BRK (BReaK)

Push (PC >> 8); Push (PC & 0xFF); Push (Flags | B); Flags |= I = 1; PC = [IRQ Vector]

BRK performs an interrupt request by pushing the program counter (PC) and processor status (Flags) onto the stack, and then setting the program counter to the address of the interrupt vector. It also sets the Interrupt Disable (I) flag to 1.

Addressing Modes

Mode	Syntax	Bytes	Cycles
Implied	BRK	00	7

Flags Affected

All flags are affected.

Examples

Interrupt Handling

    ; initialize interrupt vector
    LDA #<IRQ_HANDLER
    STA $FFFE
    LDA #>IRQ_HANDLER
    STA $FFFF
    ; enable IRQ interrupts
    SEI

See Also

• RTI (ReTurn from Interrupt)

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