[115] RAM: RAM content cannot be trusted upon waking up from System ON Idle or System OFF mode

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

Symptoms

RAM not correctly retained.

Conditions

System ON Idle mode or System OFF is used with parts or all RAM retained.

Consequences

RAM not correctly retained.

Workaround

Apply the following code after any reset:
*(volatile uint32_t *)0x40000EE4 = ( (*(volatile uint32_t *)0x40000EE4 & 0x00000070) | // Keep bit 6:4
                                    (*(uint32_t *)0x10000258 & 0x0000000F) ); // Replace bit 3:0
 
This workaround has already been added into system_nrf52840.c file present in MDK 8.11.0 or later. This workaround increases the I_RAM current per 4 KB section from 20 nA to 30 nA.

Documentation feedback | Developer Zone | Subscribe | Updated 2017-04-21