USB 3.1Universal Serial Bus.

Rainnyrainny.tu@gmail.com2016/08/31 update.

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Agenda• Introduction–What is USB?– History of USB.

• USB 3.1–Why is USB 3.1?– Design Goals.– Compare

• Type-C• Applications of Type-C• Compliance • Q&A

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What is USB?

• Universal Serial Bus. (USB)• User-friendly.• Plug-and-play way for device and host.• Do not need install device’s driver in

computer.• A standard bus to connector device to host

computer.

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History of USB

Jan, 1996

USB1.01.5Mbps

Low Speed

Sep, 1998

USB1.112Mbps

Full Speed

Apr, 2000

USB2.0480MbpsHi Speed

Nov, 2008

USB3.05Gbps

Super Speed

Jul, 2013

USB3.110Gbps

Super Speed +

Logo: USB-IF

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Why is USB 3.1?• USB / HDMI / Thunderbolt Data Rate

USB3.0 has lower rate of other usual device.

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Why is USB 3.1?• We have large data everyday.

Such as HDD, DVD, BR-DVD, HD TV, Ultra HD TV.• People demand higher performance between host

and peripheral.• Improve EMI performance & effect.

USB 3.0 will affect some device. (like wireless LAN Card)

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• Smart host and simple device.• Improve power management.• Ease of use .• Backward compatibility 2.0 at Type-A

connector.• Take advantage of USB 3.1 without change OS.

USB 3.1 Design Goals

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Compare - CableCharacteristic USB3.1 USB3.0 USB 2.0

Data Interface

Type-AConnector Pinout

Cable Length 1 Meter 3 Meter 5 Meter

PCB Trace Length 8 Inch (20.32cm) 12 Inch (30.48cm)

• About Cable.

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Compare – Data Rate

Characteristic USB3.1 USB3.0 USB 2.0

Speed SuperSpeed Plus SuperSpeed HiSpeed

Data Rate 10 Gbps (Gen 2) 5.0 Gbps (Gen 1) 480Mbps

Encoded Mode 128b/132b 8b/10b 8b/10b

Encoded Loss -3.03% (96.97%) -20% (80%) -20% (80%)

Actual Rate10Gb/s * (128/132)

= 9.697Gb/s= 1.21GB/s

5Gb/s * (8/10)= 4Gb/s

= 500MB/s

480Mb/s * (8/10)= 384Mb/s= 48MB/s

• About Data Rate.

* USB3.1 (Gen 2) real transfer speed is up to x2.4 of USB3.0.

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Compare - Connector• Review USB 2.0 & USB 3.0 connector.

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Type-C• About USB 3.1 connector• Type-A : the same as USB 3.0 Type A.

• Type-C : Release by USB.org in 2015 April.USB.org want to let Type C become the common connector of mobile devices.

• Existing USB connector is difficult to use.New connector is no directionality.

• Backward compatibility.

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• Plug-unplug over 10,000 times.• Support large power charging. (According to PD spec.)

Supply peripheral or mobile device with up to 100W.Need to add ICs to control.

• Increased data channels. (Ideal)Two pairs of Tx/Rx signal paths.Provide total bandwidth of 20Gbps.

• Thunderbolt 3 connector.(release: June, 2015)Data rate: 40Gb/s ~= 5GB/s

Type-C

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• Let’s see how does it look like.

Type-C

Male FemalePhoto by rainny.

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Type-C• USB Type-C Pin defined.

Fig 2-1/2-2: USB3.1 spec.

- Receptacle Configuration.

- Plug Configuration. (for cable and device)

- Plug can insert into receptacle. Also can rotate 180˚.

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• Let’s check the receptacle side of system or device.Type-C

• D+/D-: signal path for USB2 only.• Vbus/GND: Power for USB.

Also implement large power charging. Can deliver up to 100W.

• Tx1/2, Rx1/2: 2 channels of SuperSpeed+ data links.• CC1/CC2: Configuration channel. Detect connections and

interface.• SBU1/ 2: Sideband use pins. Non-USB signals.

Usually used in Audio mode.

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Applications of Type-C• ex. USB Type-C to DisplayPort

• DisplayPort can use all of the high speed paths to deliver.• Type-C side can be reversible.• Also can support HDMI, DVI, VGA cable.

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Compliance• Updating compliance plans & specs.• Host/ Devices will be test for:– Support USB 2.0 speeds.– Meet Superspeed(Gen1) requirements.– Meet Superspeed+(Gen2) requirements.

• USB 3.1 Compliance Requirement– New electrical test for physical layer.– New cable and connector test. USB 3.1 Signal

Function Validation of Key

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• Compare with the basic spec.

Compliance

Table 6-17/ 6-19: USB3.1 spec.

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• Eye Diagram.Compliance

Eye Diagram: USB3.1 spec.

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Conclusion• High performance.

USB 3.1 provide data rate up to 10Gbps, 2x of USB3.0.

• Conveniently.Standard connector, has no directionality.

• Less lose of encoder. Efficiency is improved up.• No driver software changes required.• EMI performance upgrade.

Improved shielding and grounding of connector.

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Thanks.

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Q & A