8.9 SIGROW - Signature Row

The content of the Signature Row (SIGROW) fuses is pre-programmed and cannot be altered. SIGROW holds the device ID, serial number, and calibration values.

All the AVR64EA28/32/48 devices have a three-byte device ID that identifies the device. This device ID can be read using the UPDI interface, even when the device is locked. The three bytes reside in the Signature Row. The signature bytes are given in the following table.