A method is provided for injecting faults into an operational system
containing software and hardware components to be tested. A fault
injection routine is stored in a memory location of the system. An
interrupt service routine, preferably operational during normal operation
of the system is provided with a pointer to the fault injection routine.
A fault injection routine is executed from within the interrupt service
routine. In one embodiment, the interrupt service routine provides a
clock or timing function. In another embodiment, a number of fault
injection subroutines are accessible by the fault injection routine. A
value is passed to the fault injection routine indicating the particular
fault injection subroutine to be employed.