NCVerilog problem with nospecify and notimingcheck options

[leeguoxian]

Dear All :

I used to think that for prelayout gate level netlist , we can use nospecify and notimingcheck option to run simulation to verify wihtout sdf annotated . But I used these two option for both ncverilog and vcs , and result turn out to be different . Ncverilog failed while vcs passed .

I am now confused that whether should I use nospecify and notimingcheck again ? Or when should I use these option .

Thanks

 

[santhosh007]

nospecify

Dear All :

I used to think that for prelayout gate level netlist , we can use nospecify and notimingcheck option to run simulation to verify wihtout sdf annotated . But I used these two option for both ncverilog and vcs , and result turn out to be different . Ncverilog failed while vcs passed .

I am now confused that whether should I use nospecify and notimingcheck again ? Or when should I use these option .

Thanks

This is classic problem of the ncverilog and vcs simualtors. by default, notiming check is enabled. incase of nospecify is depends on the library. i do have similar issues. in ncverilog try runnning without nospecify.