Intel® Quartus® Prime Standard Edition User Guide: Timing Analyzer
ID
683068
Date
2/21/2024
Public
2.3.1. Recommended Initial SDC Constraints
2.3.2. SDC File Precedence
2.3.3. Iterative Constraint Modification
2.3.4. Creating Clocks and Clock Constraints
2.3.5. Creating I/O Constraints
2.3.6. Creating Delay and Skew Constraints
2.3.7. Creating Timing Exceptions
2.3.8. Example Circuit and SDC File
2.3.7.5.1. Default Multicycle Analysis
2.3.7.5.2. End Multicycle Setup = 2 and End Multicycle Hold = 0
2.3.7.5.3. End Multicycle Setup = 2 and End Multicycle Hold = 1
2.3.7.5.4. Same Frequency Clocks with Destination Clock Offset
2.3.7.5.5. Destination Clock Frequency is a Multiple of the Source Clock Frequency
2.3.7.5.6. Destination Clock Frequency is a Multiple of the Source Clock Frequency with an Offset
2.3.7.5.7. Source Clock Frequency is a Multiple of the Destination Clock Frequency
2.3.7.5.8. Source Clock Frequency is a Multiple of the Destination Clock Frequency with an Offset
1.1.5.2. Multicycle Clock Setup
The setup relationship is defined as the number of clock periods between the latch edge and the launch edge. By default, the Timing Analyzer performs a single-cycle path analysis, which results in the setup relationship being equal to one clock period (latch edge – launch edge). Applying a multicycle setup assignment, adjusts the setup relationship by the multicycle setup value. The adjustment value may be negative.
An end multicycle setup assignment modifies the latch edge of the destination clock by moving the latch edge the specified number of clock periods to the right of the determined default latch edge. The following figure shows various values of the end multicycle setup (EMS) assignment and the resulting latch edge.
Figure 27. End Multicycle Setup Values
A start multicycle setup assignment modifies the launch edge of the source clock by moving the launch edge the specified number of clock periods to the left of the determined default launch edge. A start multicycle setup (SMS) assignment with various values can result in a specific launch edge.
Figure 28. Start Multicycle Setup Values
The setup relationship reported by the Timing Analyzer for the negative setup relationship.
Figure 29. Start Multicycle Setup Values Reported by the Timing Analyzer