We have use the MB90F598G for many years, but have recently begun seeing some strange behavior.
They will always start up correctly on a power-on reset, however either a RST + HST or software reset does not. In this case, they will either not start at all, or hang for a long time (30-100s) before starting up. And it is not consistent, they might do proper resets many times in a row, and then begin to fail and only fail.
We have checked VCC, that RST + HST is released properly. Any suggestions as to what is going on, other than a faulty MCU?
What we also cannot really figure out, is the difference between power-on and RST. In both cases RST + HST is held, and when released power-on will boot, and the other wont.
