NEC 78K/0S Series User Manual page 96

RETI
[Instruction format]
[Operation]
[Operand]
None
[Flag]
Z AC
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.
96
CHAPTER 5 EXPLANATION OF INSTRUCTIONS
RETI
← (SP),
PC
L
← (SP + 1),
PC
H
PSW ← (SP + 2),
← SP + 3,
SP
NMIS ← 0
CY
R
User's Manual U11047EJ3V0UM00
Return from Interrupt
Return from Hardware Vectored Interrupt