TMC-20550: Automatically Selected Duplication Candidate Rejected for Placement Constraint

Description

Registers that have a tight placement constraint (such as, Logic Lock, clock region, or location assignments) cannot be duplicated via automatic detection. This condition can prevent the Compiler from properly localizing connections between the fan-outs of these registers.

Recommendation

Relax the constraint to encompass the register's fan-outs, or duplicate registers by applying the DUPLICATE_REGISTER or DUPLICATE_HIERARCHY_DEPTH assignments, or edit the RTL to create duplicate copies. If you edit the RTL, apply the preserve_syn_only attribute to the duplicate registers, and assign the duplicates to individual instances in the fan-out hierarchy.

Severity

Low

Tags

Tag Description
register-duplication Design rule checks related to duplication of registers in the design, either manually or automatically.
place Design rule checks which pertain to the Compiler's Place stage.

Device Family

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