ISR Problem Solving Flowchart?

Discussion in 'Embedded Systems and Microcontrollers' started by Bonker, Oct 18, 2010.

  1. Bonker

    Thread Starter New Member

    Jul 9, 2009
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    0
    I've had so many hiccups trying to work out when ISR's are not working or executing. Does a flowchart exist that might help me save some time debugging issues with ISR's?
     
  2. wannaBinventor

    Member

    Apr 8, 2010
    179
    4
    What type of problems are you having? Why don't you post the code and let us see if we can help?

    I think some of the datasheets for the PIC show a logic flowchart for the different bits that need to be set for different interrupts to be enabled.

    I'd advise you to make sure your enabling global interrupts AS WELL AS your peripheral interrupts if you are trying to use those. That seems to be a fairly common mistake I think.
     
  3. atferrari

    AAC Fanatic!

    Jan 6, 2004
    2,645
    759
    Never seen a flowchart but the register/s involved with an explanation bit by bit.

    If you run thoroughly through them you can manage to set interrupts properly.

    Added: if you manage to understand the logic diagram explaining how the interrupts are handled you could even find another way to know why any particular interrupt is not working.

    Make sure to set/reset all bits involved.

    Be patient and optimist.
     
  4. Bonker

    Thread Starter New Member

    Jul 9, 2009
    2
    0
    This is a school thing - not homework just general ongoing issues slowing me down - so I don't want help with the code so much as maybe some methods or steps to track down issues. Right now, if the interrupt is enabled and has the correct priority, I don't know what else to check in the case where it doesn't execute. FWIW, I'm using an HCS12 on a Dragonboard and Codewarrior for my IDE.
     
  5. wannaBinventor

    Member

    Apr 8, 2010
    179
    4
    Perhaps I was mistaken on there being a logic diagram. I could have sworn I saw one somewhere.

    Why don't you draw out a logic diagram for the different interrupt enable bits and flag bits for whatever PIC you normally work with and I'm sure some one here could look at it and tell you if you have it correct or not.

    I think that would prove to be a good future reference and learning experience.
     
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