Modelsim Simulation

Apr 27, 2006 1 Replies

I have a mismatch in Modelsim behavioral simulations using 1) VHDL testbench in ISE and 2) manual entry of stimuli.



While the vector inputs are same in time and values in both cases, the output, however, is different. The manual simulation seems working as designed but the testbench based simulation has a delayed output and the current state of FSM is stuck to certain state.



This is the first time I have encountered this problem, otherwise I have been consistently getting same results whether I manually simulate the design or use a testbench. I am quite clueless here. I don't know whether the problem is attributed to the Modelsim or the design itself since Modelsim gives two different results on same source file, the mode of simulation is different though.



Regards,



YZ



hey Yaseen; i dont think so. modelsim and ur testbench should produce same results. modelsim is basically the simulation tool. check at the clock, input values, control signals and since you have to force values in modelsim, check out if u doing it correctly. the timing is the same.

Cheers Abbs

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