Intel® Quartus® Prime Software
Intel® Quartus® Prime Design Software, Design Entry, Synthesis, Simulation, Verification, Timing Analysis, System Design (Platform Designer, formerly Qsys)

Simulation delay problem

Altera_Forum
Honored Contributor II
1,575 Views

heey all, 

i've done writing a vhdl code on Quartus || but i faced this problem  

when i simulate in functional simulation mode, the circuit is doing well and the output comes as it's expected!  

but when simulating the whole code on Timing mode, the circuit seems not to function correctly and the output is wrong for the same input of the above iteration!  

if the problem is due to delay, please tell me how can i solve it  

and will i face problems when downloading the code on FPGA ? 

... 

Thanks in advance!
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Altera_Forum
Honored Contributor II
536 Views

First, you need to correctly set timing contraints for your design. 

 

http://alterawiki.com/wiki/timequest_user_guide
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Altera_Forum
Honored Contributor II
536 Views

Hi,  

Maybe a newbie mistake :  

Are you using "mysignal <= other signal after 20 ns;" ? 

Keep in mind that "after" is not synthetizable.
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