Interconnection Protocols Berk ÜSTÜNDAĞ Istanbul Technical University Computer Engineering Department [email protected]@cs.itu.edu.tr

Interconnection Protocols

Berk ÜSTÜNDAĞIstanbul Technical UniversityComputer Engineering [email protected] http://berk.tc

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

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. 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 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.

...the interfacing solution...the interfacing solution

AgendaUSB 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

USBthe interfacing solution

Universal Serial Bus Universal Serial Bus

Why USB ?


Ease of Use Plug and Play capabilities for “Outside the Box” peripherals

Youwanna more?!

USBUSBUSBUSB


USB Target ApplicationsPERFORMANCE PERFORMANCE PERFORMANCE PERFORMANCE APPLICATIONSAPPLICATIONSAPPLICATIONSAPPLICATIONS ATTRIBUTESATTRIBUTESATTRIBUTESATTRIBUTES

HIGH SPEEDHIGH SPEED50 - 1000 Mb/s50 - 1000 Mb/sHIGH SPEEDHIGH SPEED50 - 1000 Mb/s50 - 1000 Mb/s

VideoVideoDiskDiskLANLAN

VideoVideoDiskDiskLANLAN

High BandwidthHigh BandwidthVery Low LatencyVery Low LatencyEase of UseEase of Use

High BandwidthHigh BandwidthVery Low LatencyVery Low LatencyEase of UseEase of Use

Very Low costVery Low costEase of UseEase of UseDynamic Attach-DetachDynamic Attach-DetachMultiple Peripherals Multiple Peripherals

Very Low costVery Low costEase of UseEase of UseDynamic Attach-DetachDynamic Attach-DetachMultiple Peripherals Multiple Peripherals

Low costLow costGuaranteed Latency Guaranteed Latency Higher BandwidthHigher BandwidthEase of UseEase of Use

Low costLow costGuaranteed Latency Guaranteed Latency Higher BandwidthHigher BandwidthEase of UseEase of Use

LOW SPEEDLOW SPEED10 - 100 Kb/s10 - 100 Kb/s

LOW SPEEDLOW SPEED10 - 100 Kb/s10 - 100 Kb/s

Interactive DevicesInteractive Devices(Game, VR)(Game, VR)

Interactive DevicesInteractive Devices(Game, VR)(Game, VR)

MEDIUM SPEEDMEDIUM SPEED500Kb/s - 10Mb/s500Kb/s - 10Mb/s

MEDIUM SPEEDMEDIUM SPEED500Kb/s - 10Mb/s500Kb/s - 10Mb/s

ISDN, POTS, PBX, ISDN, POTS, PBX, Audio, Imaging,Audio, Imaging,Bulk DevicesBulk Devices

ISDN, POTS, PBX, ISDN, POTS, PBX, Audio, Imaging,Audio, Imaging,Bulk DevicesBulk Devices

1394+1394+""firewire"firewire"1394+1394+

""firewire"firewire"

USB focus on

USB focus on LOW C

OST

LOW COST, , H

IGH VOLUME

HIGH VOLUME applic

ations!

applicatio

ns!

USB focus on

USB focus on LOW C

OST

LOW COST, , H

IGH VOLUME

HIGH VOLUME applic

ations!

applicatio

ns!

USB in 1996:USB in 1996:Initially introduced as an Initially introduced as an additional connector for new additional connector for new applications.applications.

USBUSB

PC Connectivity Vision


KeyboardKeyboard

MouseMouse

SerialSerialPortPort

ParallelParallelPortPort

SCSISCSIPortPort

Sound/GameSound/GamePortsPorts

GraphicsGraphicsPortPort

LANLAN ModemModem

GraphicsGraphicsPortPort

LANLAN

USB Future:USB Future:The PC evolves into a simpler, The PC evolves into a simpler, easier to use appliance.easier to use appliance. USBUSB USBUSB USBUSB

Telephony, Modem, Keyboard, Mouse,Game ports, Serial Telephony, Modem, Keyboard, Mouse,Game ports, Serial ports Device,Digital Audio, Printer, Scannerports Device,Digital Audio, Printer, Scanner

Hardware Overview...


USB

Topology Tiered Star (Distributes Connectivity Points) 127 logical connections (upto 5 meters per segment) Upto 6 tiers ...

