A 'fatal error' in 545-speak simply means it detected something significant enough to cause the CPU to shut itself down. My experience with these was that they were hardy little beasts. 'Fatal' rarely meant irrecoverable. I think the most common source of these errors I ever encountered was electrical disturbance of some sort.
Your screen-dump shows the system memory as all zeroes. This should never be the case in normal circumstances. If the normal reset commands from software haven't recovered the situation, I'd do as Struggling_forward suggests. However I'd definitely recommend leaving the CPU with battery out and power-off for several (10-15) minutes: I seem to remember seeing examples where presumably the capacitance of the mobo and other components would sometimes mean that you couldn't be certain the RAM chips had all gone back to zeroes immediately. (It was one of these paradoxes. Whenever you wanted to clear the memory the chips would decay slowly, but if you were hoping to retain an entire programme without a battery for about 1 second, sorry that was much too long!)
Good luck
Ken