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标题: 28035的eCAP功能 [打印本页]

作者: reporter 时间: 2013-9-5 14:15 标题: 28035的eCAP功能

使用eCAP来检测方波的频率，开始的时候让单片机自己的EPWM产生50Hz的方波，检测到是50，但是当接到外在方波电路的时候就不对了，为什么呢？设置如下。。。

&nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;ECap1Regs.ECEINT.all = 0x0000;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; // Disable all capture interrupts禁止所有的捕获中断
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; ECap1Regs.ECCLR.all = 0xFFFF;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;// Clear all CAP interrupt flags清除所有的捕获标志位
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; ECap1Regs.ECCTL1.bit.CAPLDEN = 0;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; // Disable CAP1-CAP4 register loads禁止加载CAP1-CAP4寄存器
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; ECap1Regs.ECCTL2.bit.TSCTRSTOP = 0;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;// Make sure the counter is stopped确保计数器停止计数
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; ECap1Regs.TSCTR = 0;

&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; // Configure peripheral registers
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; ECap1Regs.ECCTL2.bit.CONT_ONESHT = 0;&nbsp; &nbsp;&nbsp; &nbsp;// 连续触发模式
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; ECap1Regs.ECCTL1.bit.CAP1POL = 0;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; // 上升沿
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; ECap1Regs.ECCTL1.bit.CAP2POL = 0;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; // 上升沿
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; ECap1Regs.ECCTL1.bit.CAP3POL = 0;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; // 上升沿
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; ECap1Regs.ECCTL1.bit.CAP4POL = 0;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; // 上升沿
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; ECap1Regs.ECCTL1.bit.CTRRST1 = 0;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; // 不使能重新计数
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; ECap1Regs.ECCTL1.bit.CTRRST2 = 0;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; // 不使能重新计数
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; ECap1Regs.ECCTL1.bit.CTRRST3 = 0;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; // 不使能重新计数
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; ECap1Regs.ECCTL1.bit.CTRRST4 = 0;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; // 不使能重新计数
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; ECap1Regs.ECCTL2.bit.SYNCI_EN = 0;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;// 禁止
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; ECap1Regs.ECCTL2.bit.SYNCO_SEL = 2;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;// 旁路时钟

&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; ECap1Regs.ECCTL1.bit.CAPLDEN = 1;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; // 使能捕获单元加载
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; ECap1Regs.ECCTL1.bit.PRESCALE = 0;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;// 不分频
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; ECap1Regs.ECCTL2.bit.CAP_APWM = 0;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;// 运行在CAP模式下
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; ECap1Regs.ECCTL2.bit.TSCTRSTOP = 0;

&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; ECap1Regs.ECCTL2.bit.TSCTRSTOP = 1;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;// 开启计数器
&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; ECap1Regs.ECCTL1.bit.CAPLDEN = 1;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; // Enable CAP1-CAP4 register loads
&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;ECap1Regs.ECEINT.bit.CEVT4 = 1;

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