RETIMING_FORWARD - 2025.2 English - UG901

The RETIMING_FORWARD attribute instructs the tool to move a register forward through logic closer to the driven sequential elements. This attribute is not timing-driven and works regardless of whether the retiming global setting is active or if there are even timing constraints. If the global retiming setting is active, first the RETIMING_FORWARD step executes, and then global retiming enhances that register to move further back the chain. However, it does not interfere with the attribute and moves the register back to the original location.

The RETIMING_FORWARD attribute takes an integer as a value. This value describes how much logic the register can cross. Larger values allow the register to cross more logic. 0 turns the attribute off.