Forum Discussion
Contributor22.1 PRO: (*preserve_for_debug*) signals not preserved
Hello,
Alright thanks for the feedback. I've let them know that you expect this fix to apply to all data types.
In the meantime your only workaround is to have the signal connected to an i/o port.
With that, I now transition this thread to community support. If you have a new question, feel free to open a new thread to get the support from Intel experts. Otherwise, the community users will continue to help you on this thread. Thank you.
Regards,
Nurina
P/S: If you like my comment, feel free to give Kudos. If my comment solved your problem, feel free to accept my comment as solution.
Super ContributorIf it's not going to get connected to anything, that's not what preserve for debug is for. Instead, add a virtual pin assignment to the node. Preserve for debug is to preserve internal nodes through the compilation and optimization process, maintaining their names so they can be easily added to post-fit debugging tools like Signal Tap. Virtual pins are logic stubs created to prevent I/O from getting optimized away.
ContributorThank you for the precision, I understand for a no-driver net, nevertheless for a no-fanout net, in the ug 683236:
noprune : Prevents Intel Quartus Prime from removing or optimizing a fanout free register
If it isn't the case, this is something Intel should add in Quartus, adding virtual pins must be done automatically by Quartus or the preserve_for_debug attribute is meaningless. Moving from Xilinx to Quartus, this debug workflow seems inefficient.
Regards,
