Quartus® Prime Standard Edition User Guide: Design Compilation

ID 683283
Date 10/22/2021
Document Table of Contents

2.2. Incremental Compilation Overview

Quartus® Prime incremental compilation is an optional compilation flow that enhances the default Quartus® Prime compilation. If you do not partition your design for incremental compilation, your design is compiled using the default “flat” compilation flow.

To prepare your design for incremental compilation, you first determine which logical hierarchy boundaries should be defined as separate partitions in your design, and ensure your design hierarchy and source code is set up to support this partitioning. You can then create design partition assignments in the Quartus® Prime software to specify which hierarchy blocks are compiled independently as partitions (including empty partitions for missing or incomplete logic blocks).

During compilation, Quartus® Prime Analysis & Synthesis and the Fitter create separate netlists for each partition. Netlists are internal post-synthesis and post-fit database representations of your design.

In subsequent compilations, you can select which netlist to preserve for each partition. You can either reuse the synthesis or fitting netlist, or instruct the Quartus® Prime software to resynthesize the source files. You can also use compilation results exported from another Quartus® Prime project.

When you make changes to your design, the Quartus® Prime software recompiles only the designated partitions and merges the new compilation results with existing netlists for other partitions, according to the degree of results preservation you set with the netlist for each design partition.

In some cases, Altera recommends that you create a design floorplan with placement assignments to constrain parts of the design to specific regions of the device.

You must use the partial reconfiguration (PR) feature in conjunction with incremental compilation for Stratix® V device families. Partial reconfiguration allows you to reconfigure a portion of the FPGA dynamically, while the remainder of the device continues to operate as intended.