Monitor

SpeakerPen Mouse

Kbd

Mic Phone

PC

HUBHUB

HOST/HUB

...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

Host

Root Hub

Device

DeviceDevice

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 ProcessEnumeration

Host Software is responsible for Device configuration

Host

Root Hub

Device

DeviceDevice

Device Device

HUB

Device

HUB

Universal Serial Bus, details Universal Serial Bus, details

Process of Configuration is accomplished via Control Transfers


Hardware Overview

- Bus transactions Speed: 12Mbps full-speed

1.5Mbps low-speed Isochronous and Asynchronous Media access controlled by host

- 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

- 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

- 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


- 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

DeviceDeviceDriverDriver FunctionFunction

USBUSBSoftwareSoftware

USB DeviceUSB DeviceI/FI/F

HostHostControllerController

USBUSBHardwareHardware

Function AbstractionFunction Abstraction

Device AbstractionDevice Abstraction

Physical ConnectPhysical Connect


PCPCDevice, like modem, Device, like modem, keyboard mouse, etckeyboard mouse, etc

Endpoint

Endpoint

Endpoint

USBTransfer types

...basics...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. 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

Frame = 1ms

printerprinter

ControControllControControll

USB Frame Modelexample

Stereo Audio

Telephony

SO

FS

OF

low-speed

IsochronouIsochronoussIsochronouIsochronouss

BulkBulkBulkBulk

InterruptInterruptInterruptInterrupt

...basics...basics

printerprinter

any LS device like keyboard, mouse,

etc.

any LS device like keyboard, mouse,

etc.

BulkBulkBulkBulk

max. 5mmax. 5m

CABLE connectorCABLE connector'upstream''upstream'

Connectors and CablesConnectors

4-Position with shielded housing Positive Retention Blind Mating Capabilities


Power pairPower pair

HOST PC / HUBHOST PC / HUB

CABLE connectorCABLE connector 'downstream''downstream'

HUB / DEVICEHUB / DEVICE

Differential Signal pairDifferential Signal pair

USB Hub FunctionPort Control

Connection detect

Port Enable/ Disable

Reset/ Resume Signaling

Data Switch Signal Regeneration

Robustness/ Recovery

Power Distribution

UpstreamConnectivity

HubHubRepeaterRepeater

DownstreamConnectivity

HubHubRepeaterRepeater

DisabledPort

EnabledPorts


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


Voltage Drop

Voltage drop per wire/connector: 0.125 VBudget for power switch: 0.100 V

Bus-PoweredBus-PoweredFunctionFunction

Bus-PoweredBus-PoweredHubHub

Host orHost or

Powered HubPowered Hub

4.65V (min) 4.40V (min)


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 rateUniversal Serial Bus 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


USB Connections and Terminations

D-

D+

R1

RR11 = 15K = 15K±5%±5%

RR22 = 1.5K = 1.5K±5%±5%

F.S./L.S. USBF.S./L.S. USBTransceiverTransceiver


(45Outputs)

Host or Hub Port

ZZOO = 90 = 90±15%±15%

5 Meters Max. 5 Meters Max.

F.S. USBF.S. USBTransceiverTransceiverF.S. USBF.S. USB

TransceiverTransceiver

(45Outputs)

Hub Port 0or

Full Speed Function

R1

R2

D-

D+

R1

RR11 = 15K = 15K±5%±5%

RR22 = 1.5K = 1.5K±5%±5%



(45Outputs)

Host or Hub Port

3 Meters Max. 3 Meters Max.

L.S. USBL.S. USBTransceiverTransceiverL.S. USBL.S. USB

TransceiverTransceiver

(45Outputs)

Low Speed FunctionR1

R2

D+

D-

D+

D-

TwistedTwisted Pair Shielded Pair Shielded


VCC

VCC

GND

GND

GND

GND

UnUntwisted, twisted, UnUnshieldedshielded

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-1 Transaction n-2 Transaction n-3

