This HAL for ATSAMD51 has support for the NVM and the Smart EEPROM feature. Similar to the SAMD51, the SAMD21 has some flash reserved for EEPROM-like functionality, which can be written while the main program memory is read (called "Read-While-Write EEPROM Emulation" in the datasheet). It's only present on devices with <256KB of flash, and only on some variants (B, C, D, and L)
This HAL for ATSAMD51 has support for the NVM and the Smart EEPROM feature. Similar to the SAMD51, the SAMD21 has some flash reserved for EEPROM-like functionality, which can be written while the main program memory is read (called "Read-While-Write EEPROM Emulation" in the datasheet). It's only present on devices with <256KB of flash, and only on some variants (B, C, D, and L)