LPTMR0 Clocked from ERCLK32K in LLS mode of MK60

[rajkumar_yerraj]

Hi,

I am configuring MK60 controller in LLS mode with wake up interrupt from LPTMR0.

SMC_PMCTRL |= SMC_PMCTRL_LPWUI_MASK;

LPTMR0 is sourced from RTC_Oscillator (source to ERCLK32K). 

SIM_SOPT1 |= (SIM_SOPT1_OSC32KSEL_MASK); /* RTC oscillator drives 32 kHz clock for various peripherals */

 LPTMR0 is working fine in Normal Run mode but when it enters the LLS mode, LPTMR0 stopped. But according to 

Power Management for Kinetis MCUs document, LPTimer should work.

Could you tell me, if i am missing anything in configuration .

Thank you.

-Rajkumar

[rajkumar_yerraj]

Hi,

Thanks for the info.

My issue is solved.

-Rajkumar

[nxf54945 · Accepted solution]

Hello Gangadhar rao,

I hope you are doing well. 

When configuring your MCU to go into LLS mode, you need to select which signals will wakeup the system from the Low Leakage Stop (See section 3.3.4.1 “Wake-up Sources” on the reference manual).

This configuration is set on the Low Leakage Wakeup Unit (chapter 16 of the reference manual).  

I found this document which might help you set your application: http://cache.freescale.com/files/32bit/doc/app_note/AN4503.pdf  

Also, in the SDK for the TWR-K60D, in the demo apps folder, you will find the power_manager example. There, you can select the configuration to wake up the MCU using the LPTMR. You can download the SDK here: https://mcuxpresso.nxp.com/en/welcome  

I hope this information helps.  

Best regards, 

Javier