nRF52840-PDK RAM Retention do not work

[Alex_Huang]

Hi everyone, 

I am using the nRF52840-PDK and nRF5_SDK_17.1.0_ddde560, And trying to enter System Off modes with no RAM Retention.

I use the ram_retention example from SDK, ram retention suppose to turn on and off by changing the POWER_RAM_POWER_S[i]RETENTION_On / POWER_RAM_POWER_S[i]RETENTION_Off ( i=0~15 ) right? But the result doesn't change at all.

From

NRF_POWER->RAM[0].POWERSET = (POWER_RAM_POWER_S0POWER_On << POWER_RAM_POWER_S0POWER_Pos)      |
                            (POWER_RAM_POWER_S1POWER_On      << POWER_RAM_POWER_S1POWER_Pos)      |
                            (POWER_RAM_POWER_S2POWER_On      << POWER_RAM_POWER_S2POWER_Pos)      |
                            (POWER_RAM_POWER_S3POWER_On      << POWER_RAM_POWER_S3POWER_Pos)      |
                            (POWER_RAM_POWER_S4POWER_On      << POWER_RAM_POWER_S4POWER_Pos)      |
                            (POWER_RAM_POWER_S5POWER_On      << POWER_RAM_POWER_S5POWER_Pos)      |
                            (POWER_RAM_POWER_S6POWER_On      << POWER_RAM_POWER_S6POWER_Pos)      |
                            (POWER_RAM_POWER_S7POWER_On      << POWER_RAM_POWER_S7POWER_Pos)      |
                            (POWER_RAM_POWER_S8POWER_On      << POWER_RAM_POWER_S8POWER_Pos)      |
                            (POWER_RAM_POWER_S9POWER_On      << POWER_RAM_POWER_S9POWER_Pos)      |
                            (POWER_RAM_POWER_S10POWER_On     << POWER_RAM_POWER_S10POWER_Pos)     |
                            (POWER_RAM_POWER_S11POWER_On     << POWER_RAM_POWER_S11POWER_Pos)     |
                            (POWER_RAM_POWER_S12POWER_On     << POWER_RAM_POWER_S12POWER_Pos)     |
                            (POWER_RAM_POWER_S13POWER_On     << POWER_RAM_POWER_S13POWER_Pos)     |
                            (POWER_RAM_POWER_S14POWER_On     << POWER_RAM_POWER_S14POWER_Pos)     |
                            (POWER_RAM_POWER_S15POWER_On     << POWER_RAM_POWER_S15POWER_Pos)     |
                            (POWER_RAM_POWER_S0RETENTION_On  << POWER_RAM_POWER_S0RETENTION_Pos)  |
                            (POWER_RAM_POWER_S1RETENTION_On  << POWER_RAM_POWER_S1RETENTION_Pos)  |
                            (POWER_RAM_POWER_S2RETENTION_On  << POWER_RAM_POWER_S2RETENTION_Pos)  |
                            (POWER_RAM_POWER_S3RETENTION_On  << POWER_RAM_POWER_S3RETENTION_Pos)  |
                            (POWER_RAM_POWER_S4RETENTION_On  << POWER_RAM_POWER_S4RETENTION_Pos)  |
                            (POWER_RAM_POWER_S5RETENTION_On  << POWER_RAM_POWER_S5RETENTION_Pos)  |
                            (POWER_RAM_POWER_S6RETENTION_On  << POWER_RAM_POWER_S6RETENTION_Pos)  |
                            (POWER_RAM_POWER_S7RETENTION_On  << POWER_RAM_POWER_S7RETENTION_Pos)  |
                            (POWER_RAM_POWER_S8RETENTION_On  << POWER_RAM_POWER_S8RETENTION_Pos)  |
                            (POWER_RAM_POWER_S9RETENTION_On  << POWER_RAM_POWER_S9RETENTION_Pos)  |
                            (POWER_RAM_POWER_S10RETENTION_On << POWER_RAM_POWER_S10RETENTION_Pos) |
                            (POWER_RAM_POWER_S11RETENTION_On << POWER_RAM_POWER_S11RETENTION_Pos) |
                            (POWER_RAM_POWER_S12RETENTION_On << POWER_RAM_POWER_S12RETENTION_Pos) |
                            (POWER_RAM_POWER_S13RETENTION_On << POWER_RAM_POWER_S13RETENTION_Pos) |
                            (POWER_RAM_POWER_S14RETENTION_On << POWER_RAM_POWER_S14RETENTION_Pos) |
                            (POWER_RAM_POWER_S15RETENTION_On << POWER_RAM_POWER_S15RETENTION_Pos);

