Two UPDI headers (J3 and J4) are used for programming and debugging the two
on-board MCUs (ATtiny1617 and ATtiny416), which are not mounted on the board.
Table 4-3. UPDI header for ATtiny1617
(J3)| Pin on UPDI header | Pin on ATtiny1617-MNR | Function |
|---|
| 1 | - | Not Connected |
| 2 | 3 | GND |
| 3 | 23 | UPDI |
| 4 | 4 | VCC |
| 5 | - | Not Connected |
| 6 | - | Not Connected |
| 7 | - | Not Connected |
| 8 | - | Not Connected |
| 9 | - | Not Connected |
| 10 | - | Not Connected |
Table 4-4. UPDI header for ATtiny416
(J4)| Pin on UPDI header | Pin on ATtiny416-MNR | Function |
|---|
| 1 | - | Not Connected |
| 2 | 3 | GND |
| 3 | 19 | UPDI |
| 4 | 4 | VCC |
| 5 | - | Not Connected |
| 6 | - | Not Connected |
| 7 | - | Not Connected |
| 8 | - | Not Connected |
| 9 | - | Not Connected |
| 10 | - | Not Connected |
