When implementing a design with a number of MARK_DEBUG RTL attributes, opt_design fails with the following error:
How can this be avoided?
The error is due to a MARK_DEBUG net having no driver.
During opt_design, the ILA logic is added and the net connecting to the D pin of the SRL is removed because it is not being driven.
Following the SRL D pin is not possible after the error as the net has been removed. Also, the post-synthesis view will show the ILA as a black box.
One way to avoid this error is to ensure that all MARK_DEBUG nets have drivers.
For designs with a large number of MARK_DEBUG nets, the ROUTE_STATUS property of nets can be used to find the nets with no loads.
While these MARK_DEBUG nets have no loads, their loads will also be removed after opt_design.
After the error, use the following command:
Then the RTL can be adjusted to make sure that the specific net is driven.