| 摘要 |
<p>PURPOSE:To perform an internal test and to freely change the content of the test without using an external signal, by switching a ROM area to a test area and a program area with an external pin. CONSTITUTION:Whether access is performed to a program ROM 3 area or to a test ROM 4 area is controlled by a test dedicated pin 2. For example, when the test dedicated pin is pulled down, the test ROM 4 area is accessed, and when a test mode is set, the test ROM 4 area is accessed with a microprocessor in a microcomputer by activating a reset pin 7 afterwards, and a self-checking test evaluation program stored in the area is executed. Meanwhile, the test dedicated pin 2 is pulled up, the program ROM 3 is accessed.</p> |
