Fatal SD error writing to NRF_POWER->RAM[0].POWERSET

[supernovah]

As the title specifies, on writing to the registers mentioned, I receive a Fatal error.

Here's the test code

void save_ram()
{
	__DSB();
	NRF_POWER->RAM[0].POWERSET = 0xFFFFFFFF; // All RAM[0]
	__DSB();
	__NOP();
}

Engineering errata mentions reading having to be done on .POWER rather than .POWERSET but nothing about no write capability.

Is there something obviously wrong with this? It seems debugging it which inserts a lot of time delay, might allow it to work.

[Vidar Berg]

Hi, the POWER module is protected while the softdevice is enabled (Peripheral runtime protection), but can be accessed through the softdevice API (sd_power_ram_power_set)

[supernovah]

Ah thanks. Is there some documentation I should be reading?

[Vidar Berg]

Yes, recommend to have a look at the following two links from the Softdevice specification:

• Hardware peripherals
• Memory isolation and runtime protection

[supernovah]

Is it appropriate to assume the s132 documentation applies to s140 when anoteher article doesn't supersede it?

[Vidar Berg]

s140 specification is not ready yet, but will be when the first production release is out. You can use the s132 specification until then.