May 16, 2000 2

USB 2.0 Technical Overview

USB 2.0 Technical Overview

Brad HoslerBrad Hosler

USB Engineering ManagerUSB Engineering Manager

Intel CorporationIntel Corporation

May 16, 2000 3

Conference GoalConference Goal

Provide you with the information youProvide you with the information youneed to build USB 2.0 productsneed to build USB 2.0 products– USB 2.0 technical detailsUSB 2.0 technical details– USB 2.0 InfrastructureUSB 2.0 Infrastructure– Building USB 2.0 devicesBuilding USB 2.0 devices– USB 2.0 Building BlocksUSB 2.0 Building Blocks

May 16, 2000 4

USB 2.0: What Is It?USB 2.0: What Is It?

Same host/device modelSame host/device model– Host is in chargeHost is in charge– Devices are inexpensiveDevices are inexpensive

Same basic protocolSame basic protocol– Token, data, handshakeToken, data, handshake

Same device frameworkSame device framework– DescriptorsDescriptors

Same software interfacesSame software interfaces– USBDIUSBDI

May 16, 2000 5

USB 2.0: What Is It?USB 2.0: What Is It?

Same power distribution and consumptionSame power distribution and consumption– 500ua suspend, 100ma unconfigured,500ua suspend, 100ma unconfigured,

500ma configured500ma configured Same power management featuresSame power management features

– Suspend/resume model unchangedSuspend/resume model unchanged Same topology managementSame topology management

– Hub features to handle connect, disconnect,Hub features to handle connect, disconnect,enable, disable, …enable, disable, …

Same cables and connectorsSame cables and connectors

ContinuedContinued

May 16, 2000 6

No changes for No changes for these SW piecesthese SW pieces

New development New development work for Host work for Host Controller Driver Controller Driver and Hub Driverand Hub Driver

USB 2.0 Software StackUSB 2.0 Software Stack

No Changes to Existing InfrastructureNo Changes to Existing Infrastructure

Areas Needing Development WorkAreas Needing Development Work

Host ControllerDriver

Host ControllerDriver

Bus DriverBus Driver

Device DriversDevice Drivers

ApplicationsApplications

Hub DriverHub Driver

May 16, 2000 7

USB 2.0: What Changed??USB 2.0: What Changed??

Low level electricals for High Speed (HS) Low level electricals for High Speed (HS) signalingsignaling– Much higher bit rate (480Mb/s) requires new Much higher bit rate (480Mb/s) requires new

transmitter/receiver transmitter/receiver Hub changes for backward compatibilityHub changes for backward compatibility

– Features limit bandwidth impact of Full Speed (FS)Features limit bandwidth impact of Full Speed (FS)and Low Speed (LS) devices on HS devicesand Low Speed (LS) devices on HS devices

– FS/LS devices consume a bit-rate equivalentFS/LS devices consume a bit-rate equivalentof HS bandwidthof HS bandwidth 6Mb/s conferencing camera consumes 50% (6 / 12) of FS 6Mb/s conferencing camera consumes 50% (6 / 12) of FS

bus, but only ~2% (6 / 480) of HS busbus, but only ~2% (6 / 480) of HS bus

May 16, 2000 8

System SWSystem SW

Client DriverClient Driver Client DriverClient Driver

USB 1.1 HubUSB 1.1 Hub

USB 1.1 USB 1.1 DeviceDevice

USB 1.1 USB 1.1 DeviceDevice

HS HubHS HubHS HubHS Hub

USB 1.1 HubUSB 1.1 Hub

USB 1.1 USB 1.1 DeviceDevice

USB 1.1 USB 1.1 DeviceDevice

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 TopologySample USB 2.0 Topology

Hub provides high-speed expansion (ala USB 1.1 hub)Hub provides high-speed expansion (ala USB 1.1 hub) Hub provides additional Full/Low speed bus(es)Hub provides additional Full/Low speed bus(es)

May 16, 2000 9

USB 2.0: Conference AgendaUSB 2.0: Conference Agenda

USB 2.0 specificationUSB 2.0 specification– Low Level Electricals and ProtocolLow Level Electricals and Protocol– Data transfers, framework, transaction protocolData transfers, framework, transaction protocol– USB 2.0 hubsUSB 2.0 hubs

Peripheral EnablingPeripheral Enabling USB 2.0 Compliance ProgramUSB 2.0 Compliance Program

Day OneDay One

May 16, 2000 10

Day Two: Single TrackDay Two: Single Track

USB 2.0: Technical AgendaUSB 2.0: Technical Agenda

KeynotesKeynotes– Nathan BrookwoodNathan Brookwood– Bill MachroneBill Machrone

Software RoadmapSoftware Roadmap

May 16, 2000 11

Day Two: Dual TracksDay Two: Dual Tracks

USB 2.0: Technical AgendaUSB 2.0: Technical Agenda

Specification DetailsSpecification Details– Electrical and HubElectrical and Hub– Isochrony and SynchronizationIsochrony and Synchronization

Building USB 2.0 ProductsBuilding USB 2.0 Products– USB 2.0 Peripheral Design OptionsUSB 2.0 Peripheral Design Options– Production TestingProduction Testing– Platform Design ConsiderationsPlatform Design Considerations– BIOSBIOS– Power ManagementPower Management