Display interface using SN75DP130 or SN75DP126

Hi Roy,

I'm not sure what you are trying to do.
DP first reads display information using AUX channel, then, sends video to a display.
You can't read from a DP output port, This DP output port is the one that decides to send video, using an FPGA you may implement a DP sink and receiver the video.
Using an FPGA you can read the display information located en EDID registers.

Regards

Hi Moises sorry if i was a bit vague,

What i am trying to accomplish is to read the display output data from something like a computer, this is the data that normally goes to your screen. what i want to be able to do is i want to be able to be reading Displayport output and also HDMI output. But i want to use a displayport connector, so i need Dual mode displayport IC right? to be able to read both Displayport information, or if i use a displayport to HDMI passive converter, be able to read the HDMI data. After i have read this , i want to be able to read this data and do somethign with it in on a FPGA.

so i was wondering if one of those IC's was what i needed. Or am i completly wrong? it were a couple of long days and i am a little bit tired haha.

Hi Roy,

In these video protocols, you can't read the video from computer, you receive the video from the computer.
The difference is: from the FPGA perspective you are not requesting the data(reading) you are just receiving what the computer sends.
To receive data from computer, you have to implement EDID registers in FPGA, so your computer will think this is a display and send data.

First make sure your computer is DP++(For HDMI too)
Then, you have to implement AUX(DP) and DDC(HDMI) interfaces, this is in order to computer can read Display capabilities.
Finally implement DP and HDMI receivers, here since your FPGA may receive AC signals, you don't need a level translator.
So, you may use DP130 but you need to implement DP-HDMI ADAPTOR ID BUFFER, or use DP126 which has everything you need, but you would have to add termination resistors on HDMI port.

Regards

Hello, 

Sorry english is not my native language, so i am aware that you receive not read, bad choice of word from me. Thanks for the help!

But just to be clear, i want from my computer to send from the Displayport output OR from the HDMI output. And than want with the FPGA and DP130/DP126 with only one DP++ input to be able to receive both of those displaydata. (depending on which one is connected). So i can use from HDMI(from computer) to DP(FPGA) converter to also receive the signals with the DP126?

what i get from your answer is that if u connect a displayport tx on a displayport++ rx, that that won't work?