ID 683068
Date 9/24/2018
Public

## 2.2.5.3. Fmax Summary Report

The Fmax Summary Report panel lists the maximum frequency of each clock in your design.
Figure 38. Fmax Summary Report

In some cases the Fmax Summary may indicate a "Limit due to hold check." Typically, hold checks do not limit the maximum frequency (fMAX) because these checks are for same-edge relationships, and therefore independent of clock frequency. For example, when launch equals zero and latch equals zero.

However, if you have an inverted clock transfer, or a multicycle transfer (such as setup=2, hold=0), then the hold relationship is no longer a same-edge transfer and changes as the clock frequency changes.

The value in the Restricted Fmax column incorporates limits due to hold time checks, as well as minimum period and pulse width checks. If hold checks limit the fMAX more than setup checks, that is indicated in the Note column as "Limit due to hold check."