Microcomputer with programmable ROM

摘要

In a microcomputer with a programmable ROM, there is provided an external pin at which a mode select signal is entered so as to select one of three modes, including a MCU mode in which an application system is controlled by an application program which has been stored in the programmable ROM, a PROM mode in which the application program is written into the programmable ROM, and an inline mode in which predetermined data is written to a part of the programmable ROM with the microcomputer mounted on a user system.