Interrupt Servicing Operation; Non-Maskable Interrupt Acknowledgment Operation - NEC switch User Manual

Nec user's manua switch
Table of Contents

Advertisement

11.4 Interrupt Servicing Operation

11.4.1 Non-maskable interrupt acknowledgment operation

The non-maskable interrupt is unconditionally acknowledged even when interrupts are disabled. It is not subject
to interrupt priority control and takes precedence over all other interrupts.
When the non-maskable interrupt request is acknowledged, the PSW and PC are saved to the stack in that order,
the IE flag is reset to 0, the contents of the vector table are loaded to the PC, and then program execution branches.
Caution
During non-maskable interrupt service program execution, do not input another non-maskable
interrupt request; if it is input, the service program will be interrupted and the new interrupt
request will be acknowledged.
CHAPTER 11
INTERRUPT FUNCTIONS
User's Manual U12978EJ3V0UD
171

Advertisement

Table of Contents
loading

Table of Contents