A000047 Arduino, A000047 Datasheet - Page 110

• Manufacturer Part Number: A000047
• Description: MCU, MPU & DSP Development Tools Mega2560
• Manufacturer: Arduino
• Series: -r
• Type: MCUr

Specifications of A000047

• Processor To Be Evaluated: ATmega2560
• Interface Type: USB, I2C, SPI
• Dimensions: 4 in x 2.1 in
• Operating Supply Voltage: 5 V
• Contents: Board
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: ATmega2560

13.4
13.4.1
2549M–AVR–09/10
Register Description
MCUCR – MCU Control Register
• Bit 1 – IVSEL: Interrupt Vector Select
When the IVSEL bit is cleared (zero), the Interrupt Vectors are placed at the start of the Flash
memory. When this bit is set (one), the Interrupt Vectors are moved to the beginning of the Boot
Loader section of the Flash. The actual address of the start of the Boot Flash Section is deter-
mined by the BOOTSZ Fuses. Refer to the section
details. To avoid unintentional changes of Interrupt Vector tables, a special write procedure must
be followed to change the IVSEL bit (see
tion” on page
Bit
0x35 (0x55)
Read/Write
Initial Value
Assembly Code Example
C Code Example
1. Write the Interrupt Vector Change Enable (IVCE) bit to one.
2. Within four cycles, write the desired value to IVSEL while writing a zero to IVCE.
Move_interrupts:
void Move_interrupts(void)
{
uchar temp;
}
; Get MCUCR
in
mov r17, r16
; Enable change of Interrupt Vectors
ori r16, (1<<IVCE)
out MCUCR, r16
; Move interrupts to Boot Flash section
ori r16, (1<<IVSEL)
out MCUCR, r17
ret
/* Get MCUCR*/
temp = MCUCR;
/* Enable change of Interrupt Vectors */
MCUCR = temp|(1<<IVCE);
/* Move interrupts to Boot Flash section */
MCUCR = temp|(1<<IVSEL);
r16, MCUCR
109):
JTD
R/W
7
0
6
–
R
0
ATmega640/1280/1281/2560/2561
R
5
–
0
PUD
R/W
4
0
“Moving Interrupts Between Application and Boot Sec-
R
3
–
0
“Memory Programming” on page 335
R
2
–
0
IVSEL
R/W
1
0
IVCE
R/W
0
0
MCUCR
110
for