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AR# 58691

Vivado Synthesis - A CRITICAL WARNING occurs that states an existing primary or secondary unit is being overwritten [Synth 8-4527] or [Synth 8-4528]


These warnings occur when an entity or module name is given to synthesis more than once. This most often occurs when using IPs in Vivado when those IPs are different versions. Many of these IPs use the same base RTL, so if there are multiple IPs with different versions, very likely this situation will occur.

It is strongly recommended that this critical warning be fixed. 


There are two ways to fix this issue.

  • You can update all the IPs in the design to the same version. If the IPs are all from the same version, then even though the RTL is used twice, it is all the same so that the definitions will not have to be overwritten.
  • You can switch your IPs to use the OOC flow. In this flow, each IP is run on its own so RTL from one run will not affect RTL in other runs.
AR# 58691
Date Created 12/05/2013
Last Updated 12/11/2013
Status Active
Type Known Issues
  • Vivado Design Suite