Honored Contributor
Honored ContributorI think you're seeking alt_log_printf()
https://www.altera.com/content/dam/altera-www/global/en_us/pdfs/literature/hb/nios2/edh_ed51003.pdf When things go off the deep end, the best tool unique to this environment that I have found is the SignalTap NIOS plugin, which doesn't get mentioned very frequently: https://www.altera.com/content/dam/altera-www/global/en_us/pdfs/literature/an/an446.pdf And along the similar lines as writing to your LED's, you can also do things like have an assortment of PIO instances that you don't tie to anything except SignalTap or a Sources/Probes instance. For example, one PIO for "module" and one PIO for "line number" and riddle your code with TRACE() macros that write to those PIO's; hookup SignalTap and watch the writes to those PIO leading up to your crash. As far as why you are unable to break into your program, I've experienced the same but I don't think it is necessarily a load/store being stuck. Anyway - lots of things you can try, without feeling dependent on unbuffered UART's and LED's.
