I met problem while doing place for Spartan-3 in ISE 7.1 .They said. Number of BUFGMUXs 2 out of 8 25% Number of External IOBs 31 out of 221 14% Number of LOCed IOBs 0 out of 31 0%
Number of Slices 9643 out of 13312 72% Number of SLICEMs 52 out of 6656 1% WARNING:Place:119 - Unable to find location. SLICEL component ins_rsa_core_combine/U_reg not placed. ...... ...... ..... 0,256 ins_rsa_core_combine/U_reg ERROR:Place:120 - There were not enough sites to place all selected components
I used large width register and adder in this design, the reg will map into FF with the SLICES? And I can see SLICEM only used 52. If the silces is not enough, why the tools did not use SLICEM?