如何用28377的ecap功能实现连续采样PWM波的频率

感谢您的回复，我再参考了下例程，这两个都是单次捕获模式的，同时设置上我也参考了下，应该是没问题。

GPIO口的设置不是这个函数吗

//Setup up the GPIO input/output options for the specified pin.
//The flags are a 16-bit mask produced by ORing together options.
//For input pins, the valid flags are:
//GPIO_PULLUP    Enable pull-up
//GPIO_INVERT    Enable input polarity inversion
//GPIO_SYNC        Synchronize the input latch to PLLSYSCLK (default -- you don't need to specify this)
//GPIO_QUAL3    Use 3-sample qualification
//GPIO_QUAL6    Use 6-sample qualification
//GPIO_ASYNC    Do not use synchronization or qualification
//(Note: only one of SYNC, QUAL3, QUAL6, or ASYNC is allowed)
//
//For output pins, the valid flags are:
//GPIO_OPENDRAIN    Output in open drain mode
//GPIO_PULLUP        If open drain enabled, also enable the pull-up
//and the input qualification flags (SYNC/QUAL3/QUAL6/SYNC) listed above.
//
//With no flags, the default input state is synchronous with no
//pull-up or polarity inversion. The default output state is
//the standard digital output.
void GPIO_SetupPinOptions(Uint16 pin, Uint16 output, Uint16 flags)
{
    volatile Uint32 *gpioBaseAddr;
    volatile Uint32 *dir, *pud, *inv, *odr, *qsel;
    Uint32 pin32, pin16, pinMask, qual;

    pin32 = pin % 32;
    pin16 = pin % 16;
    pinMask = 1UL << pin32;
    gpioBaseAddr = (Uint32 *)&GpioCtrlRegs + (pin/32)*GPY_CTRL_OFFSET;

    //Create pointers to the appropriate registers. This is a workaround
    //for the way GPIO registers are defined. The standard definition
    //in the header file makes it very easy to do named accesses of one
    //register or bit, but hard to do arbitrary numerical accesses. It's
    //easier to have an array of GPIO modules with identical registers,
    //including arrays for multi-register groups like GPyQSEL1-2. But
    //the header file doesn't define anything we can turn into an array,
    //so manual pointer arithmetic is used instead.
    dir = gpioBaseAddr + GPYDIR;
    pud = gpioBaseAddr + GPYPUD;
    inv = gpioBaseAddr + GPYINV;
    odr = gpioBaseAddr + GPYODR;
    qsel = gpioBaseAddr + GPYQSEL + pin32/16;

    EALLOW;

    //Set the data direction
    *dir &= ~pinMask;
    if (output == 1)
    {
        //Output, with optional open drain mode and pull-up
        *dir |= pinMask;

        //Enable open drain if necessary
        if (flags & GPIO_OPENDRAIN)
            *odr |= pinMask;
        else
            *odr &= ~pinMask;

        //Enable pull-up if necessary. Open drain mode must be active.
        if (flags & (GPIO_OPENDRAIN | GPIO_PULLUP))
            *pud &= ~pinMask;
        else
            *pud |= pinMask;
    } else
    {
        //Input, with optional pull-up, qualification, and polarity inversion
        *dir &= ~pinMask;

        //Enable pull-up if necessary
        if (flags & GPIO_PULLUP)
            *pud &= ~pinMask;
        else
            *pud |= pinMask;

        //Invert polarity if necessary
        if (flags & GPIO_INVERT)
            *inv |= pinMask;
        else
            *inv &= ~pinMask;
    }

    //Extract the qualification parameter and load it into the register. This is
    //also needed for open drain outputs, so we might as well do it all the time.
    qual = (flags & GPIO_ASYNC) / GPIO_QUAL3;
    *qsel &= ~(0x3L << (2 * pin16));
    if (qual != 0x0)
        *qsel |= qual << (2 * pin16);

    EDIS;
}