Description:

Sets the Global Interrupt flag (I) in SREG (status register). The instruction following SEI will be executed before any pending interrupts.

Operation:

(i) I ← 1

Syntax: Operands: Program Counter:

(i) SEI None PC ← PC + 1

16-bit Opcode:

1001

0100

0111

1000

Status Register (SREG) and Boolean Formula:

I

T

H

S

V

N

Z

C

1

-

-

-

-

-

-

-

I: 1

Global Interrupt flag set

Example:

sei ; set global interrupt enable
sleep ; enter sleep, waiting for interrupt
; note: will enter sleep before any pending interrupt(s)

Words: 1 (2 bytes)

Cycles: 1