CLOCK GLITCH MITIGATION APPARATUS AND METHOD

An apparatus and method to protect unauthorized change to a reference clock for a processor. The apparatus comprises: a first oscillator to generate a first clock; a second oscillator to generate a second clock; a third oscillator to generate a third clock; a first counter to count frequency of the first clock with respect to a fourth clock; a second counter to count frequency of the second clock with respect to the fourth clock; a third counter to count frequency of the third clock with respect to the fourth clock; and a circuitry to compare frequencies of the first, second, and third clocks with one another. The oscillators can be embedded in an interposer or package. These oscillators include one or more of: LC oscillator, micro electro-mechanical system (MEMs) based resonator, or ring oscillator.