Microcomputer having built-in nonvolatile memory for simultaneous use as a program area and a data area

摘要

A 1-chip microcomputer having a built-in nonvolatile memory includes at least one erasable flash memory provided in a memory space of the microcomputer, a boot ROM for storing an initial program to start up the 1-chip microcomputer and a transfer program to transfer the initial program to the flash memory, and control means for, when the flash memory stores no program, transferring the initial program to the flash memory in accordance with the transfer program and subsequently removing the boot ROM from the memory space. Consequently, even if a new program is additionally stored to the nonvolatile memory in the 1-chip microcomputer, the additional program can be carried out.