CHAPTER 5 EXPLANATION OF INSTRUCTIONS
User’s Manual U11047EJ3V0UM00
96
RETI
Return from Interrupt
Return from Hardware Vectored Interrupt
[Instruction format]
RETI
[Operation]
PC
L
←
(SP),
PC
H
←
(SP + 1),
PSW
←
(SP + 2),
SP
←
SP + 3,
NMIS
←
0
[Operand]
None
[Flag]
Z
AC
CY
R
R
R
[Description]
•
This is a return instruction from the vectored interrupt.
•
The data saved in the stack returns to the PC and PSW, and the program returns from the interrupt service
routine.
•
None of interrupts are acknowledged between this instruction and the next instruction to be executed.
•
The NMIS flag is set to 1 by acknowledgment of a non-maskable interrupt, and cleared to 0 by the RETI
instruction.
[Caution]
When the return from non-maskable interrupt servicing is performed by an instruction other than the RETI
instruction, the NMIS flag is not cleared to 0, and therefore no interrupts (including non-maskable interrupts) can
be acknowledged.
Summary of Contents for 78K/0S Series
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