Hi Guys, I've got an V2PRO RPM that uses only FFs in slices. How do I prevent ISE7.1 from placing the RPM so that it straddles a BlockRAM/Mulitplier column? When this straddling happens, the routing across the column takes a 300ps hit that I'd rather not have. I've looked at RPM_GRID; it doesn't seem to help. TIA, Syms.
RPM.
Jan 23, 2006
2 Replies
Either place it with an RLOC_ORIGIN, or use an area contraint to restrict it to certain columns.
You have to be careful of that straddling for V4 if you have memories in your RPM, the mapper has a bug in it where it counts the BRAM/DSP48 column when figuring out if the placement puts a memory column of your RPM into a non-memory slice column.
Many thanks, Syms.
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