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stgateizo
Voyager
Voyager
280 Views
Registered: ‎10-07-2016

HDMI 2.0 Tx Subsystem: Support of non-CEA conform output timings possible?

Dear colleagues,

Maybe somebody can help me to clearify a question regarding the HDMI2.0 Tx Subsystem form Xilinx.
The HDMI example design from Xilinx supports CEA-conform output timings, which are defined by a VIC (Video Identifier Code).

Question:
Does the HDMI2.0 Tx Subsysten also support custom timings, which are not supported by the CEA?

For example, if I would like to output a 1920x2160@60Hz timing over HDMI, would this be possible to achieve this ?
If so, what do I have to do to achieve this?

Kind regards

stgateizo

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8 Replies
watari
Teacher
Teacher
248 Views
Registered: ‎06-16-2013

Hi @stgateizo 

 

>For example, if I would like to output a 1920x2160@60Hz timing over HDMI, would this be possible to achieve this ?

Yes.

Would you refer VESA CVT to decide video timing ?

 

Best regards,

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stgateizo
Voyager
Voyager
210 Views
Registered: ‎10-07-2016

Hi watari,

> Yes.
Okay can you explain how to do it?

> Would you refer VESA CVT to decide video timing ?
I want to use a custom timing => Not Vesa CVT compliant...

Regards
stgateizo

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watari
Teacher
Teacher
189 Views
Registered: ‎06-16-2013

Hi @stgateizo 

 

I suggest you to refer VESA CVT formula, even if you want to use custom video timing.

It makes sense to refer it.

Would you refer it ?

 

Best regards,

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stgateizo
Voyager
Voyager
169 Views
Registered: ‎10-07-2016

Hello watari,

It is not of interrest if it is a VESA CVT or a CEA timing !

I need the information how to apply a custom timing by using the HDMI Tx Subsystem !

Kind regards

stgateizo

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watari
Teacher
Teacher
156 Views
Registered: ‎06-16-2013

Hi @stgateizo 

 

Would you refer AR #68227 ?

 

https://www.xilinx.com/support/answers/68227.html

 

Best regards,

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stgateizo
Voyager
Voyager
148 Views
Registered: ‎10-07-2016

Hello watari,

thank you for this information. AR #68227 is more or less describing what I'm looking for.

If I understand it correct, you have to add a custom timing before you compile the code. But I'm looking for a way to programm a custom timing during runtime, while the custom timing is not known at compile time. I get the timing information during runtime. So I cannot add the timing to teh timing table as described in AR #668227. Is this also anyhow supported?

Best regards

stgateizo

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stgateizo
Voyager
Voyager
143 Views
Registered: ‎10-07-2016

Hi watari,

I think the main problem to achieve this is the following call:

XV_HdmiTxSs_SetStream(&HdmiTxSs, XVIDC_VM_3840x2160_60_P, XVIDC_CSF_RGB, XVIDC_BPC_8, NULL);

The function above contains the video mode parameter XVIDC_VM_3840x2160_60_P,  which is used to point to the corrsponding entry in the timing table.

If I only get the timing information during runtime, and if i want to program this timing during runtime, I cannot use the function above.

When I go deeper in the driver function XV_HdmiTxSs_SetStream(), I will find the following code:

Pic.PNG

If I'm correct, the TimingPtr points to the timing information in the timing table. If so, I could manipulate the TimingPtr, so that it is pointing to a variable of type XVidC_VideoTiming, which could contain a custom timing, and which could be loaded upfront. But this requires a change in the driver file...

Is there a better way to do it?

Kind regards

stgateizo

 

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stgateizo
Voyager
Voyager
139 Views
Registered: ‎10-07-2016

Hi watari,

there is maybe a better way to do it. If it would be possible to manipulate the timing table below during runtime, it could be achieved, wihtout chaning the driver files...

but the structure is defined as const. I'm not sure if I can change it...

Pic1.PNG

 

regards

stgateizo

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