SYSTEM ON mode: RAM retention RTC VS NO RAM retention RTC

[826896167]

void func_ram_power_off(void)
{
uint8_t i = 0;

for(i = 0; i < 8; i++)
{
NRF_POWER->RAM[i].POWERCLR = (POWER_RAM_POWER_S0POWER_Off << POWER_RAM_POWER_S0POWER_Pos) |
(POWER_RAM_POWER_S1POWER_Off << POWER_RAM_POWER_S1POWER_Pos) |
(POWER_RAM_POWER_S0RETENTION_Off << POWER_RAM_POWER_S0RETENTION_Pos) |
(POWER_RAM_POWER_S1RETENTION_Off << POWER_RAM_POWER_S1RETENTION_Pos);
}


}

/**
* @brief Function for application main entry.
*/
int main(void)
{
leds_config();
lfclk_config();
rtc_config();

//func_ram_power_off();
#if 0
NRF_POWER->RAMON |= (POWER_RAMON_OFFRAM0_RAM0On << POWER_RAMON_OFFRAM0_Pos) |
(POWER_RAMON_OFFRAM1_RAM1On << POWER_RAMON_OFFRAM1_Pos);
#endif
__DSB();
__NOP();

while (true)
{
__WFE();

}
}

when my code func_ram_power_off() enable is NO RAM retention,func_ram_power_off() disable is  RAM retention,but the power same is 1.6uA,

why? 

thanks you!

[Jared]

Hi there,

Can you use the debugger in SES and show me screenshot of the RAM[i].POWERCLR registers, as I've shown below:

regards

Jared

[826896167]

NRF_POWER->RAM[i].POWERCLR = (POWER_RAM_POWER_S0POWER_Off << POWER_RAM_POWER_S0POWER_Pos) |
(POWER_RAM_POWER_S1POWER_Off << POWER_RAM_POWER_S1POWER_Pos) |
(POWER_RAM_POWER_S0RETENTION_Off << POWER_RAM_POWER_S0RETENTION_Pos) |
(POWER_RAM_POWER_S1RETENTION_Off << POWER_RAM_POWER_S1RETENTION_Pos);

or 

NRF_POWER->RAM[i].POWERCLR = 0x03FF；

the result  NRF_POWER->RAM[i].POWERCLR is 0x0000；my chip is nrf52832，i  want to kown my code is ok?? 

or how to do it(RAM ON/OFF)?

thanks you!

[Jared]

Hi,

RAM retention is by default OFF.  

826896167 said:

NRF_POWER->RAM[i].POWERCLR = (POWER_RAM_POWER_S0POWER_Off << POWER_RAM_POWER_S0POWER_Pos) |
(POWER_RAM_POWER_S1POWER_Off << POWER_RAM_POWER_S1POWER_Pos) |
(POWER_RAM_POWER_S0RETENTION_Off << POWER_RAM_POWER_S0RETENTION_Pos) |
(POWER_RAM_POWER_S1RETENTION_Off << POWER_RAM_POWER_S1RETENTION_Pos);

You're mixing the correct bitfields, the ones that you're using is for the POWER register not the POWERCLR register. The correct code for testing retention off versus retention on:

#include <stdbool.h>
#include <stdint.h>
#include "nrf_delay.h"
#include "boards.h"

//#define POWER_OFF_RETENTION_OFF
#define POWER_ON_RETENTION_ON
//#define POWER_ON_RETENTION_OFF



  int main(void)

  {

    for(int i = 0; i <= 8; i++)

    {
      #ifdef POWER_OFF_RETENTION_OFF
      NRF_POWER->RAM[i].POWERCLR = (POWER_RAM_POWERCLR_S0POWER_Off << POWER_RAM_POWERCLR_S0POWER_Pos) |
      (POWER_RAM_POWERCLR_S1POWER_Off << POWER_RAM_POWERCLR_S1POWER_Pos) |
      (POWER_RAM_POWERCLR_S0RETENTION_Off << POWER_RAM_POWERCLR_S0RETENTION_Pos) |
      (POWER_RAM_POWERCLR_S1RETENTION_Off << POWER_RAM_POWERCLR_S1RETENTION_Pos);

      #endif

      #ifdef POWER_ON_RETENTION_ON
      
      NRF_POWER->RAM[i].POWER = (POWER_RAM_POWER_S0POWER_On << POWER_RAM_POWER_S0POWER_Pos) |
      (POWER_RAM_POWER_S1POWER_On << POWER_RAM_POWER_S1POWER_Pos) |
      (POWER_RAM_POWER_S0RETENTION_On << POWER_RAM_POWER_S0RETENTION_Pos) |
      (POWER_RAM_POWER_S1RETENTION_On << POWER_RAM_POWER_S1RETENTION_Pos);

      #endif

      #ifdef POWER_ON_RETENTION_OFF
      
      NRF_POWER->RAM[i].POWER = (POWER_RAM_POWER_S0POWER_On << POWER_RAM_POWER_S0POWER_Pos) |
      (POWER_RAM_POWER_S1POWER_On << POWER_RAM_POWER_S1POWER_Pos) |
      (POWER_RAM_POWER_S0RETENTION_Off << POWER_RAM_POWER_S0RETENTION_Pos) |
      (POWER_RAM_POWER_S1RETENTION_Off << POWER_RAM_POWER_S1RETENTION_Pos);
      #endif



    }
     //Go to System Off sleep
     NRF_POWER->SYSTEMOFF = 1;

    while(true)
    {}

  }

best regards
Jared