• 状态
  • 已锁定 已锁定
  • 个回复 2 个回复
  • 名订阅用户 25 名订阅用户
  • 次查看 1536 次查看
  • 用户 0 名在线用户
选项
选项
相关

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

28379D Ecap中断触发延时 捕获外部脉冲上升沿 延时太长

user4669408
Intellectual 300 points

DSP28379D在调用DSP内部Ecap 脉冲捕获功能时，如下图所示CH4绿色通道是我DSP外部的GPIO口给到Ecap模块进行捕获的方波，CH3是DSP捕获到CH4脉冲上升沿触发Ecap中断程序后实现GPIO口的翻转来测试Ecap的延时时间，为什么会有260ns的延时时间啊？

目前系统时钟配置为200MHz, datasheet上关于GPIO的延时采5个系统时钟周期以内，260ns太长了不正常啊，我现在要用到1MHz以上的开关频率，这个延时太大了无法接受啊


 

  • 0
    TI__Guru**** 252096 points
    “CH3是DSP捕获到CH4脉冲上升沿触发Ecap中断程序后实现GPIO口的翻转来测试Ecap的延时时间”

    中断的触发，中断程序的执行以及GPIO反转都是需要时间的。

    请问能否给出详细代码？
  • 0 回复 Susan Yang
    Intellectual 300 points

    void Ecap_Init(void)
    {

    EALLOW;
    InputXbarRegs.INPUT7SELECT = 21; // Set eCAP1 source to GPIO-pin
    EDIS;

    GPIO_SetupPinOptions(21, GPIO_INPUT, GPIO_ASYNC);

    ECap1Regs.ECEINT.all = 0x0000; // Disable all capture __interrupts
    ECap1Regs.ECCLR.all = 0xFFFF; // Clear all CAP __interrupt flags
    ECap1Regs.ECCTL1.bit.CAPLDEN = 0; // Disable CAP1-CAP4 register loads
    ECap1Regs.ECCTL2.bit.TSCTRSTOP = 0; // Make sure the counter is stopped

    // Configure peripheral registers
    ECap1Regs.ECCTL2.bit.CONT_ONESHT = 1; // One-shot
    ECap1Regs.ECCTL2.bit.STOP_WRAP = 0;//3; // Stop at 4 events
    ECap1Regs.ECCTL1.bit.CAP1POL = 0; // Falling edge
    ECap1Regs.ECCTL1.bit.CAP2POL = 0; // Rising edge
    ECap1Regs.ECCTL1.bit.CAP3POL = 0; // Falling edge
    ECap1Regs.ECCTL1.bit.CAP4POL = 0; // Rising edge
    ECap1Regs.ECCTL1.bit.CTRRST1 = 1; // Difference operation
    ECap1Regs.ECCTL1.bit.CTRRST2 = 1; // Difference operation
    ECap1Regs.ECCTL1.bit.CTRRST3 = 1; // Difference operation
    ECap1Regs.ECCTL1.bit.CTRRST4 = 1; // Difference operation
    ECap1Regs.ECCTL2.bit.SYNCI_EN = 0; // Enable sync in
    ECap1Regs.ECCTL2.bit.SYNCO_SEL = 0; // Pass through
    ECap1Regs.ECCTL1.bit.CAPLDEN = 1; // Enable capture units

    ECap1Regs.ECCTL2.bit.TSCTRSTOP = 1; // Start Counter
    ECap1Regs.ECCTL2.bit.REARM = 1; // arm one-shot
    ECap1Regs.ECCTL1.bit.CAPLDEN = 1; // Enable CAP1-CAP4 register loads
    ECap1Regs.ECEINT.bit.CEVT1 = 1; // 1 events = __interrupt
    // ECap1Regs.ECEINT.bit.CEVT4 = 1; // 4 events = __interrupt

    }/* Ecap_Init() */


    interrupt void ecap1_isr(void)
    {

    EALLOW;
    GpioDataRegs.GPASET.bit.GPIO12 = 1;
    EDIS;
    ECap1Regs.ECCLR.bit.CEVT1 = 1;

    ECap1Regs.ECCLR.bit.INT = 1;
    ECap1Regs.ECCTL2.bit.REARM = 1;

    // Acknowledge this __interrupt to receive more __interrupts from group 4
    PieCtrlRegs.PIEACK.all = PIEACK_GROUP4;

    GpioDataRegs.GPACLEAR.bit.GPIO12 = 1;

    }