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
2.3.5.2. Output Constraints (set_output_delay)
Output constraints specify all external delays from the device for all output ports in your design.
set_output_delay -clock { clock } -clock_fall -rise -max 2 foo
Use the Set Output Delay (set_output_delay) constraint to specify external output delay requirements. Specify the Clock name (-clock) to reference the virtual or actual clock. When specifying a clock, the clock defines the latching clock for the output port. The Timing Analyzer automatically determines the launching clock inside the device that launches the output data, because all clocks in the device are defined. The following figure is an example of an output delay referencing a virtual clock.
Figure 55. Output Delay Diagram
Figure 56. Output Delay Calculation