topic How to use UART to wake from sleep mode in Kinetis Microcontrollers

How to use UART to wake from sleep mode

vanajagujjala — Wed, 10 Feb 2016 14:40:52 GMT

Hi,

1. How to use UART interrupt to wake up uC from sleep mode in K20.

2. Is it possible with UART Interrupt?

3. How much current consumption in sleep mode?

Please help

Thanks

vanaja.

Re: How to use UART to wake from sleep mode

mjbcswitzerland — Wed, 10 Feb 2016 16:10:45 GMT

https://community.freescale.com/message/421247#421247

Regards

Mark

Re: How to use UART to wake from sleep mode

vanajagujjala — Thu, 11 Feb 2016 04:22:35 GMT

Hi Mark,

Thanks for your reply. let me go through this and get back to you.

Vanaja.

Re: How to use UART to wake from sleep mode

vanajagujjala — Sat, 20 Feb 2016 13:30:42 GMT

Hi Mark,

Sorry for the delay,I migrated to some other work.

1. I tried STOP mode,while running the code current is 10.5mA after enter into run mode current down to 4.6mA,but in Reference Manual and some where else i read in stop mode current is 0.4mA ?

2. I tried K20 low power demo,In this example they are using LLWU is using to wake MCU from stop mode,but in my case i need to wake MCU if any character/data received from UART interrupt mode (9600 baud rate),in stop mode all clock are disabled?

3. From the Reference Manual MCU wake up from STOP mode by using AWIC, Is it ture?

Please help me & is there any wrong understanding by me.

Re: How to use UART to wake from sleep mode

mjbcswitzerland — Sat, 20 Feb 2016 17:49:05 GMT

- The user's manual decribes the various low power modes; you need a low leakage mode to get to very low current consumption. Some such modes allow specific clocks to remain enabled or be disabled so this depends to some extent on the code using it.

- Various asynchronous events can wake the processor from a LLWU mode (this is controlled by the AWIC).

- The UART edge interrupt is an asynchronous event which is designed to allow waking the processor on UART reception.

Regards

Mark