CC3220SF-LAUNCHXL: Retention registers

Sai Kishore Valaboju

Hi,

I am using tcpecho example and writing something to INDEX0 of the retention registers, upon wakeup the registers seems to be modified all the time.

I see from the driverlib prcm.c BIT01 to BIT14 can be used by user application even if RTC is in use.

Can someone please explain why the values are getting modified and what can I do about it?

prcm.c

//! When RTC APIs in use:
//! |-----------------------------------------------|
//! | INDEX 0 |
//! |-----------------------------------------------|
//! |31|30|29|28|27|26|25|24|23|22|21|20|19|18|17|16|
//! |-----------------------------------------------|
//! | Reserved by RTC APIs - YY |
//! |-----------------------------------------------|
//! |15|14|13|12|11|10|09|08|07|06|05|04|03|02|01|00|
//! |-----------------------------------------------|
//! |YY| For User Application |XX|
//! |-----------------------------------------------|
//!
//! YY => Reserved by RTC APIs. If Driverlib RTC APIs are used
//! XX => Reserved by ROM

over 6 years ago

0 Vincent Rodriguez over 6 years ago

TI__Mastermind 28285 points

Sai,

What are you using as your wakeup source? Are you intializing the RTC?

Best Regards,
Vince

0 Sai Kishore Valaboju over 6 years ago in reply to Vincent Rodriguez

Intellectual 590 points

Hi Vince,

I am using both GPIO and PRCMHibernateIntervalSet(WAKE_INTERVAL) as my wakeup sources, and I am not initializing RTC.

Thank you,
Kishore.

0 Vincent Rodriguez over 6 years ago in reply to Sai Kishore Valaboju

TI__Mastermind 28285 points

Sai,

Can you provide your code where your saving/recalling the info in the hib register?

Best Regards,
Vince

0 Sai Kishore Valaboju over 6 years ago in reply to Vincent Rodriguez

Intellectual 590 points

Hi Vince,

I am suing below code to send the MCU to hibernate mode, for testing I used hardcoded the values.

PRCMHibernateWakeUpGPIOSelect(PRCM_HIB_GPIO13, PRCM_HIB_RISE_EDGE);
PRCMHibernateWakeupSourceEnable(PRCM_HIB_GPIO13| PRCM_HIB_SLOW_CLK_CTR);

PRCMHibernateIntervalSet(32768 * 5);

//PRCMOCRRegisterWrite(0, hibernate_reg );
PRCMOCRRegisterWrite(0, 0x000000FE);
PRCMHibernateEnter();

and below I am using to read while wakeup

int main(void)
{
PRCMHibernateWakeupSourceDisable(0x007F0001);
hibernate_reg=PRCMOCRRegisterRead(0);

Thank you,
Kishore.

0 Vincent Rodriguez over 6 years ago in reply to Sai Kishore Valaboju

TI__Mastermind 28285 points

Kishnore,

You are using the RTC when configuring the interval set function. If the RTC is on, the two hib rentention registers are no longer available for you to save data in. This is because the RTC uses it to save the counter value.

Remove this line, and ensure you aren't calling RTC init() and you should be good.

Best Regards,
Vince

0 Sai Kishore Valaboju over 6 years ago in reply to Vincent Rodriguez

Intellectual 590 points

Hi Vince,

Thank you for the immidiate response, In the original question I put some part of prcm.c, the BITS[31:15] of INDEX0 are used by RTC and BITS[14:01] are for user application.
I thought BITS[31:15] are used by RTC to save counter value and BITS[14:01] are free for user application to retain information.

Is there any way that I can retain the register values and wake the process from hibernation after a certain configured time.

Thank you,
Kishore.

0 Sai Kishore Valaboju over 6 years ago in reply to Sai Kishore Valaboju

Intellectual 590 points

Hi,

Any update on this?

Thank you,
Kishore.

0 Vincent Rodriguez over 6 years ago in reply to Sai Kishore Valaboju

TI__Mastermind 28285 points

Kishnore,

You are not able to use either register when the RTC is on.

Vince

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CC3220SF-LAUNCHXL: Retention registers