0:00 / 0:35
DFT / Test
Source: PrimeTime User Guide Version T-2022.03
Okay, let's take this gently. Under best-case conditions, gates switch fastest, so the real risk flips to hold violations rather than setup. That is the key finding here: fast silicon shrinks delays, threatening data stability at the capture flop. See this bit? The clock reaches DL2 through a longer max_path while launching from DL1 on a shorter min_path. That skew, plus quick combinational logic, means new data can race in before the old value is safely latched. Oh, that is clean once it clicks. We check hold at BEST precisely because speed hurts us here. Does that land?
Okay, let's take this gently. This board maps a single timing path under worst-case conditions, which is exactly where setup margins get tightest. See how the clock splits at CLK? One branch takes the slowest route to DL1's ck, while the other races to DL2. That skew matters. Hmm, look here. The data arc leaving DL1 crosses the combinational logic as a max_path@WORST, landing right at DL2's d pin just before setup@WORST closes the window. Meanwhile, min_path@WORST governs the capture clock edge. Does that click? We deliberately pair the longest data delay with the shortest clock delay to stress the constraint. Oh, that's clean. It guarantees our design survives the harshest silicon corner.
Okay, let's take this gently—first, we have the best-case timing analysis. In this scenario, we are looking at the minimum path delays, which is denoted by min_path@BEST. This helps us understand the fastest possible performance of our design. Now, see this bit? We contrast it with the worst-case timing analysis. Here, we focus on the maximum path delays, represented by max_path@WORST. This gives us a clear picture of the slowest possible performance, ensuring we account for all potential issues. Let's walk through it. To switch from best-case to worst-case, you need to use specific commands. For the worst-case, you set the operating conditions with 'set_operating_conditions WORST' and then report the timing with 'report_timing -delay_type max'. Does that click? These commands help you transition between the two scenarios, allowing you to thoroughly analyze your design under different conditions. It’s important to run both analyses to ensure your design is robust and reliable. One step at a time. By understanding these steps, you can better manage the timing paths in your design, ensuring it performs well under all conditions. Let’s make sure we get this right before moving on.