chip

Fuse bit

Atmega328p UNO

fuse set UNO-1 UNO-1 note UNO-2   empty  
e 05   FD   FF  
h DE   DE   D9  
l FF   FF   62  
LB 0F bootloader area NOT visit-able ?      

Lock bit

  • BLB12 BLB11 - app to bootloader
  • BLB02 BLB01 - bootloader to app
  • LB2 LB1 - visit control to Flash, EEPROM, Fuse (hfuse, lfuse, efuse) and Boot Lock Bit

low fuse

  • bootloader area NOT visit-able - lfuse set to 0x0F
  • bootloader area visit-able - lfuse set to 0x3F

board

bootloarder

PROG

converter tools

legacy wiki page - https://w.electrodragon.com/w/Category:Arduino#Burning_bootloader

ISP pins

ICSP 6pins