[102] CCM: Operation fails when CCM MAC length is set to 0

nRF54LM20A Revision 1 Errata

This anomaly applies to Revision 1, build code PAAA-B00.

It was inherited from the previous SoC revision Engineering B.

Symptoms

CCM might stop and not complete its operation when CONFIG.MACLEN=M0 is used.

Conditions

CCM is used for encryption without authentication and under some combinations of DMA address alignment.

Consequences

CCM stalls and does not generate the END or ERROR events.

Workaround

Set MODE.MACLEN=M4 and ignore the MAC written by CCM.