Cpu device and its using method

TL;DR: In this article, an external ROM 17 storing the program for determining the function of the device and a write program therefor is freely attachably and detachably connected to a CPU device and it can be designated by a start select switch 13 whether the CPU is to be started from an internal ROM 12 or from the external ROM 13.

Abstract: PROBLEM TO BE SOLVED: To attain cost down in the case of supply as various types of products by writing a program for determining the function of a device into an internal ROM for starting a CPU after assembly without using any externally connected ROM writer, and especially by making the program in the internal ROM different from the hardware of the same configuration concerning the CPU device in which that program is written and the internal ROM is integrated. SOLUTION: An external ROM 17 storing the program for determining the function of the device and a write program therefor is freely attachably and detachably connected to a CPU device 10 and it can be designated by a start select switch 13 whether the CPU is to be started from an internal ROM 12 or from the external ROM 13. According to this designation, a ROM control circuit 14 switches the arrangement of internal ROM 12 and external ROM 13 in the address space of a CPU 11.