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Topic: HDMI port can be used for INPUT? (Read 563 times) previous topic - next topic

pk14225

Hello, can the mini-HDMI port on the Vidor4000 be used as an HDMI input, or is it only an output?  If it can be an input, is there any software support for this and/or would it be a horrifically difficult software development to develop the ability to do a frame-capture from an incoming HDMI stream?  Any advice appreciated.


Limba

In theory: yes
Is there limitations: YES
Is there premade block in repository: I think No
Is there IP in opencores for it: No


Few questions:
Does source support uncrypted video signal?
What is max resolution + refreshrate?

Basically you have to connect received pixel clock to PLL and create receiving clock from it. It's little harder because this Cyclone 10 LP don't have xcvr blocks that will sync to receiving signal after it get bit sync.
After that you have to sync to receiving signal frame structure.

Still intrested. Here is some appnote for Spartan6 (Xilinx) device for HDMI 2x2 mux
https://www.xilinx.com/support/documentation/application_notes/xapp495_S6TMDS_Video_Interface.pdf
Here is some info from Intel/Altera (Ready IP uses xcvr, Cyclone 10 GX)
https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/ug/ug_hdmi.pdf

Recommend to start something little easier or try to get somebody who can design IP blocks. That HDMI receiving is not easy task for Cyclone 10 LP. At least there are some resolution limitations. you can see needed clocks from xilinx appnote.

DarioPennisi

hi,
while pins can be used as inputs the issue is that clock signal is not connected to dedicated clock pins so the result is that you can't reliably connect that to a PLL, which is required to multiply the clock x10 to deserialize data.
actually you may try connecting through the camera input but that only has 2 pairs so you won't be able to get full colour. note also that in order for HDMI to work you have to provide an I2C slave to provide descriptors for the source to understand which is the max resolution being supported.

Limba

Forgot to check that from schematics. I was assuming that it was connected to clock pins.

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