Patent ID: 7440990

Claim:
A method of modular arithmetic comprising the steps of: providing an input number; providing the modulus of a modular arithmetic system; providing a volume of phase change material, said phase change material having a plurality of states, said states including: a reset state, a set state obtainable from said reset state by applying energy in an amount corresponding to the set energy of said reset state, said set state having lower resistance than said reset state, and one or more intermediate states having substantially the same resistance as said reset state, said one or more intermediate states being obtainable from said reset state by applying energy in an amount less than said set energy of said reset state; programming said phase change material according to said modulus, said programming including defining programming states, said programming states being selected from said plurality of states of said phase change material, said programming states including said reset state and said set state, the number of said programming states being one more than said modulus; and applying one or more energy pulses to said phase change material, each of said energy pulses transforming said phase change material from one of said programming states to another of said programming states, the number of said applied energy pulses equaling said input number.