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Maxim Integrated DS4830A Optical Microcontroller User Manual

Page 221

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DS4830A User’s Guide

221

RETI

Return from Interrupt


Description:

RETI pops a single word from the stack (@SP) into the Instruction Pointer (IP) and
decrements the stack pointer (SP). Additionally, RETI returns the interrupt logic to a state in
which it can acknowledge additional interrupts.


Status Flags:

None


Operation:

IP

 @SP--

INS

 0


Encoding:

15

0

1000

1100

1000

1101


Example(s):

see RET


RETI C / RETI NC

Conditional Return from Interrupt on Status Flag

RETI Z / RETI NZ

RETI S


Description:

Performs conditional return from interrupt (RETI) based upon the state of a specific
processor status flag. RETI C returns if the Carry flag is set while RETI NC returns if the
Carry flag is clear. RETI Z returns if the Zero flag is set while RETI NZ returns if the Zero
flag is clear. RETI S returns if the Sign flag is set. See RETI for additional information on
the return from interrupt operation.

Status Flags:

None



RETI C
Operation:

C=1: IP

 @SP--

INS

 0

C=0: IP

 IP + 1


Encoding:

15

0

1010

1100

1000

1101


Example(s):

RETI C

; C=1, return from interrupt (RETI) is performed.



RETI NC
Operation:

C=0: IP

 @SP--

INS

 0

C=1: IP

 IP +1


Encoding:

15

0

1110

1100

1000

1101


Example(s):

RETI NC

; C=1, return from interrupt (RETI) does not occur