Post-Route Simulation does not give output for the first clo

D

Drew

Guest
Hi,

I designed a 3 stage pipelined floating point adder/subtractor (IEEE
754 floating point arithmetic).

I am using Xilinx ISE 9.1a environment to code and Modelsim to
simulate.

I am getting correct outputs for all the clock cycles in behavioral
simulation. However, in Post-Route simulation, I am not getting
output for the first data pair given for the arithmetic. In the next
clock cycles, output is coming correctly. When I increased the period
to 200 ns, output is coming correctly in the first clock cycle also.
But, I did not understand why it is giving correct output when the
period is increased to 200 ns from 80 ns.

In the detailed Design summary produced after the Post-Route
simulation, I saw that the minimum time period is 24 ns. But, I am
getting output for the first clock cycle only when the period is
increased to 200 ns. Please throw some light about what is happening.

Thanks and Regards,
Vamsi.
 

Welcome to EDABoard.com

Sponsor

Back
Top