When enabled, the debugWIRE interface takes control of the device's /RESET pin,
which makes it mutually exclusive to the SPI interface, which also needs this pin. When
enabling and disabling the debugWIRE module, follow one of these two approaches:
- Let Atmel Studio take care of things (recommended)
- Set and clear DWEN manually (exercise caution, advanced users only!)
Important: When manipulating DWEN
manually, it is important that the SPIEN fuse remains set to avoid having to use
High-Voltage programming.
Figure 1. Understanding debugWIRE and the
DWEN Fuse