42.8.5 Interrupt Flag Status and Clear

This flag is cleared by writing a '1' to it.

This flag is set when GHASH value is available on the Galois Hash Registers (GHASHx) in GCM mode.

Writing a '0' to this bit has no effect.

This flag is also automatically cleared in the following cases.

1. Manual encryption/decryption occurs (START in CTRLB register).
2. Reading from the GHASHx register.

This flag is cleared by writing a '1' to it.

This flag is set when encryption/decryption is complete and valid data is available on the Data Register.

Writing a '0' to this bit has no effect.

This flag is also automatically cleared in the following cases:

1. Manual encryption/decryption occurs (START in CTRLA register). (This feature is needed only if we do not support double buffering of INDATA registers).
2. Reading from the data register (INDATAx) when LOD = 0.
3. Writing into the data register (INDATAx) when LOD = 1.
4. Reading from the Hash Key register (HASHKEYx).