Intel® Quartus® Prime Pro Edition User Guide: Design Optimization

ID 683641
Date 10/04/2021
Public

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5.5.8.4. Programmable Delays

You can use various programmable delay options to minimize the tSU and tCO times. Programmable delays are advanced options that you use only after you compile a project, check the I/O timing, and determine that the timing is unsatisfactory.

The Intel® Quartus® Prime software automatically adjusts the applicable programmable delays to help meet timing requirements. For detailed information about the effect of these options, refer to the device family handbook or data sheet.

After you have made a programmable delay assignment and compiled the design, you can view the implemented delay values for every delay chain and every I/O pin in the Delay Chain Summary section of the Compilation Report.

You can assign programmable delay options to supported nodes with the Assignment Editor. You can also view and modify the delay chain setting for the target device with the Chip Planner and Resource Property Editor. When you use the Resource Property Editor to make changes after performing a full compilation, recompiling the entire design is not necessary; you can save changes directly to the netlist. Because these changes are made directly to the netlist, the changes are not made again automatically when you recompile the design. The change management features allow you to reapply the changes on subsequent compilations.

Although the programmable delays in newer devices are user-controllable, Intel recommends their use for advanced users only. However, the Intel® Quartus® Prime software might use the programmable delays internally during the Fitter phase.

For details about the programmable delay logic options available for Intel devices, refer to the following Intel® Quartus® Prime Help topics: