nrf51822 advertising timeout sleep RAM retention

[mm81]

Hello I would like to know when nrf51822 (SDK v12.3 with SD S130 ) advertising timeout and system goes to sleep , how could I retain the ram data so the MCU could work properly when it is woke up by other event? Thanks.

[mm81]

i have put the following code below trying to prevent data loss after advertising timeout but failed...any idea?? // Switch ON both RAM banks when in system OFF mode NRF_POWER->RAMON |= (POWER_RAMON_OFFRAM0_RAM0On << POWER_RAMON_OFFRAM0_Pos) | (POWER_RAMON_OFFRAM1_RAM1On << POWER_RAMON_OFFRAM1_Pos);