RTS (ReTurn from Subroutine)¶

PC = Pop(); PC = (PC | (Pop() << 8)) + 1

RTS performs a return from subroutine by retrieving the address of the next instruction from the stack and setting the program counter (PC) to that address plus one.

Addressing Modes¶

Mode	Syntax	Bytes	Cycles
Implied	RTS	`60`	6

Flags Affected¶

None.

Examples¶

Simple Subroutine Call and Return¶

    JSR SUBROUTINE ; jump to subroutine
    ; code to execute after subroutine returns
    RTS            ; return from subroutine
SUBROUTINE:
    ; code for the subroutine
    RTS            ; return to the caller

Storing the Return Address in a Zero Page Location¶

    LDA #<SUBROUTINE   ; load the low byte of the subroutine address into A
    PHA                ; push it onto the stack
    LDA #>SUBROUTINE   ; load the high byte of the subroutine address into A
    PHA                ; push it onto the stack
    JMP (ZP_LOCATION)  ; jump to the address stored in a zero page location
ZP_LOCATION:
    .byte SUBROUTINE   ; the low byte of the subroutine address
    .byte SUBROUTINE>>8 ; the high byte of the subroutine address
SUBROUTINE:
    ; code for the subroutine
    RTS                ; return to the caller