| 摘要 |
PURPOSE: To set an external system to a fail-safe side without providing a fail-safe circuit on the outside of a microcomputer and to reduce the number of the parts of a system. CONSTITUTION: The input/output port 5 of this microcomputer 1 is provided with a first register 10 and a second register 11 for setting an output state from a CPU based on the chip selection output of an address decoder and a selector 14 for selecting the output state set in the first register 10 or the output state set in the second register 11 based on selection signals from the outside and outputting it to an output terminal. |
