<p> 各位安：</p><p> 使用AM335X芯片做ecap捕获，用到了全部三个ecap通道，ecap0用于时钟频率捕获，其中ecap1通道和ecap2通道用来捕获45HZ~55HZ方波，ecap1配置为APWM模式时，ecap2可以正常捕获到正确的周期，反之 ecap2设置为APWM模式时，ecap1也可以正常捕获到正确的周期。同时配置为ECAP_CAPTURE_MODE就都不能正常工作，求赐教。</p> <br><p> 代码如下：</p><pre style="max-width: 100%;"><code class="cpp hljs" codemark="1"><span class="hljs-function"><span class="hljs-keyword">int</span> <span class="hljs-title">freq_init</span><span class="hljs-params">(<span class="hljs-keyword">void</span>)</span> </span>{ <span class="hljs-keyword">void</span> __iomem *p_REGS; <span class="hljs-comment">/**************************配置时钟和设备地址映射****************************/</span> p_REGS = ioremap(SOC_PWMSS1_REGS, SZ_8K); <span class="hljs-keyword">if</span>(!p_REGS) { printk(<span class="hljs-string">"%s:ioremap(%x) error "</span>, __func__, SOC_PWMSS1_REGS); <span class="hljs-keyword">return</span> <span class="hljs-number">-1</span>; } g_SOC_PWMSS1_REGS = (<span class="hljs-keyword">unsigned</span> <span class="hljs-keyword">int</span>)p_REGS; g_SOC_ECAP_1_REGS = g_SOC_PWMSS1_REGS + SOC_ECAP_REGS; g_aREGS[<span class="hljs-number">0</span>] = g_SOC_ECAP_1_REGS; p_REGS = ioremap(SOC_PWMSS2_REGS, SZ_8K); <span class="hljs-keyword">if</span>(!p_REGS) { printk(<span class="hljs-string">"%s:ioremap(%x) error "</span>, __func__, SOC_PWMSS2_REGS); iounmap((<span class="hljs-keyword">void</span> __iomem *)g_SOC_CONTROL_REGS); iounmap((<span class="hljs-keyword">void</span> __iomem *)g_SOC_PWMSS1_REGS); <span class="hljs-keyword">return</span> <span class="hljs-number">-1</span>; } g_SOC_PWMSS2_REGS = (<span class="hljs-keyword">unsigned</span> <span class="hljs-keyword">int</span>)p_REGS; g_SOC_ECAP_2_REGS = g_SOC_PWMSS2_REGS + SOC_ECAP_REGS; g_aREGS[<span class="hljs-number">1</span>] = g_SOC_ECAP_2_REGS; <span class="hljs-comment">/* Enable Clock */</span> ECAPClockEnable(g_SOC_PWMSS1_REGS); <span class="hljs-keyword">while</span>(ECAPClockEnableStatusGet(g_SOC_PWMSS1_REGS) == <span class="hljs-number">0</span>); ECAPClockEnable(g_SOC_PWMSS2_REGS); <span class="hljs-keyword">while</span>(ECAPClockEnableStatusGet(g_SOC_PWMSS2_REGS) == <span class="hljs-number">0</span>); <span class="hljs-comment">/***************************配置两个ecap的硬件管脚*****************************/</span> p_REGS = ioremap(SOC_CONTROL_REGS, SZ_8K); <span class="hljs-keyword">if</span>(!p_REGS) { printk(<span class="hljs-string">"%s:ioremap(%x) error "</span>, __func__, SOC_CONTROL_REGS); <span class="hljs-keyword">return</span> <span class="hljs-number">-1</span>; } g_SOC_CONTROL_REGS = (<span class="hljs-keyword">unsigned</span> <span class="hljs-keyword">int</span>)p_REGS; <span class="hljs-comment">/* eCAP1输入管脚 AM335X_ECAP1_IN I2C0_SCL C16 */</span> HWREG(g_SOC_CONTROL_REGS + CONTROL_CONF_I2C0_SCL) = (CONTROL_CONF_PULLUPSEL |CONTROL_CONF_RXACTIVE | CONTROL_CONF_MUXMODE(<span class="hljs-number">3</span>)); <span class="hljs-comment">/* eCAP2输入管脚 eCAP2_in_PWM2_out模式 MCASP0_AHCLKR C12 */</span> HWREG(g_SOC_CONTROL_REGS + CONTROL_CONF_MCASP0_AHCLKR) = (CONTROL_CONF_PULLUPSEL |CONTROL_CONF_RXACTIVE | CONTROL_CONF_MUXMODE(<span class="hljs-number">4</span>)); <span class="hljs-comment">/****************************配置两个ecap的寄存器******************************/</span> <span class="hljs-comment">/* 捕捉模式 ** ECCTL2[9] CAP_APWM CAP/APWM operating mode select ** 0h = ECAP module operates in capture mode. This mode forces the ** following configuration. (a) Inhibits TSCTR resets via PRDEQ event. ** (b) Inhibits shadow loads on CAP1 and 2 registers. (c) Permits user ** to enable CAP1-4 register load. (d) ECAPn/APWMn pin operates as ** a capture input. ** 1h = ECAP module operates in APWM mode. This mode forces the ** following configuration. (a) Resets TSCTR on PRDEQ event (period ** boundary). (b) Permits shadow loading on CAP1 and 2 registers. (c) ** Disables loading of time-stamps into CAP1-4 