An error condition that changes the normal flow of control in a program. An exception may be generated ("raised") by hardware or software. Hardware exceptions include reset, interrupt or a signal from a {memory management unit}. Exceptions may be generated by the {arithmetic logic unit} or {floating-point unit} for numerical errors such as divide by zero, overflow or underflow or {instruction decoding} errors such as privileged, reserved, {trap} or undefined instructions. Software exceptions are even more varied and the term could be applied to any kind of error checking which alters the normal behaviour of the program. (1994-10-31)
