4.4.1 UPDI Connection v1
This was the initial layout for the UPDI connection used by older programming tools (like the Atmel ICE).
The UPDI Connection v1 is a 100-mil 6-pin 2x3 header. Even though using only three pins for programming, it is recommended to use a 2x3 header since most programming tools using this connection are delivered with 100-mil 6-pin 2x3 connectors.
The following figure shows the recommendation for a UPDI connection to the device using the UPDI Connection v1.
The decoupling capacitor between VDD and GND must be placed as close to the pin pair as possible. Include the decoupling capacitor even if the UPDI connector is not included in the circuit.