[37] RADIO: Encryption engine is slow by default.

This anomaly applies to IC Rev. Engineering A, build codes QFAA-AA0, QFAA-AC0, CGAA-AA0.

Symptoms

When Radio encryption is enabled, TX or RX packets are sometimes corrupted. Encryption/decryption functions (ECB, AAR, and CCM) take longer than documented.

Conditions

Always.

Consequences

Radio packet error. Encryption takes longer time.

Workaround

Add the following code at the start of your program:

*(volatile uint32_t *)0x400005A0 = 0x3; 
This code has already been added into system_nrf52.c.