Interconnection Protocols Berk ÜSTÜNDAĞ Istanbul Technical University Computer Engineering Department

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 Unbalanced wired communication RS Balanced wired communication RS485 / RS Synchronous Serial Communication I2C Microwire SPI CAN BUS USB

2.2.6 IEEE1394 (Firewire) 3. NonWired communication techniques 3.1 Optical Communication IRDA Optical Fibers Laser 3.2 Radio Frequency Communication Frequency allocation (ETSI) Radiomodems Bluetooth IEEE GPRS, 3G, UMTS

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)

Microwire & SPI Interfaces

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

Parallel Printer Port – SPI EEPROM connection

2.2.5 USB

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.

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).

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 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 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.

...the interfacing solution

Agenda USB basics Why USB Bus structure Enumeration, speed Layer model Physical interface Transfer, transaction, packet 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 the interfacing solution Universal Serial Bus

Why USB ? Universal Serial Bus Ease of Use Plug and Play capabilities for “Outside the Box” peripherals You wanna more?!

USBUSB Universal Serial Bus USB Target Applications PERFORMANCEPERFORMANCEAPPLICATIONSAPPLICATIONS ATTRIBUTESATTRIBUTES HIGH SPEED Mb/s VideoDiskLAN High Bandwidth Very Low Latency Ease of Use Very Low cost Ease of Use Dynamic Attach-Detach Multiple Peripherals Very Low cost Ease of Use Dynamic Attach-Detach Multiple Peripherals Low cost Guaranteed Latency Higher Bandwidth Ease of Use Low cost Guaranteed Latency Higher Bandwidth Ease of Use LOW SPEED Kb/s LOW SPEED Kb/s Interactive Devices (Game, VR) Interactive Devices (Game, VR) MEDIUM SPEED 500Kb/s - 10Mb/s MEDIUM SPEED 500Kb/s - 10Mb/s ISDN, POTS, PBX, Audio, Imaging, Bulk Devices ISDN, POTS, PBX, Audio, Imaging, Bulk Devices " firewire" USB focus on LOW COST, HIGH VOLUME applications!

USB in 1996: Initially introduced as an additional connector for new applications. USB PC Connectivity Vision Universal Serial Bus Keyboard Mouse SerialPort ParallelPort SCSIPort Sound/GamePorts GraphicsPort LAN Modem GraphicsPort LAN USB Future: The PC evolves into a simpler, easier to use appliance. USBUSBUSB Telephony, Modem, Keyboard, Mouse,Game ports, Serial ports Device,Digital Audio, Printer, Scanner

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

...Topology... Universal Serial Bus 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

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

Universal Serial Bus 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

Device Abstractions... - Device Common features and interactions of devices Typically controlled by system software Universal Serial Bus - Function Highest level I/F between device driver and function - 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

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

USB Transfer types...basics 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. From1msto 255ms (FS) 10msto 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

Frame = 1msprinter Contro l USB Frame Model example Stereo Audio Telephony SOF low-speed Isochronou s Bul k Interrup t...basics printer any LS device like keyboard, mouse, etc. Bul k

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

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

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: 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

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

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

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

USB Connections and Terminations D- D+ R1R1 R 1 = 15K  ±5% R 2 = 1.5K  ±5% F.S./L.S. USB Transceiver Transceiver (45  Outputs) Host or Hub Port Z O = 90  ±15% 5 Meters Max. F.S. USB Transceiver Transceiver (45  Outputs) Hub Port 0 or Full Speed Function R1R1 R2R2 D- D+ R1R1 R 1 = 15K  ±5% R 2 = 1.5K  ±5% F.S./L.S. USB Transceiver Transceiver (45  Outputs) Host or Hub Port 3 Meters Max. L.S. USB Transceiver Transceiver (45  Outputs) Low Speed Function R1R1 R2R2 D+ D- D+ D- Twisted Pair Shielded Universal Serial Bus V CC GND Untwisted, Unshielded

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) Transaction n-1Transaction n-2Transaction n-3 Transfer n Transaction n-1 Universal Serial Bus, details

