Zybo Board : Pmod to I/O

[Mendeln]

Hello everyone,

 

I would like to use all I/O from Pmod connectors (6x8, 48 I/O) but I am not sure that's possible. Actually, I am wondering if we can program the FPGA in order to have 8 single-ended signals for High-Speed Pmods. I think it can work like this. However, the crosstalk issue is mentionned in the reference manual and I don't know how far it can work without problem.

 

Otherwise, I am not focused only on that board. I am looking for one which is able to handle a screen, a mouse, a keyboard, a printer and 45-50 digital I/O in order to make an embedded computer. If someone has any suggestion, I would appreciate. 

 

Thanks

Mendeln

[Mendeln]

I have found the answer to my question here : 

 

http://electronics.stackexchange.com/questions/102161/drawbacks-of-using-single-ended-communication-over-differential-pairs

 

Hope this will help. 

 

Mendeln

[sbobrowicz]

Glad you found an answer, I'd like to add one thing though: Pmods JA-JE are connected to the FPGA fabric, but Pmod JF is connected to the MIO bus of the Processing system. This means that the pins are not accessible from the FPGA for general purpose, but instead connected to the processor peripherals, such as the GPIO controller. This means there are only 40 externally routed I/Os connected to the FPGA, and 8 additional I/Os that can be controlled from the Zynq processor.