NEC 78K/0 Series User Manual page 99

RETI
[Instruction format]
[Operation]
[Operand]
None
[Flag]
Z AC
R R
[Description]
• This is a return instruction from the vectored interrupt.
• The data saved to the stack returns to the PC and the PSW, and the program returns from the interrupt service
routine.
• This instruction cannot be used for return from the software interrupt with the BRK instruction.
• 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)
except software interrupts can be acknowledged.
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 U12326EJ4V0UM
Return from Interrupt
Return from Hardware Vectored Interrupt
99