SW-DK-TM4C123G: GPIOPinTypeGPIOInput triggers FaultISR

user1651456

Part Number: SW-DK-TM4C123G

Hi:

I am writing a very simple piece of code to enable the GPIO on pin 4 of Port M. The code is below. To make sure, I created a new program that ONLY has the code below. The issue I am having is that the GPIOPinTypeGPIOInput function causes the FaultISR to be triggered and the program hangs in there

GPIOIntRegister(GPIO_PORTM_BASE, PortMIntHandler);
GPIOPinTypeGPIOInput(GPIO_PORTM_BASE, 0x10);
GPIODirModeSet(GPIO_PORTM_BASE, GPIO_PIN_4, GPIO_DIR_MODE_IN);
GPIOPadConfigSet(GPIO_PORTM_BASE, GPIO_PIN_4, GPIO_STRENGTH_2MA, GPIO_PIN_TYPE_STD_WPU);

Any ideas as to what am I missing here?

Thanks

Asad

over 6 years ago

0 Ralph Jacobi over 6 years ago

TI__Guru*** 128265 points

Hello Asad,

Do you have the PortMIntHandler properly defined in the startup_ccs.c file?

You will need to add it as an extern function to the file and then change the IntDefaultHandler for GPIO Port M to be the PortMIntHandler function. You can look at the TivaWare interrupts example for reference if needed.

0 Bob Crosby over 6 years ago

TI__Guru 72500 points

You must enable GPIO_PORTM before configuring the pin type.

    //
    // Enable the GPIO port
    //
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOM);

    //
    // Check if the peripheral access is enabled.
    //
    while(!SysCtlPeripheralReady(SYSCTL_PERIPH_GPIOM))
    {
    }

    GPIOPinTypeGPIOInput(GPIO_PORTM_BASE, GPIO_PIN_4);

0 Ralph Jacobi over 6 years ago in reply to Bob Crosby

TI__Guru*** 128265 points

Hi Bob,

Thanks for pointing out the enable calls, I didn't notice the comment of 'ONLY the code below' originally. Definitely need that as well.

0 user1651456 over 6 years ago in reply to Bob Crosby

Prodigy 20 points

Thanks!! I cannot believe I missed that
Asad

0 cb1_mobile over 6 years ago in reply to user1651456

Guru 117850 points

user1651456 said:
I cannot believe I missed that

Feel neither "bad or alone!" Most all (possibly ALL) of the "code examples" provided w/in the "Peripheral Driver Library's User Guide" AVOID such required initialization.

Arm-based microcontrollers

Arm-based microcontrollers forum

SW-DK-TM4C123G: GPIOPinTypeGPIOInput triggers FaultISR