Honored Contributor
Honored ContributorI can't say for the specific case. Note that one other case I've seen RAMs shared is when it's two single port RAMs can be merged into one dual-port RAM block. In that case though, I'm pretty sure the fitter has complete flexibility to merge and unmerge them to meet timing, so I've never seen it cause timing issues. (I t hink they maintain seperate logical names too, so you wouldn't even notice it like you are, so that's probably not it).
There is no "divider RAM" merging algorithm, so you'll need to dig in and see what exactly is being merged and try to figure out why, or see if you can manually prevent it from occurring. Were you able to try the partitions? Also, are you sure the merging is what's causing worse timing? (That is probably hard to diagnose without stopping it from happening and comparing).
