Methods of computing with digital multistate phase change materials

A method of addition comprising the steps of:

• providing a digital multi-state 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;
• storing a first number in a first portion of said phase change material, said storing a first number including providing energy characteristic of said first number to said first portion of said phase change material,
• providing energy characteristic of a second number to said phase change material.

A method of addition comprising the steps of:

• providing a digital multistate 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;
• defining programming states for said phase change material, said programming states being selected from said plurality of states, said programming states having programming energies, said programming energies corresponding to the amount of energy required to transform said phase change material from its reset state to said programming states;
• said programming energies not exceeding said set energy of said reset state;
• assigning numerical values to said programming states;
• storing a first number in a first portion of said phase change material, said storing a first number including providing energy in an amount sufficient to transform said first portion of said phase change material to the programming state associated with the numerical value of said first number;
• providing energy characteristic of a second number to said phase change material.

A method of addition comprising the steps of:

• providing a digital multistate 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;
• partitioning at least a portion of said phase change material into memory groups, each of said memory groups corresponding to the volume of said phase change material allocated for the purpose of storing a multidigit number;
• dividing said memory groups into a plurality of registers, said registers corresponding to the portion of said memory group allocated for the purpose of storing a digit of said multidigit number, said registers having programming states, said programming states being selected from said plurality of states of said phase change material, said programming states having programming energies, said programming energies corresponding to the amounts of energy required to transform said phase change material from its reset state to said programming states;
• said programming energies not exceeding said set energy of said reset state;
• assigning numerical values to said programming states;
• associating place values with the registers of said memory groups, each of said memory groups including the same place values;
• writing a first multidigit number to a first memory group, said writing including storing the digits of said multidigit number in the registers of said first memory group according to place value, said storing including transforming said registers to the programming states associated with the numerical values of said digits;
• providing energy characteristic of a second number to said phase change material.

A method of subtraction comprising the steps of:

• providing a digital multi-state 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;
• storing a first number in a first volume of said phase change material, said storing a first number including providing energy characteristic of said first number to the reset state of said first volume of said phase change material, said energy characteristic of said first number not exceeding said set energy of said reset state;
• storing a second number in a second volume of said phase change material, said storing a second number including providing energy characteristic of said second number to the reset state of said second volume of said phase change material, said energy characteristic of said second number not exceeding said set energy of said reset state;.
• providing a first set energy to said first volume of said phase change material, said first set energy transforming said first volume of said phase change material to its set state;
• providing said first set energy to said second volume of said phase change material.

A method of multiplying a first number with a second number comprising the steps of:

• providing a digital multi-state 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;
• storing said first number in a first portion of said phase change material;
• setting a multiple register to an initial value;
• for values of the multiple register less than the sum of said initial value and said second number, performing the following steps a-b:
• a. adding said first number to the number stored in said first portion of said phase change material, said adding including providing energy characteristic of said first number to said first portion of said phase change material;
• b. incrementing said multiple register;
• reading the value stored in said first portion of said phase change material.

A method of dividing a first number by a second number comprising the steps of:

• providing a digital multi-state 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;
• storing said first number in said phase change material;
• setting a multiple register to an initial value;
• while the number stored in said phase change material is greater than or equal to said second number, iteratively performing the following steps a-b:
• a. subtracting said second number from said number stored in said phase change material, said subtracting including providing energy to transform said phase change material to a state corresponding to the difference between said stored number and said second number;
• b. incrementing said multiple register;
• reading the number stored in said phase change material;
• reading the value of said multiple register.

A method of computing the complement of a number comprising the steps of:

• providing a digital multi-state 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;
• storing a number in a first portion of said phase change material, said storing including providing energy corresponding to said number to the reset state of said phase change material;
• said corresponding energy not exceeding said set energy of said reset state;
• providing setting energy to said first portion of said phase change material, said setting energy transforming said first portion of said phase change material to its set state;
• providing said setting energy to a second portion of said phase change material.