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LLS state and LLWU module

Question asked by Renata Levinsky on Feb 1, 2012
Latest reply on Sep 10, 2012 by Philip Drake



I'm working with K60 on Tower board.I have a question about LLWU module and enter-exit from LLS mode. 

My simple project  example code has

  • Start system like in Freescale example projects
  • Start the lpt timer and lpt interrupt.
  • In loop:
    • Some artificial delay function
    • Enter to LLS mode 

The LLWU ISR function is also defined in vector isr table. From datasheet the LLWU isr must not be masked.

The result is

  • The program enters to LLS mode
  • LLWU wakeup isr is occurred
  • LPT isr is occurred right after LLWU Isr
  • But after LPT Isr,the LLWU Isr is occurred again,so LLWU Isr is encapsulate LPT Isr.(I right a simple log to see this scenario).Could you help me to understand, why LLWU Isr is “pending” again after LPT Isr?


The second question is what need to be in the body of LLWU Isr function? Now I didn’t do nothing in the context of LLWU Isr,and after LPT ISR I make the following:

“  NVICICPR0|=(1<<21); //Clear LLWU interrupt

   NVICISER0|=(1<<21); //Enable LLWU interrupt

The additional LLWU Isr didn’t occurred, but the J-link disconnected from CPU.

Any help will be welcomed!!!Thanks.