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ywguo Community Fellow Offline Posts: 943 Shanghai, PRC	Does HDMI require patent fee? Apr 13^th, 2006, 8:11am Hello, HDMI is a popular interface now. Does HDMI require patent fee? I mean that if one design and sell HDMI product or IP, is the patent fee required? Best regard, Yawei
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Paul Community Fellow Offline Posts: 351 Switzerland	Re: Does HDMI require patent fee? Reply #1 - Apr 13^th, 2006, 8:58am Hi Yawei, Yes it is... :( More information on this page: http://www.hdmi.org/manufacturer/terms.asp Paul
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gitarrelieber Junior Member Offline Posts: 12 Villach	Re: Does HDMI require patent fee? Reply #2 - Apr 18^th, 2006, 6:21am I think HDMI is still a very primitive serial link in comparison to other standard like SONET, 10GbE, SATA. For one thing, it does not contain Error Correction. The data are not scrambled to increase randomness.
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Paul

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Posts: 351
Switzerland

Re: Does HDMI require patent fee?
Reply #3 - Apr 19^th, 2006, 12:06am

Hi,

I believe there are good reasons not to include these features and I don't think the mentioned protocols are comparable. SONET is a long-distance communication standard, 10GbE shoots for comparable applications (while also targeting the LAN market somehow) and SATA is a storage interface. More appropriate comparison would be USB or FireWire, I believe.

I believe HDMI uses minimum transition codes to keep the signal bandwidth requirements as low as possible. Based on this, scrambling would be a nonsense because it would destroy the code's frequency domain properties. The idea of HDMI is to achieve maximum distance (15m) over copper to keep the cable prices within reasonable bounds. I believe none of the mentioned protocols is able to achieve operation over comparable distances on copper links (possibly 10GbE would?).

Error correction, scrambling and data encoding always relate to tradeoffs in terms of bandwidth and/or latency. In the case of a DVD-TV link, you certainly don't want to spend money on optical fibers, so bandwidth is constrained. On the other hand, you want your image to stop right there when you hit the pause button, so latency is critical too. In that sense, I believe the HDMI spec may be a good solution to the problem. In comparison, SONET and 10GbE are not latency sensitive, while SATA could more easily accept compromise on the maximum distance during the specification process to alleviate bandwidth constraints.

Paul

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jbdavid

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Posts: 378
Silicon Valley

Re: Does HDMI require patent fee?
Reply #4 - Apr 21^st, 2006, 1:03am

while your at it you should definitely consider USB 2.0 , pci-X and FBD (Fully Buffered DIMM) ..

all of these are serial links in the 2-5 (maybe 10?) Gb/s rate..

10G-BT (the 10G Ethernet over copper) is 4x3Gp/s BOTH DIRECTIONS over 4 pairs (Cat-6)
10G-LR/10G-SR are OPTICAL on Single mode fiber..
10G-LRM is Optical on MM Fiber
10G-LX4 is 4x3Gb on MM Fiber using WDM ..

FBDIMM and PCI is targeted for "on the mother board" memory and peripheral interface respectively..
SATA is similar but (typically) for "in chassis" comms.

HDMI is targeted at computer to Display Device (essentialy one way)

the biggest difference in these is the overhead / data stream formatting that works best with the particular devices
distances and communication needs..

reality is you only NEED HDMI if you NEED to put "HDMI supported" on your package..
and to be able to do that you will not only need to license IP, but pass interop testing with other vendors..
(I probably simplify this too much.. for details go to the web page .. I didn't but just make assumptions based
on other standards groups.. but at least I tell you this.. )

Otherwise you can buy LVDS chips from National and "roll your own" serial interface.

jbd

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jbdavid
Mixed Signal Design Verification

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ywguo Community Fellow Offline Posts: 943 Shanghai, PRC	Re: Does HDMI require patent fee? Reply #5 - Apr 24^th, 2006, 1:25am Hi, Thanks for your comments. They throw light on some very insteresting factors. Best regards,
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