Method and apparatus for emulating rewritable memory with non-rewritable memory in an MCU

An integrated circuit having an embedded multiple time programmable memory, comprising:

• a program address space of a defined size;
• a multiple time programmable (MTP) non-volatile memory block for storing program instructions for use during an operational mode of the integrated circuit, said MTP memory block operating within an MTP address space, said MTP memory including:
• a plurality of MTP blocks of non-volatile memory, each of which can be written to once and read from many times and each having a size that is equal to or less than said program address space, and
• a reserve storage location for storing a status word defining the one of said plurality of MTP blocks that can be addressed from within said program address space, said status word operable to be changed in response to external signals when another of said plurality of MTP blocks is to be selected, such that once another of said plurality of MTP blocks is selected, said status word cannot indicate as addressable within said program address space a prior one of said plurality of MTP blocks that was defined by said status word as being previously addressable within said program address space;
• and
• an access device for enabling a program memory address within the program memory address space to address a corresponding addressable location within the one of said plurality of MTP blocks indicated by said status word as being addressable within said program address space.

A method for storing program instructions in an integrated circuit, comprising the steps of:

• defining a program address space of a defined size;
• providing an embedded multiple time programmable (MTP) non-volatile memory block in the integrated circuit for storing program instructions for use during an operational mode of the integrated circuit, and the MTP memory block operating within an MTP address space;
• parsing the MTP memory into a plurality of MTP blocks of non-volatile memory, each of which can be written to once and read from many times and each having a size that is equal to or less than the program address space;
• defining a reserve storage location within the MTP memory and storing therein a status word defining the one of said plurality of MTP blocks that can be addressed from within said program address space, the status word operable to be changed in response to external signals when another of the plurality of MTP blocks is to be selected, such that once another of the plurality of MTP blocks is selected, the status word cannot indicate as addressable within the program address space a prior one of the plurality of MTP blocks that was defined by said status word as being previously addressable within said program address space;
• and
• enabling a program memory address within the program memory address space to address a corresponding addressable location within the one of the plurality of MTP blocks indicated by the status word as being addressable within the program address space.