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Newbie
Newbie
10,394 Views
Registered: ‎05-24-2013

TMDS from HDMI with GTX transceiver

Hi everybody,

 

We are trying to integrate and HDMI imput and output with a XC7K70T.

 

HDMI is mainly composed of 3 TMDS data pairs plus 1 TMDS clock pair

 

We were first thinking about using the TMDS I/O on the usual banks, but since we would like to process a full HD resolution which includes a 148.5MHz x 10 =1.485 Gb/s, we are thinking about using the GTX module.

 

Unfortunately, I don't really know if this could work.

TMDS is based on Vcc=3.3V and GXT is supplied with MGTAVCC=1V.

 

I found this app note http://www.xilinx.com/support/documentation/application_notes/xapp1077-phy-hdmi-rx-gtp.pdf

but I am struggling and can not find any with 7 series (GTX ion my case).

 

Any help would be appreciated.

 

Thank you

 

Best regards,

 

Maxime

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9 Replies
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Visitor
Visitor
9,739 Views
Registered: ‎11-10-2010

Re: TMDS from HDMI with GTX transceiver

Maxime,

 

I am considering doing the same thing - did you get this to work?

 

Thanks,

 

Jeff

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Visitor
Visitor
8,519 Views
Registered: ‎05-27-2014

Re: TMDS from HDMI with GTX transceiver

hi everybody,

I have the same question, any feedback for this topic?

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Moderator
Moderator
8,512 Views
Registered: ‎02-16-2010

Re: TMDS from HDMI with GTX transceiver

For 7-series GTX also MGTAVTT is 1.2V. This voltage source is used for Rx termination circuits. So, you could use the same calculations for 7-series GTX also.
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Scholar
Scholar
8,510 Views
Registered: ‎06-23-2013

Re: TMDS from HDMI with GTX transceiver

This document may help with connecting HDMI--which is CML--with the CML GTX transceivers:

http://pdfserv.maximintegrated.com/en/an/AN291.pdf

 

One of the biggest problems I see is that Xilinx says to capacitor couple the CML GTX transceivers, but the HDMI spec uses the DC coupling to do a monitor detect.  DC coupling between a 3.3V device and a 1.2V driver is not likely to work as you would like because the device is expecting a common mode voltage that will not be high enough during signalling.  Here is a TI part that does HDMI retiming using DC or AC coupling, with the note that AC coupling causes it to be a non-compliant source:

http://www.ti.com/lit/ds/symlink/ds34rt5110.pdf

 

Daniel

 

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Highlighted
7,407 Views
Registered: ‎11-20-2014

Re: TMDS from HDMI with GTX transceiver

Hi All,

 

I have used GTX to transmit the 1.485 GHz speed and got the 1080p60 video working fine on the HDMI connected to TV. I have build the FMC to HDMI connector with both TX & RX ports and also with the DDC lines for HDCP/DDC transactions. 

I am from India, if anybody interested contact me back for the FMC adapter at cost. 

 

Venkatesh K.

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Scholar
Scholar
6,528 Views
Registered: ‎12-07-2009

Re: TMDS from HDMI with GTX transceiver

I don't see any notable difference between Spartan-6 and a 7-series FPGA for this matter, except maybe the transceiver (GTP, GTX) primitive attributes and ports. But the transceiver connections and settings were not originally given with xapp1077 anyway...

 

I don't understand what's the problem. The electrical translation between GT <-> TMDS should not depend on the FPGA used... Or did I miss something ?

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Scholar
Scholar
6,524 Views
Registered: ‎06-23-2013

Re: TMDS from HDMI with GTX transceiver

Start a new thread.

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Highlighted
Scholar
Scholar
6,515 Views
Registered: ‎12-07-2009

Re: TMDS from HDMI with GTX transceiver

No need

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Visitor
Visitor
5,088 Views
Registered: ‎05-08-2014

Re: TMDS from HDMI with GTX transceiver

Venkatesh

 

I saw your post from last December and would be interested in finding out more information about your design and FMC board. Please contact me with the information

 

Mark

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