max frequency with TSMC .18u std cell library

[whizkid]

Hi all,
what is the max frequency you have achieved with TSMC 18um library.
I an trying to synthesise a design at 528Mhz(1.8ns). Design Compier
results shows that the synthesis timing constraints were met. But when
I do netlist simulations I am getting 1000's of timing violations...I
checked the verilog simulaton model for the library and found that the
setup and hold checks are done in the library for 1ns ... ie for a
clock edge I need 1+1 ns for just satisying the setup hold
constraints... well my doubt is why the DC tool says the timing
constraints are met.. do you have any idea.

thanks
whizkid

 

[Kai Harrekilde-Petersen]

Hi all,
what is the max frequency you have achieved with TSMC 18um library.
I an trying to synthesise a design at 528Mhz(1.8ns). Design Compier
results shows that the synthesis timing constraints were met. But when
I do netlist simulations I am getting 1000's of timing violations...I
checked the verilog simulaton model for the library and found that the
setup and hold checks are done in the library for 1ns ... ie for a
clock edge I need 1+1 ns for just satisying the setup hold
constraints... well my doubt is why the DC tool says the timing
constraints are met.. do you have any idea.

Sounds like you haven't backannotated the netlist with SDF.


Kai

 

[Tom Verbeure]

Just an idea: could it be that you set the accuracy of the verilog
simulator to 1 ns? In this case, all timings will be rounded up to a
multiple of 1 ns...

Tom