Change to

NRF_POWER->RAM[0].POWERSET = (POWER_RAM_POWER_S0POWER_On << POWER_RAM_POWER_S0POWER_Pos)      |
                            (POWER_RAM_POWER_S1POWER_On      << POWER_RAM_POWER_S1POWER_Pos)      |
                            (POWER_RAM_POWER_S2POWER_On      << POWER_RAM_POWER_S2POWER_Pos)      |
                            (POWER_RAM_POWER_S3POWER_On      << POWER_RAM_POWER_S3POWER_Pos)      |
                            (POWER_RAM_POWER_S4POWER_On      << POWER_RAM_POWER_S4POWER_Pos)      |
                            (POWER_RAM_POWER_S5POWER_On      << POWER_RAM_POWER_S5POWER_Pos)      |
                            (POWER_RAM_POWER_S6POWER_On      << POWER_RAM_POWER_S6POWER_Pos)      |
                            (POWER_RAM_POWER_S7POWER_On      << POWER_RAM_POWER_S7POWER_Pos)      |
                            (POWER_RAM_POWER_S8POWER_On      << POWER_RAM_POWER_S8POWER_Pos)      |
                            (POWER_RAM_POWER_S9POWER_On      << POWER_RAM_POWER_S9POWER_Pos)      |
                            (POWER_RAM_POWER_S10POWER_On     << POWER_RAM_POWER_S10POWER_Pos)     |
                            (POWER_RAM_POWER_S11POWER_On     << POWER_RAM_POWER_S11POWER_Pos)     |
                            (POWER_RAM_POWER_S12POWER_On     << POWER_RAM_POWER_S12POWER_Pos)     |
                            (POWER_RAM_POWER_S13POWER_On     << POWER_RAM_POWER_S13POWER_Pos)     |
                            (POWER_RAM_POWER_S14POWER_On     << POWER_RAM_POWER_S14POWER_Pos)     |
                            (POWER_RAM_POWER_S15POWER_On     << POWER_RAM_POWER_S15POWER_Pos)     |
                            (POWER_RAM_POWER_S0RETENTION_Off  << POWER_RAM_POWER_S0RETENTION_Pos)  |
                            (POWER_RAM_POWER_S1RETENTION_Off  << POWER_RAM_POWER_S1RETENTION_Pos)  |
                            (POWER_RAM_POWER_S2RETENTION_Off  << POWER_RAM_POWER_S2RETENTION_Pos)  |
                            (POWER_RAM_POWER_S3RETENTION_Off  << POWER_RAM_POWER_S3RETENTION_Pos)  |
                            (POWER_RAM_POWER_S4RETENTION_Off  << POWER_RAM_POWER_S4RETENTION_Pos)  |
                            (POWER_RAM_POWER_S5RETENTION_Off  << POWER_RAM_POWER_S5RETENTION_Pos)  |
                            (POWER_RAM_POWER_S6RETENTION_Off  << POWER_RAM_POWER_S6RETENTION_Pos)  |
                            (POWER_RAM_POWER_S7RETENTION_Off  << POWER_RAM_POWER_S7RETENTION_Pos)  |
                            (POWER_RAM_POWER_S8RETENTION_Off  << POWER_RAM_POWER_S8RETENTION_Pos)  |
                            (POWER_RAM_POWER_S9RETENTION_Off  << POWER_RAM_POWER_S9RETENTION_Pos)  |
                            (POWER_RAM_POWER_S10RETENTION_Off << POWER_RAM_POWER_S10RETENTION_Pos) |
                            (POWER_RAM_POWER_S11RETENTION_Off << POWER_RAM_POWER_S11RETENTION_Pos) |
                            (POWER_RAM_POWER_S12RETENTION_Off << POWER_RAM_POWER_S12RETENTION_Pos) |
                            (POWER_RAM_POWER_S13RETENTION_Off << POWER_RAM_POWER_S13RETENTION_Pos) |
                            (POWER_RAM_POWER_S14RETENTION_Off << POWER_RAM_POWER_S14RETENTION_Pos) |
                            (POWER_RAM_POWER_S15RETENTION_Off << POWER_RAM_POWER_S15RETENTION_Pos);

It really confuse me, please help.

Thanks.

[Kenneth]

Hello,

The nRF52840-PDK (Preview DK) was only available for a short period of time while the nRF52840 was undergoing qualification, test, and quite a lot of improvement were done in hardware before the final revision was relased to production. I am sorry to say, but the nRF52840-PDK is not supported or recommended for quite some time, please order an nRF52840-DK from a Nordic distributor.

