[nRF51422] Using of GPREGRET

RE: [nRF51422] Using of GPREGRET

PW — Mon, 22 Jul 2013 17:01:59 GMT

I knew about flashwrite solution, but I tried to avoid it. However in this situation, it will be best way.

Best regards PW

RE: [nRF51422] Using of GPREGRET

Håkon Alseth — Fri, 19 Jul 2013 12:45:23 GMT

Hi,

I've misread your application.

If you want to store variables after reset, you must store the variable to flash. There's an example on this in our SDK, which is called "flashwrite_example".

GPREGRET register will be cleared after reset. Same with RAM.

Best regards Håkon

RE: [nRF51422] Using of GPREGRET

PW — Fri, 19 Jul 2013 11:42:20 GMT

I don't use poweroff. What about RAM content when random reset occurs? Can I read unchanged variable when I use power_ramon function earlier (etc. at the beginning of the program) .

Best regards PW

RE: [nRF51422] Using of GPREGRET

Håkon Alseth — Fri, 19 Jul 2013 10:46:31 GMT

Hi,

Due to the RESETREAS register is PAN'ed in the current revision of the device, you must workaround this by powering on the RAM (since GPREGRET is unavailable in S210).

Use the sd_power_ramon_set API call:

/**@brief Sets bits in the NRF_POWER->RAMON register.
 *
 * @param[in] ramon Contains the bits needed to be set in the NRF_POWER->RAMON register.
 *
 * @return ::NRF_SUCCESS
 */
uint32_t SVCALL(SD_POWER_RAMON_SET) sd_power_ramon_set(uint32_t ramon);

This call is directly mapped 1:1 on how you would set the RAMON register. If you set one variable declared within the area of RAM block 1, you can use this for checking wakeup source: static uint8_t reset_reason_from_systemoff attribute((at(0x20001000)));

Set this before going into systemoff, and do a check when waking up again.

Best regards Håkon

RE: [nRF51422] Using of GPREGRET

PW — Fri, 19 Jul 2013 10:06:33 GMT

I must remember program status in case reset occurs. Can I do it in RAM?

BR PW

RE: [nRF51422] Using of GPREGRET

Håkon Alseth — Fri, 19 Jul 2013 09:56:13 GMT

Hi,

Using the S210 stack, this is unfortunately not possible. There is no API call to get/set this register.

What are you trying to use this register for? If you power on the RAM while going into sleep, you can retain your variables when awoken.

BR Håkon