It is possible to replace debug nets connected to an ILA core in a placed and routed design checkpoint. You can do this by using the Engineering Change Order (ECO) flow. This is an advanced design flow used for designs that are nearing completion, where you need to swap nets connected to an ILA probe port. This method serves two purposes:
- It saves you time. This feature lets you swap existing debug nets that are being probed for different nets.
It is minimally invasive. After replacing probed nets, it
is necessary to route those nets to the inputs of the debug core. The rest of the
design remains intact, thereby not only preserving previous implementation results,
but also reducing the possibility that a re-implementation will hide the bug you are
trying to find.Important: This flow is only applicable to designs where ILA cores have already been instantiated or inserted.
The following figure shows the process of replacing debug nets using the ECO design flow.
Figure 1. Debug ECO Design Flow