Quartus® Prime Standard Edition User Guide: Design Compilation

ID 683283
Date 10/22/2021
Document Table of Contents Using Assignments to Limit the Number of RAM and DSP Blocks

For DSP and RAM block balancing, you can use assignments to limit the maximum number of blocks that the balancer allows. You can set these assignments globally or on individual partitions. For DSP block balancing, the Maximum DSP Block Usage logic option allows you to specify the maximum number of DSP blocks that the DSP block balancer assumes are available for the current partition. For RAM blocks, the floorplan-aware logic option allows you to specify maximum resources for different RAM types, such as Maximum Number of M4K/M9K/M20K/M10K Memory Blocks, Maximum Number of M512 Memory Blocks, Maximum Number of M-RAM/M144K Memory Blocks, or Maximum Number of LABs.

The partition-specific assignment overrides the global assignment, if any. However, each partition that does not have a partition-specific assignment uses the value set by the global assignment, or the value derived from the device size if no global assignment exists. This action can also lead to over allocation. Therefore, Altera recommends that you always set the assignment on each partition individually.

To select the Maximum Number <block type> Memory Blocks option or the Maximum DSP Block Usage option globally, click Assignments > Settings > Compiler Settings > Advanced Settings (Synthesis). You can use the Assignment Editor to set this assignment on a partition by selecting the assignment, and setting it on the root entity of a partition. You can set any positive integer as the value of this assignment. If you set this assignment on a name other than a partition root, Analysis & Synthesis gives an error.