Reti – NEC 78K/0 Series User Manual
Page 99
CHAPTER 5 EXPLANATION OF INSTRUCTIONS
99
User's Manual U12326EJ4V0UM
Return from Interrupt
RETI
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 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.