KL14 wake up from VLLS3

[ulivinico]

I'm developing an application with KL14. I was able to enter VLLS3 mode and exit from it by using a button connected to a LLWU input, starting from examples given in code zipped in KL25_SC.exe

Now I need to exit the VLLS3 mode by using a CMP input, when an external input voltage goes below a certain level: is there any given example code to start from?

[kerryzhou · Accepted solution]

Currently, there are no given example code to exit the VLLS3 mode by using a CMP input. But it is not difficult to find that in low_power_demo example there is a cmp.c , you can refer to case 3 in  low_power_ demo example (it use the LPTMR as the wake up source)to write the code.

When you use the cmp.c, some point you need to pay attention in your main.c:

1,set the CMP as the wake up source

llwu_configure(0x0000, LLWU_PIN_FALLING, 0x2);

2, open cmp clock

SIM_SCGC4 |= (SIM_SCGC4_CMP_MASK );

3,enable CMP interrupt

NVIC_EnableIRQ(CMP0_IRQn);

4,initial CMP

cmp_init (0x18);

you can refer the low_power_ demo example to write your own code.

I wish it helps you!

Best regards!

[ulivinico]

Thank you. It works fine. Now I'm trying to understand how to recognize which source causes the wakeup. In my case the internal module#2 - CMP0 or the external pin LLWU5.

After reset, reading the register RCM_SRS0 doesn't help since both CMP and llwu causes to set the same bit WAKEUP.

Which bit and wich register allows to distinguish between the two reset sources?

[ulivinico]

I solved by configuring filtered llwu pin and by using register LLWU_FILT1 to monitor the wakeup source.

[jeremyzhou]

Hi Ulivinico,

I don't think it have any example codes about use CMP to wake up the VLLS3 which is provided by Freescale. Attached is Kinetis L Peripheral Module Quick Reference which include LLWU configuration examples and hope it will help to design.

Regards,

Ping