Isadore warns "Don't drink the SNPS/CDNS timing Kool-Aid!"

Hi John, I want to follow up with some "check to see if there is water in the pool before you dive in" warnings. There is a lot of confusion out there on:

- what are corners,

- the difference between traditional sign-off corners and global corners,

- how derates work, and

- how STA uses all of the above.

WARNING: Synopsys and Cadence are pushing new capabilities in derates and timing that are NOT compatible with existing sign-off practices -- and these derates are NOT blessed by TSMC, Samsung, nor GlobalFoundries. Before you sign up to Synopsys or Cadence derates for sign-off, it pays to learn what this all means.