| 摘要 |
<p>PURPOSE:To effectively utilize the merits of both a mask ROM and a programmable ROM without increasing a chip area or a manufacture cost by incorporating a ROM composed of the two kinds of the ROMs such as the mask ROM and programmable ROM. CONSTITUTION:A CPU 7, peripheral equipment 8, ROMs 12 and 13 and ROM 10, etc., are provided to be respectively connected to an internal bus 11, which is connected through an I/O 9 to an external part, and the two kinds of the ROMs such as the ROM 12 manufactured as the mask ROM and the ROM 13 manufactured as the programmable ROM are provided. Accordingly, a program, to which debugging is already finished, is built in the ROM 12 and it is enough for the parameter part on the program for each destination to be programmed to the ROM 13, which is the programmable ROM, before loading. Thus, the feature of the mask ROM that a circuit area is small and it is suitable for mass production, and the feature of the programmable ROM that the desired program can be successively written can be effectivel utilized.</p> |
