HDMI directly into FPGA

[Yaacov]

Hello,

I have worked with HDMI on the Zybo Z7 which features a TMDS141 TMDS signal repeater on the HDMI IN port. However, the Arty Z7 has the TMDS lines going directly from the HDMI IN to the FPGA. I'm planning on designing a custom FPGA board and would really appreciate it if you could share your design considerations.

Besides for the obvious advantage of protecting the FPGA, in your experience, does the repeater provide any other significant benefit ?
Are there certain HDMI sources that will only work with the Zybo but not the Arty ?

Thanks,
Yaacov   

 

[elodg]

Carefully evaluate your system requirements (resolution, link rate) and do board-level simulation on the TMDS signals. FPGA user I/O pins have considerable capacitance and might close your signal eye too much.

Buffers like the TMDS141 help with decoupling cable segment from the PCB, making longer PCB traces possible. Our development boards are not HDMI-certified, but buffers might make passing electrical certification easier.