Quartus® Prime Standard Edition User Guide: Design Compilation

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

2.5.2.7. Connect I/O Pin Directly to I/O Register for Packing Across Partition Boundaries

The Quartus® Prime software allows cross-partition register packing of I/O registers in certain cases where your input and output pins are defined in the top-level hierarchy (and the top-level partition), but the corresponding I/O registers are defined in other partitions.

Input pin cross-partition register packing requires the following specific circumstances:

  • The input pin feeds exactly one register.
  • The path between the input pin and register includes only input ports of partitions that have one fan-out each.

Output pin cross-partition register packing requires the following specific circumstances:

  • The register feeds exactly one output pin.
  • The output pin is fed by only one signal.
  • The path between the register and output pin includes only output ports of partitions that have one fan-out each.

The following examples of I/O register packing illustrate this point using Block Design File (.bdf) schematics to describe the design logic.