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AR# 63785

2014.4 Vivado - ERROR: [Constraints 18-1078] Instance *_OBUF_inst does not exist.

Description

When opening an implemented design or checkpoints from opt_design, place_design and route_design, I see the following error:
 
Reading placer database...
ERROR: [Constraints 18-1078] Instance abc_OBUF_inst does not exist.
ERROR: [Constraints 18-1078] Instance abc_OBUF_inst does not exist.
ERROR: [Constraints 18-1078] Instance abc_OBUF_inst does not exist.
ERROR: [Constraints 18-1078] Net abc does not exist.

How do I correct these errors?

Solution

This issue has been seen in a design that has following features:


  1. It has one DCP submodule that has been synthesized by Vivado Synthesis with the option "-mode out_of_context".
    This submodule has an inout port defined, but not used.
  2. The top level of the design instantiates the submodule and connects the submodule's inout ports with its inout ports.
    However, the inout ports in the top module are not used either.
  3. The inout ports in the top module are LOC'd to package pins in constraints.

To work around this issue, delete the unused inout ports in the design or remove the package pin location constraints for unused inout ports.

This issue has been resolved in Vivado 2015.1.

AR# 63785
Date Created 03/03/2015
Last Updated 08/06/2015
Status Active
Type General Article
Tools
  • Vivado Design Suite - 2014.4