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

ID 683230
Date 11/12/2018
Document Table of Contents Empty Logic Lock Regions

Intel® Quartus® Prime allows you to have Logic Lock regions with no members. Empty regions are a tool to manage space in the FPGA for future logic. This technique only works when you set the regions to Reserved

Some reasons to use empty Logic Lock regions are:

  • Preliminary floorplanning.
  • Complex incremental builds.
  • Team based design and interconnect logic.
  • Confining logic placements.

Since Logic Lock regions do not reserve any routing resources, the Fitter may use the area for routing purposes.

Use the Core Only attribute for empty Logic Lock regions. When you include periphery resources in empty regions, you restrict the periphery component placement, which can result in a no fit design. After you name the empty region, you can perform the same manipulations as with any populated Logic Lock Region.

Figure 47. Logic Placed Outside of an Empty region

The figure shows an empty Logic Lock region and the logic around it. However, some IOs, HSSIO, and PLLs are in the empty region. This placement happens because the output port connects to the IO, and the IO is always part of the root_partition (top-level partition).