There are three alternative ways to disable the OCD system:
• Disable the OCDEN Fuse
• Disable the JTAGEN Fuse
• Write one to the JTD bit in MCUCR
11.12. Register Description
Atmel ATmega644A [DATASHEET]
Atmel-42716C-ATmega644A_Datasheet_Complete-10/2016
61
