[111] RAM: Retention in OFF mode is not controlled by RAM[n].POWER->SxRETENTION, but by RAM[n].POWER->SxPOWER

This anomaly applies to IC Rev. Engineering A, build codes QIAA-AA0.

Symptoms

Current consumption in OFF mode is higher than expected. RAM contents are retained in OFF mode when they should not be.

Conditions

Always.

Consequences

Cannot independently control RAM retention in OFF mode and power in ON mode.

Workaround

Use RAM[n].POWER->SxPOWER to control the retention in OFF mode and power in ON mode. Exercise caution when using this workaround, becausee the firmware requires a certain amount of RAM to be powered when waking from OFF mode (such as the RAM where the call stack is located), and RAM[n].POWER registers are retained registers.


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