A test stimulus generator generates error irritations, or error sequences, within a processor system. The test stimulus generator includes an initialization register, a pseudorandom number generator (PRNG), a clock subsystem, and an output register. The PRNG calculates an output value from an initialization value stored in the initialization register. The PRNG output value represents a unique error irritation and identifies one or more components within the processor system to handle the error irritation. The clock subsystem generates either a continuous or pulsed clock signal that transfers the initialization value into the PRNG. The output register stores the PRNG output value and transmits the corresponding error irritation to the processor components identified to handle the error irritation. The test stimulus generator generates error irritations in a predetermined or random order based on the initialization value. A corresponding method and computer program product are also disclosed.