| 摘要 |
PROBLEM TO BE SOLVED: To provide a microcomputer capable of testing all addresses of a built-in ROM without changing operation modes and its testing method. SOLUTION: This microcomputer is provided with a read only memory 3 in which a program is stored, an external ROM 2 in which a test program for testing the memory 3 is stored, a central processing unit 7 reading and executing a program or the test program and an instruction outputting circuit which gives an instruction to jump to the address of the ROM 2 to the unit 7 when a ROM test signal is inputted from the outside and also when a reset signal 6 returning the unit 7 to an initial state becomes low. Since a test to the read only memory is executed when a prescribed signal is inputted from the outside to release reset in this way, it is possible to perform a test in an operation mode without having to change operation modes if the operation mode desired to be tested is preliminarily set. |
