Addressing peripherals in an IC

A method of addressing a peripheral in an integrated circuit comprising a processor and a set of peripherals, the method comprising:

• receiving an access address from the processor;
• transforming the access address into a transformed access address using a permanent key incorporated into the integrated circuit;
• and
• using the transformed access address to allow the processor to access a corresponding one of the peripherals, the processor only supplying the access address in order to access the peripherals.

A method of making an integrated circuit, the method comprising:

• providing a processor and a set of peripherals;
• incorporating a permanent key into the integrated circuit;
• providing a transform logic to receive at least one access address from the processor and to transform the at least one access address into at least one transformed access address using a value of the permanent key to generate a transformed access address, wherein the at least one transformed access address is generated using a transform logic comprising a plurality of logic gates;
• and
• providing a peripheral address decoder arranged to receive access addresses including the at least one transformed access address from the processor and to map a respective access address onto each of the peripherals so as to allow the processor to access a corresponding one of the peripherals, the processor only supplying the access address in order to access the peripherals.

A method of supplying integrated circuits to first and second users, each integrated circuit comprising a processor, a set of peripherals, and an address map for mapping a respective access address onto each of the peripherals stored as a permanent key within at least one of the integrated circuits;

• the method comprising:
• supplying a first integrated circuit having a first address map to the first user, and supplying a second integrated circuit having a second address map to a second user,
• wherein the first and second integrated circuits are functionally identical except in that the first address map is different from the second address map, the first and second access address map are used to provide access to the first and second integrated circuit using at least one transformed access address generated using a transform logic comprising a plurality of logic gates;
• and
• wherein a processor of the first or second integrated circuits can access the peripherals of the first or second integrated circuits by only supplying the access addresses specified by the respective first or second address map.