Recovery and removal checks
Beginner
Timing rules for when the chip’s reset button is let go, so memory cells start up cleanly.
Novice
Timing checks on the moment a reset signal is released. A reset forces flip-flops to a known value; releasing it too close to a clock tick can leave a flip-flop undecided. Recovery checks the release happens early enough before the tick, removal that it happens late enough after it.
Expert
The setup-like (recovery) and hold-like (removal) checks on the release edge of an asynchronous set or reset pin, relative to the clock. A violation can leave the flop metastable as it leaves reset. Reset nets fan out like clocks, so reset synchronizers make release synchronous to each clock domain, and STA checks every asynchronous pin in every scenario.
Explained in Signoff (Design Flow).