topic Configure VLPS mode in MKL16Z and use UART0 in Kinetis Microcontrollers

Configure VLPS mode in MKL16Z and use UART0

karthikbandi — Fri, 21 Jul 2017 14:04:25 GMT

Hello,

I want to configure the MKL16Z64 to low power VLPS mode. But in the low power configuration PE doesnot support to configure VLPS mode, i can see only LLS and VLLSx.

But how can i configure it, I want to use UART0 to wakeup the MCU from lowpower mode. Which low power mode do i need to use and how i can configure it. Please provide me some info.

Thanks

Re: Configure VLPS mode in MKL16Z and use UART0

Robin_Shen — Wed, 09 Aug 2017 07:54:20 GMT

Hi KARTHIK,

Sorry for the late reply!

Very low power modes (e.g. VLPS) can be used on Kinetis derivatives but you must allow these very low power modes in the CPU component (these modes have CPU clock frequencies restrictions). The detailed instructions (how to set the CPU and very low power modes) are described in the document Operation modes in Processor Expert.

Best Regards,

Robin

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Re: Configure VLPS mode in MKL16Z and use UART0

Robin_Shen — Mon, 14 Aug 2017 09:19:58 GMT

Hi KARTHIK,

I am not sure if you have configure the MKL16Z64 to low power VLPS mode.

If you have read the Operation modes in Processor Expert, you will find the VLPS in below table:

Prior to enter VLPS mode you need to enter a VLPR mode, this is what is indicated in the mentioned document. To accomplish this you need to set a Clock Configuration for BLPE or BLPI mode checking the Very low power mode as enabled, here an example: (I also attached the project here so you can test it.)

You enter the Clock configuration calling the methods Cpu_SetClockConfiguration(); and Cpu_GetClockConfiguration();. After ensuring you are running the BLPI or BLPE configuration you call the Cpu_SetOperationMode(DOM_SLEEP, NULL, NULL) to enter VLPS mode. This is the normal behavior of the MCU you can check more information in the AN4503 document. Referring to it:

"STOP mode entry routine:

if in Run mode puts the processor into normal stop mode.

If in VLPR mode puts the processor into VLPS mode.

In this mode core, bus and peripheral clocks are disabled."

As you mentioned before it is possible to enter VLPS mode from Normal RUN mode but this is not implemented in Processor Expert.

Best Regards,

Robin