Datasheet

ATmega164A/PA/324A/PA/644A/PA/1284/P
 2018 Microchip Technology Inc. Data Sheet Complete DS40002070A-page 70
Notes: 1. When the BOOTRST Fuse is programmed, the device will jump to the Boot Loader address at reset, see
”Memory programming” on page 295.
2. When the IVSEL bit in MCUCR is set, Interrupt Vectors will be moved to the start of the Boot Flash Section.
The address of each Interrupt Vector will then be the address in this table added to the start address of the
Boot Flash Section.
3. Applies only to ATmega1284P.
Table 12-2 shows reset and Interrupt Vectors placement for the various combinations of BOOTRST and IVSEL
settings. If the program never enables an interrupt source, the Interrupt Vectors are not used, and regular
program code can be placed at these locations. This is also the case if the Reset Vector is in the Application
section while the Interrupt Vectors are in the Boot section or vice versa.
Note: 1. The Boot Reset Address is shown in Table 26-10 on page 290. For the BOOTRST Fuse “1” means
unprogrammed while “0” means programmed.
27 $0034 TWI two-wire Serial Interface
28 $0036 SPM_READY Store Program Memory Ready
29 $0038 USART1_RX USART1 Rx Complete
30 $003A USART1_UDRE USART1 Data Register Empty
31 $003C USART1_TX USART1 Tx Complete
32 $003E TIMER3_CAPT
(3)
Timer/Counter3 Capture Event
33 $0040 TIMER3_COMPA
(3)
Timer/Counter3 Compare Match A
34 $0042 TIMER3_COMPB
(3)
Timer/Counter3 Compare Match B
35 $0044 TIMER3_OVF
(3)
Timer/Counter3 Overflow
Table 12-2. Reset and Interrupt Vectors placement
(1)
BOOTRST IVSEL Reset Address Interrupt Vectors Start Address
1 0 0x0000 0x0002
1 1 0x0000 Boot Reset Address + 0x0002
0 0 Boot Reset Address 0x0002
0 1 Boot Reset Address Boot Reset Address + 0x0002
Table 12-1. Reset and Interrupt Vectors
Vector
no.
Program
address
(2)
Source Interrupt definition