Intel® Quartus® Prime Pro Edition User Guide: Timing Analyzer

ID 683243
Date 10/04/2021
Public

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1.1.4. Recovery and Removal Analysis

Recovery time is the minimum length of time for the deassertion of an asynchronous control signal relative to the next clock edge.

For example, signals such as clear and preset must be stable before the next active clock edge. The recovery slack calculation is similar to the clock setup slack calculation, but the calculation applies to asynchronous control signals.

Figure 15. Recovery Slack Calculation if the Asynchronous Control Signal is Registered
Figure 16. Recovery Slack Calculation if the Asynchronous Control Signal is not Registered
Note: If the asynchronous reset signal is from a device I/O port, you must create an input delay constraint for the asynchronous reset port for the Timing Analyzer to perform recovery analysis on the path.

Removal time is the minimum length of time the deassertion of an asynchronous control signal must be stable after the active clock edge. The Timing Analyzer removal slack calculation is similar to the clock hold slack calculation, but the calculation applies to asynchronous control signals.

Figure 17. Removal Slack Calculation if the Asynchronous Control Signal is Registered

Figure 18. Removal Slack Calculation if the Asynchronous Control Signal is not Registered

If the asynchronous reset signal is from a device pin, you must create an input delay constraint to the asynchronous reset pin for the Timing Analyzer to perform removal analysis on the path.