AT90USB82_0811 Datasheet, PDF (66/306 Pages) ATMEL Corporation – 8-bit Microcontroller with 8/16K Bytes of ISP Flash and USB Controller

The IVCE bit must be written to logic one to enable change of the IVSEL bit. IVCE is cleared by
hardware four cycles after it is written or when IVSEL is written. Setting the IVCE bit will disable
interrupts, as explained in the IVSEL description above. See Code Example below.
Assembly Code Example
Move_interrupts:
; Enable change of Interrupt Vectors
ldi r16, (1<<IVCE)
out MCUCR, r16
; Move interrupts to Boot Flash section
ldi r16, (1<<IVSEL)
out MCUCR, r16
ret
C Code Example
void Move_interrupts(void)
{
/* Enable change of Interrupt Vectors */
MCUCR = (1<<IVCE);
/* Move interrupts to Boot Flash section */
MCUCR = (1<<IVSEL);
}
66 AT90USB82/162
7707E–AVR–11/08