positive and negative slack
hey,
"negative slack means .....is it -ve slack means -ve setup or -ve hold ? "
negative slack cn occur both for setup and hold !
When u perform setup analysis, if your arrival time ( Tcq + Tcombi) is greater than required time ( Clock Period- Tsu), then u get a "-ve slack" for setup !
similarly if u r doin a hold analysis, u wil get a "-ve slack", if ur arrival time(Tcq + Tcombi) is lesser than the required time ( Th of the flip flop)
clear ?
phutanesv has explained it verr clealy in both of his replies.