ATmega48/88/168
0x01D
0x01E
out
sei
SPL,r16
; Enable interrupts
0x01F
...
<instr> xxx
... ...
...
When the BOOTRST Fuse is unprogrammed, the Boot section size set to 2K bytes 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 in
ATmega88 is:
Address Labels Code
Comments
0x000
RESET: ldi
out
r16,high(RAMEND); Main program start
0x001
RAM
SPH,r16
; Set Stack Pointer to top of
0x002
ldi
r16,low(RAMEND)
SPL,r16
0x003
0x004
out
sei
; Enable interrupts
0x005
;
<instr> xxx
.org 0xC01
0xC01
rjmp
rjmp
...
EXT_INT0
EXT_INT1
...
; IRQ0 Handler
0xC02
; IRQ1 Handler
...
;
0xC19
rjmp
SPM_RDY
; Store Program Memory Ready
Handler
When the BOOTRST Fuse is programmed and the Boot section size set to 2K bytes, the
most typical and general program setup for the Reset and Interrupt Vector Addresses in
ATmega88 is:
Address Labels Code
Comments
.org 0x001
0x001
0x002
...
rjmp
rjmp
...
EXT_INT0
EXT_INT1
...
; IRQ0 Handler
; IRQ1 Handler
;
0x019
rjmp
SPM_RDY
; Store Program Memory Ready
Handler
;
.org 0xC00
0xC00
RESET: ldi
r16,high(RAMEND); Main program start
0xC01
RAM
out
SPH,r16
; Set Stack Pointer to top of
0xC02
ldi
r16,low(RAMEND)
SPL,r16
0xC03
0xC04
out
sei
; Enable interrupts
0xC05
<instr> xxx
55
2545D–AVR–07/04