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Ed Maynard
Ed Maynard
Associate II
September 14, 2017
Question

Is there a way to get CubeMX to link interrupts to a GPIO pin but have the interrupt start DISABLED in the areas of the code it manages?

  • September 14, 2017
  • 1 reply
  • 609 views
Posted on September 14, 2017 at 18:02

Using CubeMX 4.21.0

I have  GPIO that is attached to an EXTI interrupt. (Pin Configuration page)

On the NVIC Configuration page, the EXTI interrupts are Enabled

The EXTI interrupts are checked to generate IRQ handler (Code Generation)

With this configuration, I get the handler and the GPIO_Init() routines enables the interrupt

If I do not check the Enabled box on the NVIC configuration page, I don't get the interrupt handler emitted when the code is generated.

Using the init sequencing moves the interrupt enables to their own file but it is still within the sections of code overwritten by CubeMx. Thus, I would need to keep making changes every time i emit code from CubeMx.

Is there a way to have cubemx generate the interrupt handler and have the interrupt start disabled that does not require post processing the code?

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    1 reply

    Vangelis Fortounas
    Vangelis Fortounas
    Associate II
    September 15, 2017
    Posted on September 15, 2017 at 02:53

    Hello Ed!

    To generate an EXTernal Interrupt, should coexist three factors at the same time.

    1. NVIC EXTI interrupt enabled. It's done by CubeMX automaticaly as you mention above.

    2. Relevant bit set in EXTI_IMR register. It's done by CubeMX automaticaly inside GPIO's init code.

    3. External trigger to the relevant pin. Rising edge or/and falling edge.

     There is not formal way for cubemx generate the interrupt handler and have the interrupt start disabled. If for example, you don't call the MX_GPIO_Init() inside main function, the next initialized devices that use GPIO pins, will affected. 

    A different approach is to clear the relevant with GPIOpin, interrupt mask bit  in EXTI_IMR reg after initialization, by call

    'CLEAR_BIT(GPIOA->IMR, GPIO_PIN_4); '    inside your main function.

    In case EXTI interrupt triggered before clear this bit, you can have allready set a global 'EXTI_Uninitialized' flag before  call MX_GPIO_Init(). This will used inside EXTI callback function ( ISR), to not do anything if this flag is set.

    Just before re-enable interrupt by call 'SET_BIT(GPIOA->IMR, GPIO_PIN_4)'  , reset the 'EXTI_Uninitialized' flag.

    Regards

    vf

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