HDMI

Madhav Achar, Patrick D’Agostino, and Arthur Rajala

EECS 373March 2014

University of Michigan1

Purpose

• Protected data transmission

• Real world embedded systems

• Future coursework: 473

2http://store.jvc.com/images/product/HDMI-HDMIMINI.JPG

What is HDMI?

● High Definition Multimedia Interface○ Audio/video transmission

• Video uncompressed

• Audio compressed or uncompressed

● By 2013, over 3 billion HDMI devices sold○ Surpassed DVI in 2008[1]

● Possible alternative for 373 projects○ No HDMI port on Smartfusion boards○ Raspberry Pi, Arduino TRE, BeagleBoard

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Technical Specifications

HDMI 1.0[2]

December 9, 2002

• 5GB/s, 3.95GB/s without overhead

• <= 1080p @ 60Hz

• 8 audio channels

• 192 kHz audio sampling frequency

• Supports HDCP

• Same video format as DVI

HDMI 2.0[3]

September 4, 2013

• 18.8 GB/s, 14.4 GB/s without overhead

• <= 2160p @ 60Hz● 32 audio channels● 1536 kHz audio

sampling frequency● Supports HDCP● Backwards

compatible connector 4

High-bandwidth Digital Content Protection

(HDCP)1.Authentication of receiver

a. Shared secret session keyb. Authenticate any downstream receivers

c. Recheck every 128 video frames[4]

2.Encryption of data streama. Pixels XOR-ed with a changing 24 bit number

3.Key revocationa. Checks for compromised device

5

Pin Connections

Pins 1-9: 3 TMDS Channels

Pins 10-12: TMDS ClockPin 13: CECPin 14: ARC/HEC (1.4)Pin 15-16: DDCPin 17: Data shieldPin 18: Power supply (+5V)

Pin 19: Hot plug detecthttp://www.hdmi.org/installers/insidehdmicable.aspx

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Display Data Channel (DDC)

• HDCP authentication

• Automatic Device Configurationo Video/audio format on

receiverso Precise latency data to

keep synchronization

• Unidirectional I2C buso 100 kbit/s minimum http://www.hdmi.org/installers/insidehdmicable.aspx

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Transition Minimized Differential Signaling

(TMDS)● Interleaves video,

audio, auxiliary data

• 3 transmission periodso Video datao Data islando Control

• 8b/10b encoding using bitflipping, XOR/XNOR

• Audio clock recovery http://www.hdmi.org/installers/insidehdmicable.aspx

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Consumer Electronics Control (CEC)

• Controls up to 15connected devices○ Used for One Touch Play,

System Standby, Menucontrol, etc

● One-wire bidirectional bus based on AV.link[5]

○ Open collector○ Value determined by low period

http://www.hdmi.org/installers/insidehdmicable.aspx

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CEC Example

http://www.cypeurope.com/store/store/app/product/CPRO-8MCEC/HDMI-1-to-8-Distribution-Amplifier-with-CEC-Function 10

Example Project Using HDMI

http://blog.parts-people.com/2012/12/20/mobile-raspberry-pi-computer-build-your-own-portable-rpi-to-go/ 11

What are the alternatives?

VGA DVI HDMI DisplayPort

Pros • No strict resolution limit• 2048 x 1536 standard cable limitation

• Same format as HDMI• 1080p

• Video and audio• 2160p (2.0),1080p (1.0)• 30 fps

• 2160p• Audio and video● 60 fps

Cons • Only Video• Analog signal interference

• Only video • Fees • Ports only appear on computers

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Cables and Cost

• Cost to the manufacturero Large manufacturers: $10,000 per year

• Additional $0.15 per device

• Reduced to $0.05 if HDMI logo used

• Reduced to $0.04 if HDCP implementedo Small volume manufacturers: smaller yearly

fee, pay more per device

• Types of Cableso Standard (Type I) cables tested to 75MHz, or

up to 2.25 Gb/s (720p/1080i)o High Speed (Type II) cables tested to

340MHz, or 10.2 Gb/s (2560x1600) 13

Conclusion

• Powerful interface for multimedia contento Audio, video, device controlo High bandwidtho Automatic configurationo Data protection

• Popular, standard in embedded systemso Need separate board for 373o Used for other EECS courses

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Sources1. "HDMI Specification Marks 10-Year Milestone as De-Facto Standard for HD Connectivity". HDMI Licensing,

LLC. 2013-01-08. Retrieved 2013-01-10.

2. http://www.hdmi.org/manufacturer/hdmi_1_4/hdmi_1_4_faq.aspx

3. http://www.hdmi.org/manufacturer/hdmi_2_0/hdmi_2_0_faq.aspx

4. http://www.digital-cp.com/files/documents/04A897FD-FEF1-0EEE-CDBB649127F79525/HDCP_deciphered_070808.pdf

5. HDMI Specification Version 1.3a, Supplement 1: Consumer Electronics Control (CEC)

6. http://www.hdmi.org/installers/insidehdmicable.aspx

7. http://www.hdmi.org/pdf/whitepaper/DesigningCECintoYourNextHDMIProduct.pdf

8. http://www.digital-cp.com/files/static_page_files/F3FDE47C-1A4B-B294-D0802DFEF646E602/HDCP%20on%20HDMI%20Specification%20Rev2_2_Final1.pdf

9. http://www.hdmi.org/manufacturer/hdmi_2_0/index.aspx

10. http://web.archive.org/web/20080211111003/http://www.hdmi.org/press/pr/pr_20060622.aspxhttp://newslittle.com/wp-content/uploads/2013/09/HDMI-logo_black-1600px_610x130.png

11. http://www.aes-media.org/sections/uk/Conf2011/Presentation_PDFs/14%20-%20john%20dawson%20-%20Audio%20Transport%20over%20HDMI%20-%20AES%202011.pdf

12. http://www.cec-o-matic.com/index.php

13. http://store.jvc.com/images/product/HDMI-HDMIMINI.JPG

14. http://www.hdmi.org/images/consumers/Home_Theater_1.jpg

15. http://www.sz-wholesaler.com/userimg/432/434sw1/hdmi-projector-hd66-89.jpg

16. http://cellphones.techfresh.net/wp-content/uploads/2009/05/hitachi-hd-woo-cellphone.jpg

17. https://lh3.ggpht.com/_OKvjOZi2mHU/TOuuorjHrrI/AAAAAAAAAMc/30HxOU2-FmA/s1600/atmdeath.jpg

18. http://www.techfuels.com/attachment.php?s=c1c80c743f91720f2f7a5a7bcf44a7da&attachmentid=23148&d=1297838473

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