Transfer n

Transaction n-1



Host Software schedules and executes Transactions during 1ms Frames

Each Frame consists of several Transactions from different Transfers


Transfer n

Transaction n-1

1 ms Frame

Transaction n-1



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


Transfer n

Transaction n-1

Token Packet Data PacketHandshake

Packet

1ms Frame

Transaction n-1


Packet FormatsSync. Packet ID

DeviceAddress

ENDPNr

CRC EOP

8 bits 8 bits 7 bits 4 bits 5 bits 2 bits

Sync. Packet ID Data Field CRCCRC EOP

8 bits 8 bits 16 bits16 bits 2 bits0-1023 bytes

Sync. Packet ID EOP

8 bits 8 bits 2 bits

Token PacketToken Packet

Data PacketData Packet

Handshake/Low Speed Preamble

Sync. Packet ID Frame Number CRC EOP

8 bits 8 bits 11 bits 5 bits 2 bits

SOF Token PacketSOF Token Packet


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 HostData Packet from

USB Device to HostACK Packet from Host

ONE TRANSACTION


Sync EOP SyncPID

DataEOP Sync

PID

ACKEOP

PID

IN TokenData Packet (Payload)

Low Speed - Full Speed Transaction

Protocol overhead for FS and LS Transfers is 13 bytes

Payload for FS and LS is 8 bytesFS 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

Token Data Packet (8 bytes)Hand-

shake

one full speed transaction

Preamble

full

speed

low

speed

low speed

Token

full

speed

low

speed

Preamble Data Packet (8 bytes)Hand-

shake


USB 2.0 Technical Overview

Brad HoslerUSB Engineering ManagerIntel Corporation

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

USB 2.0: Conference Agenda

Architecture OverviewPeripheral Development EnablingUSB 2.0 Compliance and Logo ProgramUSB 2.0 Compliance Testing

Single Track:Topics for Everyone

Single Track:Topics for Everyone

Split Track: Focused TopicsSplit Track: Focused TopicsUSB 2.0: Technical Agenda

USB2 Specifications Electricals Protocol Hubs

Power ManagementHost Controller SpecCable TestingUSB “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

ArchitectureOverview

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

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

ContinuedContinued

System SWSystem SW

Client DriverClient Driver Client DriverClient Driver

USB 1.1 HubUSB 1.1 Hub

USB 1.1 USB 1.1 DeviceDevice


HS HubHS HubHS HubHS Hub

USB 1.1 HubUSB 1.1 Hub



HS DeviceHS DeviceHS DeviceHS Device

USB 2.0 HostUSB 2.0 HostControllerController

USB 2.0 HostUSB 2.0 HostControllerController

Full/Low SpeedFull/Low Speed

High Speed OnlyHigh Speed Only

(2 x 12Mb/s(2 x 12Mb/sCapacity)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 1.1 HCsHCsHigh-Speed ModeHigh-Speed Mode

(Enhanced Interface) USB HC(Enhanced Interface) USB HC

Port 1 Port 2

Port OwnerPort OwnerControl(s)Control(s)

Port 1 Port 2

Port Routing Logic

Port N

HC Control Logic/Data Buffering Enhanced HC Control LogicEnhanced Data Buffering

Port 2 Port N

Port N

USB 2.0 Hub

Hub controller same as USB1.1Routing logic connects device to appropriate path

High Speed onlyHigh Speed only

Full/LowFull/LowSpeedSpeed

Routing LogicRouting LogicRouting LogicRouting LogicPortPort PortPort

PortPort PortPort

TransactionTransactionTranslatorTranslator

TransactionTransactionTranslatorTranslator HS SignalHS Signal

RepeaterRepeaterHS SignalHS SignalRepeaterRepeater

HubHubControllerController

HubHubControllerController

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 BusHS Bus

Full Speed BusFull Speed Bus

uSOFuSOF

1ms1ms

uSOFuSOF uSOFuSOF uSOFuSOF uSOFuSOF uSOFuSOF uSOFuSOF uSOFuSOF uSOFuSOF

SOFSOF SOFSOF

SSSS

SS = Start SplitSS = Start Split

CSCS CSCS CSCS CSCS

125us125us

CS = Complete SplitCS = Complete Split

Demo: Full Speed Device

Show the split transactions

Show better performance behind USB 2.0hub 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

Documents

Interconnection Protocols Berk ÜSTÜNDAĞ Istanbul Technical University Computer Engineering Department [email protected]@cs.itu.edu.tr