Several of the security devices, including CryptoAuthentication device like the ATECC508A, requires only an I2C interface to work, and they share the same package and pinouts. SAMC21N Xplained Pro has implemented 8-pad UDFN package ATECC508A-MAHDA-T device. Table 1 shows all the connections between the crypto device and the ATSAMC21N18A.
| Pin on footprint | SAMC21N pin | Function | Shared functionality |
|---|---|---|---|
| 1 | - | NC | - |
| 2 | - | NC | - |
| 3 | - | NC | - |
| 4 | - | GND | - |
| 5 | PA16 [SDA] | SERCOM1 PAD[0] I2C SDA | EXT2, EXT3, Shield, and 2EDBG IC |
| 6 | PA17 [SCL] | SERCOM1 PAD[1] I2C SCL | EXT2, EXT3, Shield, and 2EDBG IC |
| 7 | - | NC | - |
| 8 | - | VCC_TARGET_P3V3 | - |
| PADDLE | - | GND | - |