Using ARTY A7 with PMOD RS232

[Mukta]

Hello,

Can I connect high speed pmod connector present on cora z7-10 FPGA board to PMOD RS232 converter board? Since high speed pmod has differential I/O pins.

[artvvb]

Yes, the high speed Pmod connector pins can be used for single-ended signals. Section 12.1 of the Cora's reference manual has a little more information on this: https://digilent.com/reference/programmable-logic/cora-z7/reference-manual#high-speed_pmods

Thanks,

Arthur

[Mukta]

It says other pair of differential pin should be made ground to make other pin of pair as single ended. But in case I connect PMOD RS232 directly to high speed pmod, does that work? 

[artvvb]

The grounding scheme is suggested to reduce crosstalk that might appear with higher speed signals than you would be using with the Pmod RS232. I don't have numbers on when the crosstalk may become an issue, but don't expect that there would be issues with connecting the Pmod directly - I ran a Pmod VGA with an ~25 MHz pixel clock off of the Cora's Pmod ports successfully a couple of years ago.

[mwagner]

25MHz pixel clock is not that high, right? What would be the highest pixel clock which can be used together with the Arty and these Ports?