HDMI Madhav Achar, Patrick D’Agostino, and Arthur Rajala EECS 373 March 2014 University of Michigan 1.

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

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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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