is there any debug monitor available that can dump before the controller freezes?
Even if there was, how would it know that the program was going to freeze sometime (a few microsecs) in the future?
Put some Serial.print() statements in your code and the last one printed will give you an idea of where the program had got to before the freeze.
Things that cause programs to freeze after some time are the use of the String (capital S) class and writing beyond the bounds of an array.
If you want more help then post your program.