User manual

Note: Some precautions regarding the RESET line must be taken to ensure proper communication over the debugWIRE interface. If there
is a pull-up on the RESET line, this resistor must be larger than 10Kohm, and there should be no capacitive load. The pull-up resistor is
not required for debugWIRE functionality. Other logic connected to the RESET line should be removed.
Note
It's not possible to use the debugWIRE Interface if the lockbits on the target AVR are programmed. Always be sure that the lockbits are
cleared before programming the DWEN fuse and never set the lockbits while the DWEN fuse is programmed. If both the debugWIRE
enable fuse (DWEN) and lockbits are set, one can use High Voltage Programming to do a chip erase, hence clear the lockbits. When the
lockbits are cleared the debugWIRE Interface will be re-enabled.
Note
The ISP Interface is only capable of reading fuses, signature and do a chip erase when the DWEN fuse is unprogrammed.