Report Recovery Summary Command
Generates the Summary (Recovery) report detailing the results of setup checks for paths that contain an asynchronous clear, preset, or load signal. This report can alert you to a condition in which an active clock edge occurs too soon after the asynchronous input becomes inactive, thus rendering the data unknown. A positive slack value indicates the margin by which a timing requirement was achieved. A negative slack value indicates the margin by which the requirement was not achieved.
The report also displays the target Definition TNS (Total Negative Slack), which is the sum of all slacks less than zero for either destination registers or ports in the clock domain (endpoint TNS). You can use TNS as an additional metric to troubleshoot a design that fails to meet timing constraints.