Datasheet

64
2490R–AVR–02/2013
ATmega64(L)
When the BOOTRST Fuse is programmed and the Boot section size set to 8 Kbytes, the most
typical and general program setup for the Reset and Interrupt Vector Addresses is:
Address Labels Code Comments
.org 0x0002
0x0002 jmp EXT_INT0 ; IRQ0 Handler
0x0004 jmp EXT_INT1 ; IRQ1 Handler
... ... ... ;
0x0044 jmp SPM_RDY ; Store Program Memory Ready Handler
;
.org 0x7000
0x7000 RESET: ldi r16,high(RAMEND); Main program start
0x7001 out SPH,r16 ; Set Stack Pointer to top of RAM
0x7002 ldi r16,low(RAMEND)
0x7003 out SPL,r16
0x7004 sei ; Enable interrupts
0x7005 <instr> xxx
When the BOOTRST Fuse is programmed, the Boot section size set to 8 Kbytes and the IVSEL
bit in the MCUCR Register is set before any interrupts are enabled, the most typical and general
program setup for the Reset and Interrupt Vector Addresses is:
Address Labels Code Comments
;
.org 0x7000
0x7000 jmp RESET ; Reset handler
0x7002 jmp EXT_INT0 ; IRQ0 Handler
0x7004 jmp EXT_INT1 ; IRQ1 Handler
... ... ... ;
0x7044 jmp SPM_RDY ; Store Program Memory Ready Handler
0x7046 RESET: ldi r16,high(RAMEND); Main program start
0x7047 out SPH,r16 ; Set Stack Pointer to top of RAM
0x7048 ldi r16,low(RAMEND)
0x7049 out SPL,r16
0x704A sei ; Enable interrupts
0x704B <instr> xxx
Moving Interrupts
Between Application
and Boot Space
The General Interrupt Control Register controls the placement of the Interrupt Vector table.
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
Bit 76543210
0x35 (0x55)
SRE SRW10 SE SM1 SM0 SM2 IVSEL IVCE MCUCR
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial Value00000000