[215] QSPI: Reading QSPI registers after XIP might halt CPU

This anomaly applies to IC Rev. Engineering C, build codes QIAA-CA0, CKAA-CA0.

It was inherited from the previous IC revision Engineering B nRF52840.

Symptoms

CPU halts.

Conditions

Init and start QSPI, use XIP, then write to or read any QSPI register with an offset above 0x600.

Consequences

CPU halts.

Workaround

Trigger QSPI TASKS_ACTIVATE after XIP is used before accessing any QSPI register with an offset above 0x600.