ATmega325PA Atmel Corporation, ATmega325PA Datasheet - Page 61

• Manufacturer Part Number: ATmega325PA
• Manufacturer: Atmel Corporation

12.3
12.3.1
8285D–AVR–06/11
Register Description
MCUCR – MCU Control Register
ATmega165A/PA/325A/PA/3250A/PA/645A/P/6450A/P
Note:
• 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
Self-Programming” on page 266
• Bit 0 – IVCE: Interrupt Vector Change Enable
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 description in
Space” on page
Bit
0x35 (0x55)
Read/Write
Initial Value
1. Only available in the picoPower devices ATmega165PA/325PA/3250PA/645P/6450P.
JTD
R/W
7
0
60. See Code Example.
BODS
R
6
0
(1)
BODSE
for details.
R
5
0
(1)
PUD
R/W
4
0
”Moving Interrupts Between Application and Boot
”Boot Loader Support – Read-While-Write
R
3
–
0
R
2
–
0
IVSEL
R/W
1
0
IVCE
R/W
0
0
MCUCR
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