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

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

Packet Formats Sync.Packet ID Device Address ENDP Nr CRCEOP 8 bits 7 bits4 bits5 bits2 bits Sync.Packet IDData FieldCRCEOP 8 bits 16 bits 2 bits bytes Sync.Packet IDEOP 8 bits 2 bits Token Packet Data Packet Handshake/ Low Speed Preamble Sync.Packet IDFrame NumberCRCEOP 8 bits 11 bits5 bits2 bits SOF Token Packet Universal Serial Bus, details

IN Transaction without errors Token Packet defines the direction of the succeding Data Packet (here: IN = Data Packet from Device to Host) Data Packet carries the payload Handshake Packet reports error free reception of Data Packet IN Packet from Host Data Packet from USB Device to Host ACK Packet from Host ONE TRANSACTION Universal Serial Bus, details SyncEOPSync PID Data EOPSync PID ACK EOP PID IN Token Data Packet (Payload)

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 : = 21 full speed bytes times LS Transfer : 13 * * 8 = 168 full speed byte times (excluding Preamble) ~9,5% of bandwidth wasted TokenData Packet (8 bytes) Hand- shake one full speed transaction Preamble full speed low speed low speed Token full speed low speed PreambleData Packet (8 bytes) Hand- shake Universal Serial Bus, details

USB 2.0 Technical Overview Brad Hosler USB Engineering Manager Intel Corporation

Conference Goal Provide you with the information you need 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

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

Split Track: Focused Topics USB 2.0: Technical Agenda 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

Architecture Overview

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 equivalent of HS bandwidth

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

USB 2.0: What Didn’t Change? Same power distribution and consumption 500ua suspend, 100ma unconfigured, 500ma configured Same power management features Suspend/resume model unchanged Same topology management Hub features to handle connect, disconnect, enable, disable, … Same cables and connectors Continued

System SW Client Driver USB 1.1 Hub USB 1.1 Device HS Hub USB 1.1 Hub USB 1.1 Device HS Device USB 2.0 Host Controller Controller Full/Low Speed High Speed Only (2 x 12Mb/s Capacity) Sample USB 2.0 Topology Hub provides high-speed expansion (ala USB 1.1 hub) Hub provides additional Full/Low speed bus(es)

USB 2.0 Host Controller Allows port functionality regardless of OS version USB 1.1 OS will ‘just work’ as USB 1.1 ports USB 1.1 HCs can go away over time Replaced with integrated USB 2.0 Hub USB 2.0 Host Controller (HC) Port 1 USB 1.1 USB 1.1HCs High-Speed Mode (Enhanced Interface) USB HC Port 1Port 2 Port Owner Control(s) Port 1Port 2 Port Routing Logic Port N HC Control Logic/Data Buffering Enhanced HC Control Logic Enhanced Data Buffering Port 2Port N

USB 2.0 Hub Hub controller same as USB1.1 Routing logic connects device to appropriate path High Speed only Full/LowSpeed Routing Logic Port TransactionTranslatorTransactionTranslator HS Signal Repeater Repeater HubControllerHubController

Transaction Translator (TT) TT handles low/full speed transactions Driven with split transactions Start-Split Host tells Hub to initiate full/low speed transaction Complete-Split Host asks Hub for results of previous full/low speed transaction

Bandwidth Usage Low/full speed devices use bit-rate equivalent of USB2.0 bandwidth 6Mbps classic camera (50% of classic) uses less than 2% of USB2.0 bandwidth (6Mbps/480Mbps)

ISOCH IN Through a TT HS Bus Full Speed Bus uSOF 1ms uSOFuSOFuSOFuSOFuSOFuSOFuSOFuSOF SOFSOF SS SS = Start Split CSCSCSCS 125us CS = Complete Split

Demo: Full Speed Device Show the split transactions Show better performance behind USB 2.0 hub than behind USB 1.1 HC

Summary Two major changes for USB 2.0 Higher speed electricals Transaction translator in USB2.0 hub Backward compatibility Has little impact on HS bandwidth May even improve FS performance