azonenberg changed the topic of ##openfpga to: Open source tools for FPGAs, CPLDs, etc. Silicon RE, bitfile RE, synthesis, place-and-route, and JTAG are all on topic. Channel logs: https://libera.irclog.whitequark.org/~h~openfpga
<markus-zzz>
unfortunately my problem that the upper 8 data bits are occasional garbage remains.
<markus-zzz>
of course if it actually works out as intended having all the interface flops in the io-cells is much than risking them ending up in fabric so it is a good change anyway.
<markus-zzz>
I also had a quick look at the sdram pcb layout of the ulx3s and as far as I can see the traces for d[7:0] and d[15:8] are pretty symmetrical so I would expect there to be no major difference in delays. That is if I understood the suggestion correctly that the pcb would be the issue.