12.10.7 On-chip Debug System

If the On-chip debug system is enabled by the OCDEN Fuse and the chip enters sleep mode, the main clock source is enabled and hence always consumes power. In the deeper sleep modes, this will contribute significantly to the total current consumption.

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