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RETI

Return from interrupt.
Function: PClow <- (SP); PChigh <- (SP + 1); SP <- SP + 2
 
Format:
1110 1101
 
byte 1: ED
 
0100 1101
 
byte 2: 4D
 
Description: The program counter is popped off the stack as described for the POP instructions. This instruction is recognized by Zilog peripheral devices as the end of a peripheral service routine so as to allow proper control of nested priority interrupts. An EI instruction must be executed prior to RETI in order to re-enable interrupts.
 
Data Flow:
 
Timing: 4 M cycles; 14 T states: 7 usec @ 2 MHz
 
Addressing Mode: indirect
 
Flags:
 
(no effect)
 
Example:
RETI

OBJECT CODE
Before:
 
After: