Rainbow Electronics ATmega128L - Manual (Page 55)

55
ATmega128(L)
2467B–09/01
Notes: 1. When the BOOTRST fuse is programmed, the device will jump to the Boot Loader
address at reset, see “Boot Loader Support – Read-While-Write Self-Programming”
on page 266.
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 address in
this table added to the start address of the boot Flash section.
3. The Interrupts on address $0030 - $0044 do not exist in ATmega103 compatibility
mode.
Table 24 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 loca-
tions. 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: The Boot Reset Address is shown in Table 113 on page 277. For the BOOTRST fuse “1”
means unprogrammed while “0” means programmed.
31 $003C (3) USART1, RX USART1, Rx Complete
32 $003E (3) USART1, UDRE USART1 Data Register Empty
33 $0040 (3) USART1, TX USART1, Tx Complete
34 $0042 (3) TWI 2-wire Serial Interface
35 $0044 (3) SPM READY Store Program Memory Ready
Table 24. Reset and Interrupt Vectors Placement
BOOTRST IVSEL Reset address Interrupt Vectors Start Address
1 0 $0000 $0002
1 1 $0000 Boot Reset Address + $0002
0 0 Boot Reset Address $0002
0 1 Boot Reset Address Boot Reset Address + $0002
Table 23. Reset and Interrupt Vectors (Continued)
Vector
No.
Program
Address (2) Source Interrupt Definition