TM4C1294NCPDT: Input Edge-Time mode does not work as expected

Hi, Charles

    Thanks for your reply, I use the DRM because it looks more strait forward to me, also, I remember using TivaWare functions in the interrupt handler causes warnings

    I would peruse your code and check what I am missing in my code

Thanks

Steven

Hi, Charles

    I still have several questions to your reference code:

    1: In the function of TimerConfigure, I found below code which always sets the bit of TnPWMIE bit for TAMR or TBMR, since the purpose is to set Input Edge-Time mode, why should TnPWMIE bit set in the TnMR register?

    if(NEW_TIMER_CONFIGURATION)
    {
        HWREG(ui32Base + TIMER_O_TAMR) = (((ui32Config & 0x000f0000) >> 4) |
                                          (ui32Config & 0xff) |
                                          TIMER_TAMR_TAPWMIE);
        HWREG(ui32Base + TIMER_O_TBMR) = (((ui32Config & 0x00f00000) >> 8) |
                                          ((ui32Config >> 8) & 0xff) |
                                          TIMER_TBMR_TBPWMIE);
    }
    else
    {
        HWREG(ui32Base + TIMER_O_TAMR) = ((ui32Config & 0xff) |
                                          TIMER_TAMR_TAPWMIE);
        HWREG(ui32Base + TIMER_O_TBMR) = (((ui32Config >> 8) & 0xff) |
                                          TIMER_TBMR_TBPWMIE);
    }

    2: In the function     GPIOPinTypeTimer(), I found below code:

    //
    // Set the pad(s) for standard push-pull operation.
    //
    GPIOPadConfigSet(ui32Port, ui8Pins, GPIO_STRENGTH_2MA, GPIO_PIN_TYPE_STD);

    Does this indicate the pin can only be set to standard push pull mode if it is configured as TxCCPx pin?

Hi, Charles

    I need to configure Timer1_A to Input Edge Time Mode and detect the time on the positive edge on pin PD2, with the reference code you provided above, I composed the code as below for Timer1_A, but I still can not have the Timer1_A interrupt triggered, please can you further help to check if there would be something wrong with the code below:

    SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER1);
    TimerConfigure(TIMER1_BASE, (TIMER_CFG_SPLIT_PAIR | TIMER_CFG_A_CAP_TIME_UP));
    TimerControlEvent(TIMER1_BASE, TIMER_A, TIMER_EVENT_POS_EDGE);

    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);
    GPIOPinConfigure(GPIO_PD2_T1CCP0);
    GPIOPinTypeTimer(GPIO_PORTD_BASE, GPIO_PIN_2);

    // Registers a interrupt function to be called when timer b hits a neg edge event
    IntRegister(INT_TIMER1A, Timer1IntHandler);
    // Makes sure the interrupt is cleared
    TimerIntClear(TIMER1_BASE, TIMER_CAPA_EVENT);
    // Enable the indicated timer interrupt source.
    TimerIntEnable(TIMER1_BASE, TIMER_CAPA_EVENT);
    // The specified interrupt is enabled in the interrupt controller.
    IntEnable(INT_TIMER1A);

Hi Steven,

  I didn't see you enable the NVIC interrupt at the processor level. Please call IntMasterEnable() to enable the processor interrupt. Let me know if this will solve your problem. 

Hi, Charles

    I add IntMasterEnable function after the Timer1 initializing finished, but the interrupt still could not be triggered.

    I also checked lsb in PRIMASK register, the bit is always cleared before and after IntMasterEnable function is called, this indicates the NVIC interrupt is already enabled in previous code. Could there be any other reason for the Timer Interrupt failed to be triggered

Hi Steve,

  There is a edge-time CCS project example in TivaWare library. You can find the example in C:\ti\TivaWare_C_Series-2.2.0.295\examples\boards\ek-tm4c1294xl\timer_edge_capture. Can you please try this example as is and see if you can get it to work. Once working, you can modify for Timer1. I think what you are missing is the below two lines. Anyway, try the example first and see if you can get it to work.