Best regards,
Kenneth

[Alex_Huang]

Sorry for bothering again, I have another question, if i get the nRF52840-DK, the System Off modes with no RAM Retention setting code should be like :

for(uint8_t i = 0; i < 9; i++)
{
    NRF_POWER->RAM[i].POWERSET = (POWER_RAM_POWER_S0POWER_On << POWER_RAM_POWER_S0POWER_Pos)      |
                            (POWER_RAM_POWER_S1POWER_On      << POWER_RAM_POWER_S1POWER_Pos)      |
                            (POWER_RAM_POWER_S2POWER_On      << POWER_RAM_POWER_S2POWER_Pos)      |
                            (POWER_RAM_POWER_S3POWER_On      << POWER_RAM_POWER_S3POWER_Pos)      |
                            (POWER_RAM_POWER_S4POWER_On      << POWER_RAM_POWER_S4POWER_Pos)      |
                            (POWER_RAM_POWER_S5POWER_On      << POWER_RAM_POWER_S5POWER_Pos)      |
                            (POWER_RAM_POWER_S6POWER_On      << POWER_RAM_POWER_S6POWER_Pos)      |
                            (POWER_RAM_POWER_S7POWER_On      << POWER_RAM_POWER_S7POWER_Pos)      |
                            (POWER_RAM_POWER_S8POWER_On      << POWER_RAM_POWER_S8POWER_Pos)      |
                            (POWER_RAM_POWER_S9POWER_On      << POWER_RAM_POWER_S9POWER_Pos)      |
                            (POWER_RAM_POWER_S10POWER_On     << POWER_RAM_POWER_S10POWER_Pos)     |
                            (POWER_RAM_POWER_S11POWER_On     << POWER_RAM_POWER_S11POWER_Pos)     |
                            (POWER_RAM_POWER_S12POWER_On     << POWER_RAM_POWER_S12POWER_Pos)     |
                            (POWER_RAM_POWER_S13POWER_On     << POWER_RAM_POWER_S13POWER_Pos)     |
                            (POWER_RAM_POWER_S14POWER_On     << POWER_RAM_POWER_S14POWER_Pos)     |
                            (POWER_RAM_POWER_S15POWER_On     << POWER_RAM_POWER_S15POWER_Pos)     |
                            (POWER_RAM_POWER_S0RETENTION_Off  << POWER_RAM_POWER_S0RETENTION_Pos)  |
                            (POWER_RAM_POWER_S1RETENTION_Off  << POWER_RAM_POWER_S1RETENTION_Pos)  |
                            (POWER_RAM_POWER_S2RETENTION_Off  << POWER_RAM_POWER_S2RETENTION_Pos)  |
                            (POWER_RAM_POWER_S3RETENTION_Off  << POWER_RAM_POWER_S3RETENTION_Pos)  |
                            (POWER_RAM_POWER_S4RETENTION_Off  << POWER_RAM_POWER_S4RETENTION_Pos)  |
                            (POWER_RAM_POWER_S5RETENTION_Off  << POWER_RAM_POWER_S5RETENTION_Pos)  |
                            (POWER_RAM_POWER_S6RETENTION_Off  << POWER_RAM_POWER_S6RETENTION_Pos)  |
                            (POWER_RAM_POWER_S7RETENTION_Off  << POWER_RAM_POWER_S7RETENTION_Pos)  |
                            (POWER_RAM_POWER_S8RETENTION_Off  << POWER_RAM_POWER_S8RETENTION_Pos)  |
                            (POWER_RAM_POWER_S9RETENTION_Off  << POWER_RAM_POWER_S9RETENTION_Pos)  |
                            (POWER_RAM_POWER_S10RETENTION_Off << POWER_RAM_POWER_S10RETENTION_Pos) |
                            (POWER_RAM_POWER_S11RETENTION_Off << POWER_RAM_POWER_S11RETENTION_Pos) |
                            (POWER_RAM_POWER_S12RETENTION_Off << POWER_RAM_POWER_S12RETENTION_Pos) |
                            (POWER_RAM_POWER_S13RETENTION_Off << POWER_RAM_POWER_S13RETENTION_Pos) |
                            (POWER_RAM_POWER_S14RETENTION_Off << POWER_RAM_POWER_S14RETENTION_Pos) |
                            (POWER_RAM_POWER_S15RETENTION_Off << POWER_RAM_POWER_S15RETENTION_Pos);
}

Is that correct? 

Best regards,
Alex

[Kenneth]

Hi,

Looks correct, but do check out the description:
https://infocenter.nordicsemi.com/topic/ps_nrf52840/power.html#ram_sections 

Kenneth

[Alex_Huang]

OK, Thanks again!