Keyword: bit slices, Virtex 5, SYR, utilization
The synthesis report for Virtex-5 mentions "Bit Slices" in the Device Utilization Summary. What is a bit slice?
A "Bit Slice" is the same as a "LUT-Flop pair" or "LUT-FF pair."
The MAP report refers to "LUT-Flop" pairs rather than "bit slices." See (Xilinx Answer 23515) for more information on Virtex-5 Slice Logic Utilization.