Hi when I do back annotate of the sdf file with my design( syn netlist), they show some warnings in the log file. ncelab: *W,SDFNEP: Failed Attempt to annotate to non-existent path (IOPATH A Y) of instance leon_n_tb.leon.U68 of module BUFX1 <./leon.sdf, line 142574>. this is my sdf file (CELL (CELLTYPE "BUFX1") (INSTANCE U68) (DELAY (ABSOLUTE (IOPATH A Y (0.169:0.169:0.169) (0.181:0.182:0.182)) ) ) please tell me your solving way ,thank you best regards