Two primary checks are setup and hold checks. Once a clock is defined at clock pin of a flip-flop (FF), setup and hold checks are automatically inferred for the FF. Timing checks are generally performed at multiple conditions including worst-case slow condition and best-case fast condition. Typically, worst-case slow condition is critical for setup check… read more »
What’s STA environment? Specifying Clocks. Clock uncertainty and Clock latency Generated clocks Input paths constraint Output paths constraint Timing path groups External attributes modeling Check design rules Refine timing analysis Point-to-point specification Set up environment for static timing analysis. Specification of correct constraints is important in analyzing STA results. Design environment should be specified accurately… read more »
For chip tapeout, physical design must clean timing/skew/transition violations based on OCV (on chip variation) derating in signoff STA environment. http://www.techdesignforums.com/practice/guides/on-chip-variation-ocv/ For example, when check setup violation, launch path is late, clock cell delay times 1.039, data cell delay times 1.077, capture path is early, clock cell delay times 0.961, clock net delay times 0.915…. read more »