STA problem need help!

[dolby.yang]

in sta ,to do setup and hold check, we need to select wire load mode, but there usualy have worst wire load mode and best wire load mode.how to select this two mode to do setup and hold check?

thanks!

 

[eeeraghu]

probably worst wire load model

 

[dolby.yang]

thank you !
select worst wire load mode to check setup or hold or both?

 

[bendrift]

this wire load model will be selected according design's area if u did not define explicitly.

 

[silencer3]

u must use best operating conditions for hold checks and worst operating conditions for setup check. wireload selection is same for both setup and hold check. it is the libraries and operating conditions which decides whether u r selecting worst or best conditions.

 

[papertiger]

sta requires real backend data ,not wireload model.
wireload model is only for synthesis

 

[sandysuhy]

Hi

In STA we go for best case analysis for Hold check and
worst case analysis for setup check.

 

[dolby.yang]

Hi

In STA we go for best case analysis for Hold check and
worst case analysis for setup check.

thank you,i want to know the reason ,can u explain it for me?

 

[hyena_dale]

setup time = clock cycle - max data delay
hold time = max clock delay(skew) - min data delay

With worst case condition, setup time can get most critical value,
With best case condition, hold time can get most critical value in mostly environment.

 

[dolby.yang]

setup time = clock cycle - max data delay
hold time = max clock delay(skew) - min data delay

With worst case condition, setup time can get most critical value,
With best case condition, hold time can get most critical value in mostly environment.

thank you! you are right.

 

[spauls]

try OCV (On Chip Variation) mode also

 

[lailiya]

hi dolby,
In fact, wire load mode is based on statistic, so it has low accuracy for timing analysis excecially for hold check. So i think it is better to do hold check with RC information instead of WLM

 

[pamulurureddy]

n STA we go for best case analysis for Hold check and
worst case analysis for setup check.