The Program and Debug Interface (PDI) is an Atmel proprietary interface for external programming and on-chip debugging of a device. PDI Physical is a 2-pin interface providing a bi-directional half-duplex synchronous communication with the target device.
When designing an application PCB which includes an AVR with the PDI interface, the pinout shown in Figure 1 should be used. The 6-pin adapter provided with the Atmel AVR JTAGICE mkII kit can then be used to connect the JTAGICE mkII probe to the application PCB.
The pinout shown above is compatible with the Atmel STK600, Atmel AVR ONE!, AVR Dragon™, and future tools with PDI interface. The JTAGICE mkII supports this pinout using the AVR XMEGA PDI adapter for JTAGICE mkII (shipped with the kit or available from your local Atmel representative.)