HRR-10106: Registers With Keep Assignment

The Keep attribute on registers (in designs using Intel® Hyperflex™ architecture) always prevents Hyper-Retimer from retiming registers, limiting the achievable design performance.
Note: Use of this rule requires that the Report Source Assignments option is On in the Advanced Synthesis Settings dialog box. This option is on by default.

Recommendation

Review the use of keep attribute to determine if you can remove or change the attribute to a less restrictive pragma, such as preserve_syn_only.

Severity

Low

Stage

Analysis and Elaboration

Device Family

  • Intel® Stratix® 10
  • Intel® Agilex™
  • Intel® Cyclone® 10 GX
  • Intel® Arria® 10