How do you get PrimeTime to report a hold check instead of a setup check with report_timing?

Short Answer

By default report_timing (PT) reports the setup (max delay) check for the worst path, so a designer chasing a hold problem can stare at the wrong check without realizing it. Adding -delay_type min (PT) tells the command to report the minimum-delay, hold-side check instead, which uses a different required time and often a different worst path entirely.

Technical Explanation

• Setup checks ask whether data arrives before the next clock edge; hold checks ask whether data stays stable long enough after the current edge, so they use opposite delay assumptions.
• report_timing (PT) defaults to -delay_type max, which reports the setup check using worst-case, slowest delays.
• report_timing -delay_type min (PT) switches to the hold check, which actually means using the fastest, best-case delays, since a hold violation is caused by data arriving too soon.
• Because the fastest and slowest paths through a design are often physically different, the worst hold-check path is frequently not the same instance pair as the worst setup-check path.
• Combining -delay_type min with -nworst N (PT) shows the N worst hold checks in one pass, the same way -nworst works for setup.
• A design can show a perfectly clean setup report and still carry hold violations, so both delay types need to be checked, not just the default one.

Follow-up Question & Model Response

Why does a hold fix, adding delay, never trade off against the clock period the way a setup fix does?

Candidate Model Response: A setup check compares data path delay against the clock period, so slowing the clock gives every setup check more room to pass. A hold check compares data path delay against clock skew and uncertainty at a single edge, with no period term in the inequality at all, so changing the clock frequency does nothing for a hold violation. This is why hold fixes always add real delay into the data path, a buffer, a longer wire, a slower cell, rather than relaxing the constraint. It also means hold violations must be fixed before tapeout, since no clock speed a customer could apply would make them pass.