Intel® Quartus® Prime Standard Edition User Guide: Design Compilation

ID 683283
Date 9/24/2018
Document Table of Contents

1.5.2. Design Partition Assignments Compared to Physical Placement Assignments

Design partitions for incremental compilation are logical partitions, which is different from physical placement assignments in the device floorplan. A logical design partition does not refer to a physical area of the device and does not directly control the placement of instances. A logical design partition sets up a virtual boundary between design hierarchies so that each is compiled separately, preventing logical optimizations from occurring between them. When the software compiles the design source code, the logic in each partition can be placed anywhere in the device unless you make additional placement assignments.

If you preserve the compilation results using a Post‑Fit netlist, it is not necessary for you to back‑annotate or make any location assignments for specific logic nodes. You should not use the incremental compilation and logic placement back‑annotation features in the same Intel® Quartus® Prime project. The incremental compilation feature does not use placement “assignments” to preserve placement results; it simply reuses the netlist database that includes the placement information.

You can assign design partitions to physical regions in the device floorplan using LogicLock region assignments. In the Intel® Quartus® Prime software, LogicLock regions are used to constrain blocks of a design to a particular region of the device. Altera recommends using LogicLock regions for timing-critical design blocks that will change in subsequent compilations, or to improve the quality of results and avoid placement conflicts in some cases.