I'm doing a Post-Route Simulation simulation in ModelSim V6.1a and having problem with physical paths delays.
The placed & routed netlist and associated SDF delay file are created with Lattice ispLever V5.1.
The problem is that propagations times from all signals are not the same on ModelSim wave window compare with the propagations times display on SDF file.
On the .SDF file and the Place & Route Trace Report .TWR file I found 2.887 ns between the output F0 of SLICE_1442 and the input D1 of SLICE_1384.
On ModelSim the same physical path had a propagation delay of 5.487 ns!!!!
The question is simple: Why a difference here?
Useless to say that the whole simulation is wrong and the only solution is to increase the clock period...
Thanks, Dan NITA
.TWR FILE RAPPORT: CTOF_DEL --- 0.310 R8C11A.D0 to R8C11A.F0 SLICE_1442 ROUTE 5 2.377 R8C11A.F0 to R3C15D.D1 instMotorsDriver_N_23 CTOOFX_DEL --- 0.510 R3C15D.D1 to R3C15D.OFX0 instMotorsDriver_sigAccumulator_20_8_0_13/SLICE_1384 ROUTE 1 0.000 R3C15D.OFX0 to R3C15C.FXB instMotorsDriver_instDriverProcessor_N_323
.SDF FILE RAPPORT: (CELL (CELLTYPE "instMotorsDriver_sigAccumulator_20_8_0_13_SLICE_1384") (INSTANCE instMotorsDriver_sigAccumulator_20_8_0_13_SLICE_1384I) (DELAY (ABSOLUTE (IOPATH D1 OFX0 (510:571:632)(510:571:632)) ........... ) ) ) (INTERCONNECT SLICE_1442I/F0 instMotorsDriver_sigAccumulator_20_8_0_13_SLICE_1384I/D1 (2377:2563:2749)-(2377:2563:2749))