Intel® Hyperflex™ Architecture High-Performance Design Handbook

ID 683353
Date 10/04/2021

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Document Table of Contents Optimize Multicycle Paths

The Compiler does not retime registers that are the endpoints of an .sdc timing constraint, including multicycle or false path timing constraints. Therefore, assign any timing constraints or exceptions as specifically as possible to avoid retiming restrictions.

Using actual register stages, rather than a multicycle constraint, allows the Compiler the most flexibility to improve performance. For example, rather than specifying a multicycle exception of 3 for combinational logic, remove the multicycle exception and insert two extra register stages before or after the combinational logic. This change allows the Compiler to balance the extra register stages optimally through the logic.