Pblock resources (Slice) could not be used in V5 P&R
I'm using the V5 Lx330(ff1760) in my design.
I've drawed some Pblocks for some of my design's sub-modules. My problematic pblocks include the slices which are from SLICE_X208Yzz to SLICE_X215Yzz. (i.e. all the slices on rigth of the IOB resource as shown in the plan-ahead for the LX330FF1760; "zz" is any number and means the whole "column").
After P&R, I found that my design's sub-modules do not occupy any resource (LUT nor FF) in the SLICE area which I've assigned as mentioned before.
I would like to ask do these slices are reserved for other special purpose so that the P&R tools will not use these slices or there is some fix for this problem? (I'm using ISE V10.1)