Common Design Errors - 2023.1 English

Vivado Design Suite User Guide: Implementation (UG904)

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2023.1 English

One common error that can cause logic optimization to fail is using undriven LUT inputs, where the input is used by the LUT logic equation. This results in an error such as:

ERROR: [Opt 31-67] Problem: A LUT6 cell in the design is missing a connection on input pin I0, which is used by the LUT equation.

This error often occurs when the connection was omitted while assembling logic from multiple sources. Logic optimization identifies both the cell name and the pin, so that it can be traced back to its source definition.