Pin function of CW305 20-pin connector

Hi all,

I’m using the CW305 Artix target for Power-SC measurement very successfully so far.

As my setup is becoming stable, I’d like to get rid of the Jumper Cables connected to JP3, that connect a necessary control board to the CW305 FPGA. This is where the 20-pin connector came to my mind.

I can see in the schematic that many pins of this connector are routed to FPGA-pads, so they are directly usable for communication with the FPGA. But two pins on the 20-pin connector remain unconnected, except for the ESD protection.

In particular, I refer to PMOSI and PRST. With these Pins connected to the FPGA, I could route my SPI-connection “properly” across the 20-pin connector.

I’ll probably be able to just use the remaining, connected, pins of the 20-pin connector for my communication interface instead. But I was wondering, if there is a reason, why these two pins are not connected to the FPGA on the PCB? I might have overlooked something!

Best regards

Edit: Typos

I think it was just something that was overlooked during the design of the 305 board.


1 Like

It would seem you are not the one that has overlooked something :wink:

It was possibly routing difficulty of getting those pins out wasn’t worth it, was a long time ago now! But to reduce noise etc the routing gives preference to avoiding crossing some of the power domains with digital signals - normally wouldn’t be an issue on an FPGA board, but as this one is designed to avoid as much cross-contamination as possible it differs…