AnsweredAssumed Answered

[MQX4.1] K20D50M Problem Exiting VLPR mode

Question asked by Hui Shao on Jan 22, 2016
Latest reply on Feb 16, 2016 by Hui Shao

Hi-

 

My board is based on MK20DX128VFM5 and powered my MQX4.1.1.

 

Testing low power mode using VLPR by following demo code from Freescale_MQX_4_1\mqx\examples\lowpower. What I can see is the current consumption is decreased by 20mA on entering VLPR mode. But I can't get it back to RUN mode by using MQX APIs in the demo code. Here are what I used:

 

enter VLPR:

 

 

_lpm_set_clock_configuration(BSP_CLOCK_CONFIGURATION_2MHZ);

_lpm_set_operation_mode (LPM_OPERATION_MODE_WAIT);

 

exit  VLPR:

_lpm_set_operation_mode (LPM_OPERATION_MODE_RUN);

_lpm_set_clock_configuration(BSP_CLOCK_CONFIGURATION_DEFAULT);

 

THe code above crashed in API _lpm_set_clock_configuration(BSP_CLOCK_CONFIGURATION_DEFAULT), what is the reason for it?

 

How can I verify the ARM core is running at 4MHz?

 

Another question is, since my application enters VLPR mode immediately  after power on, the IAR used can't JTAG it to load a new code in because VLPR prevents from FLASH programming. Any solution to it?

 

Thanks!

 

Hui

Outcomes