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What does the CPU do if an interrupt that is not used occurs?

Latest Updated:12/01/2011

Question:

If an interrupt that is not used occurs due to a bug or a CPU hardware failure, what does the CPU do?

Answer:

It is impossible to positively state what operation will result when an unused interrupt is received, because when the CPU acknowledges an interrupt, it reads the branch destination address (vector) from the vector table data determined for each interrupt, and branches to that address.
Then the CPU executes the code written at that address as an instruction.
So the type of operation performed depends on the code that is read.
Suitable Products
RL78 Family
78K Family