONE TRANSACTION IN Transaction without errors • Token Packetdefines the direction of the succeding Data Packet (here: IN = Data Packet from Device to Host) • Data Packet carries the payload • Handshake Packetreports error free reception of Data Packet Universal Serial Bus, details

  38. Hand- Token Data Packet (8 bytes) shake one full speed transaction Hand- Preamble Token Preamble Data Packet (8 bytes) shake full low full low speed low speed speed speed speed Low Speed - Full Speed Transaction • Protocol overhead for FS and LS Transfers is 13 bytes Payload for FS and LS is 8 bytes • FS Transfer : 13 + 8 = 21 full speed bytes times • LS Transfer : 13 * 8 + 8 * 8 = 168 full speed byte times (excluding Preamble) • ~9,5% of bandwidth wasted Universal Serial Bus, details

  39. USB 2.0 Technical Overview Brad Hosler USB Engineering Manager Intel Corporation

  40. Conference Goal • Provide you with the information youneed to build USB 2.0 products • USB 2.0 technical details • USB 2.0 Infrastructure • Building USB 2.0 devices • USB 2.0 Building Blocks

  41. USB 2.0: Conference Agenda Single Track:Topics for Everyone • Architecture Overview • Peripheral Development Enabling • USB 2.0 Compliance and Logo Program • USB 2.0 Compliance Testing

  42. USB2 Specifications Electricals Protocol Hubs Power Management Host Controller Spec Cable Testing USB “On the Go” USB2 Software MS Roadmap Driver Testing HS Isoch Interface Building USB2 Devices Design Options Transceiver Macrocell Firmware and Testing Analyzers Platform Design BIOS USB 2.0: Technical Agenda Split Track: Focused Topics

  43. ArchitectureOverview

  44. USB 2.0: What Changed?? • Low level electricals for High Speed (HS) signaling • Much higher bit rate (480Mb/s) requires new transmitter/receiver • Hub changes for backward compatibility • Features limit bandwidth impact of Full Speed (FS)and Low Speed (LS) devices on HS devices • FS/LS devices consume a bit-rate equivalentof HS bandwidth

  45. USB 2.0: What Didn’t Change? • Same host/device model • Host is in charge • Devices are inexpensive • Same basic protocol • Token, data, handshake • Same device framework • Descriptors • Same software interfaces • USBDI

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