External Interrupt Extension and Software Implementation of Multi-interrupt Priority for MCS-51 Single Chip Microcomputer

摘要

The series of MCS 51 Single Chip Microcomputer (SCM) only have two external interrupts and two interrupt priorities. This paper introduces three methods for the extension of external interrupts. It also specifies the program of each extension through the employment of software. This method can be applied to the system requiring several external interrupts and multi-level interrupt nestings.