SLR Utilization Considerations - SLR Utilization Considerations - 2026.1 English - UG1387

The Vivado implementation tools use a special algorithm to partition logic into multiple SLRs. For challenging designs, you can improve timing closure for designs that target SSI technology devices using the following guidelines.

To improve timing closure and compile times, use Pblocks to assign logic to each SLR. Validate that individual SLRs do not have excessive utilization across all fabric resource types. For example, if a design uses 70% of block RAM utilization, it can cause timing closure issues. When block RAM resources are not balanced across SLRs, one SLR uses more than 85% of the block RAM.