Interrupt Processing: Non Maskable Interrupt

Non maskable interrupt
Non maskable interrupt

Non maskable interrupt cannot be disabled.
If there is an interrupt request, the CPU will perform the interrupt processing unconditionally.
The non maskable interrupt is used for emergency processing, for example, data backup processing such as power outage processing.

There is a watchdog timer as the non maskable interrupt.
The watchdog timer checks whether the microcontroller is operating normally or not.
When an abnormal operation is detected, it generates the watchdog timer interrupt to notify the error to the CPU or resets the CPU. 

Reset
Reset

Reset
The microcontroller can be reset generally when the power is turned on.
Reset returns the microcontroller configurations to the initial state.
In reset, the program will run from the beginning.

Chapter 4 Toshiba Microcontrollers, Example of Core (TLCS-870/C1)

Overall Configuration of the CPU
Overall Configuration of the CPU: CPU Core (1)
Overall Configuration of the CPU: CPU Core (2)
Overall Configuration of the CPU: Program Counter
Overall Configuration of the CPU: General-purpose Register
Overall Configuration of the CPU: PSW (Flag)
Overall Configuration of the CPU: Stack and Stack Pointer
Interrupt Processing
Interrupt Processing: Interrupt Type
Interrupt Processing: Maskable Interrupt