SEI

Set Interrupt Disable Flag

Opcode: SEI Operation: 1 → I Status Register:

SEI (Set Interrupt Disable Flag) sets the Interrupt Flag in the Processor Status Register by setting the 2nd bit 1. To clear the interrupt disable flag, use CLI.

Operation

This pseudo C code shows how the SEI opcode functions when it is executed.

SET_INTERRUPT((1));           // Set the 2nd bit of the processor status to 1.

Addressing Modes

Addressing Mode	Assembly Language Form	Opcode	# Bytes	# Cycles
Implied	SEI	78	1	2