FMC Connector configuring Single-ended or differential pair pins on Genesys 2 Kintex-7 FPGA Development Board

[tshen46]

 

Hi, I am looking to purchase the Genesys 2 Kintex-7 FPGA Development Board for my project design because I noticed that the FMC connector on the FPGA board is at size of 400 pin HPC. And some datasheets said it contains 160 user-defined pins on the FMC connector. I am not sure if these 160 user-defined pins are all needed to be configured on 80 differential pairs. or I can configure them as 160 single-ended pins? Since it is not obviously mentioned in the document, I am quite looking forward to it behaving like 160 single-ended pins. Could you please look that up for me?

[asmi]

Any differential pair can technically be used as two independent single-ended connections. The only possible problem is a cross-talk across two traces of a pair. So as long as your edges are not very fast, you should be able to get away with it.

[tshen46]

On 5/23/2024 at 8:48 PM, asmi said:

Any differential pair can technically be used as two independent single-ended connections. The only possible problem is a cross-talk across two traces of a pair. So as long as your edges are not very fast, you should be able to get away with it.

I am also curious about FMC LPC. I have already implemented a project with up to 20 MHZ on a Xilinx spartan-7 FPGA board. So essentially, LPC might also have the same type of cross-talk issues, but since it can FMC LPC can push up to 20 MHz at data transmission, which means this FMC HPC on Genesys 2 Kintex-7 FPGA Development Board can work up to 20 MHz at data transmission. Is my understanding correct?

[asmi]

8 hours ago, tshen46 said:

I am also curious about FMC LPC. I have already implemented a project with up to 20 MHZ on a Xilinx spartan-7 FPGA board. So essentially, LPC might also have the same type of cross-talk issues, but since it can FMC LPC can push up to 20 MHz at data transmission, which means this FMC HPC on Genesys 2 Kintex-7 FPGA Development Board can work up to 20 MHz at data transmission. Is my understanding correct?

20 MHz at typical for this frequency edge rates should be no problem.