registers. (d) ** ECAPn/APWMn pin operates as a APWM output. */</span> ECAPOperatingModeSelect(g_SOC_ECAP_1_REGS, ECAP_CAPTURE_MODE); ECAPOperatingModeSelect(g_SOC_ECAP_2_REGS, ECAP_APWM_MODE); <span class="hljs-comment">/* 问题就在此处 ecap2设备APWM模式时 ecap1才能正常捕获，反之亦然 */</span> <span class="hljs-comment">/* 连续模式 ** ECCTL2[0] CONT_ONESHT 0h = Operate in continuous mode */</span> ECAPContinousModeConfig(g_SOC_ECAP_1_REGS); ECAPContinousModeConfig(g_SOC_ECAP_2_REGS); <span class="hljs-comment">/* 清除中断 ** ECCLR[0:7] EC**&amp;0xFF Writing a 1 clears the Int flag condition */</span> ECAPIntStatusClear(g_SOC_ECAP_1_REGS, <span class="hljs-number">0xFF</span>); ECAPIntStatusClear(g_SOC_ECAP_2_REGS, <span class="hljs-number">0xFF</span>); <span class="hljs-comment">/* 这里的分频是指输入信号的分频，不是ECAP的时钟分频 ** ECCTL1[9:13] PRESCALE 0h = Divide by 1 (i.e,. no prescale, by-pass the prescaler) */</span> ECAPPrescaleConfig(g_SOC_ECAP_1_REGS, <span class="hljs-number">0</span>); ECAPPrescaleConfig(g_SOC_ECAP_2_REGS, <span class="hljs-number">0</span>); <span class="hljs-comment">/* enables capture loading ** ECCTL1[8] CAPLDEN 1h = Enable CAP1-4 register loads at capture event time. */</span> ECAPCaptureLoadingEnable(g_SOC_ECAP_1_REGS); ECAPCaptureLoadingEnable(g_SOC_ECAP_2_REGS); <span class="hljs-comment">/* configures Capture Event polarity.上升沿捕捉 */</span> ECAPCapeEvtPolarityConfig(g_SOC_ECAP_1_REGS, EC_RISING_EDGE, EC_RISING_EDGE, EC_RISING_EDGE, EC_RISING_EDGE); ECAPCapeEvtPolarityConfig(g_SOC_ECAP_2_REGS, EC_RISING_EDGE, EC_RISING_EDGE, EC_RISING_EDGE, EC_RISING_EDGE); <span class="hljs-comment">/* enables reset of the counters upon Capture Events. */</span> ECAPCaptureEvtCntrRstConfig(g_SOC_ECAP_1_REGS, EC_DELTA_MODE, EC_DELTA_MODE, EC_DELTA_MODE, EC_DELTA_MODE); ECAPCaptureEvtCntrRstConfig(g_SOC_ECAP_2_REGS, EC_DELTA_MODE, EC_DELTA_MODE, EC_DELTA_MODE, EC_DELTA_MODE); <span class="hljs-comment">/* 0h = Stop after Capture Event 1 in one-shot mode. Wrap after Capture Event 1 in continuous mode 0-&gt;0-&gt;0 CAP1 */</span> <span class="hljs-comment">//ECAPStopWrapConfig(g_SOC_ECAP_1_REGS, ECAP_CAPTURE_EVENT4_STOP);</span> <span class="hljs-comment">//ECAPStopWrapConfig(g_SOC_ECAP_2_REGS, ECAP_CAPTURE_EVENT1_STOP);</span> <span class="hljs-comment">/* 使能中断 */</span> ECAPIntEnable(g_SOC_ECAP_1_REGS, ECAP_CEVT1_INT|ECAP_CEVT2_INT|ECAP_CEVT3_INT|ECAP_CEVT4_INT); ECAPIntEnable(g_SOC_ECAP_2_REGS, ECAP_CEVT1_INT|ECAP_CEVT2_INT|ECAP_CEVT3_INT|ECAP_CEVT4_INT); <span class="hljs-comment">/* Disables the sync out ,sync in. TI定义的宏ECAP_SYNC_OUT_DISABLE有问题，改用EC_SYNC_OUT_DISABLE ** ECCTL2[5] SYNCI_EN 0h = Disable sync-in option ** ECCTL2[6:7] SYNCO_SEL 2h = Disable sync out signal */</span> ECAPSyncInOutSelect(g_SOC_ECAP_1_REGS, ECAP_SYNC_IN_DISABLE, EC_SYNC_OUT_DISABLE); ECAPSyncInOutSelect(g_SOC_ECAP_2_REGS, ECAP_SYNC_IN_DISABLE, EC_SYNC_OUT_DISABLE); <span class="hljs-comment">/* Set Counter ** RSCTR[0:31] 0 Active 32 bit counter register that is used as the capture time-base */</span> ECAPCounterConfig(g_SOC_ECAP_1_REGS, <span class="hljs-number">0</span>); ECAPCounterConfig(g_SOC_ECAP_2_REGS, <span class="hljs-number">0</span>); <span class="hljs-comment">/* 自由运行 ECCTL2[4] 1 TSCTRSTOP-&gt;TSCTR free-running 计数器停止位控制 计数器开始计数 */</span> ECAPCounterControl(g_SOC_ECAP_1_REGS, ECAP_COUNTER_FREE_RUNNING); ECAPCounterControl(g_SOC_ECAP_2_REGS, ECAP_COUNTER_FREE_RUNNING); rt_request_irq(CFG_ECAP1INT, CFG_INT_LEVEL_ECAP, freq_isr0, <span class="hljs-string">"ecap1"</span>, <span class="hljs-number">0</span>); rt_request_irq(CFG_ECAP2INT, CFG_INT_LEVEL_ECAP, freq_isr1, <span class="hljs-string">"ecap2"</span>, <span class="hljs-number">0</span>); <span class="hljs-keyword">return</span> <span class="hljs-number">0</span>; } <span class="hljs-function"><span class="hljs-keyword">void</span> <span class="hljs-title">freq_isr</span><span class="hljs-params">(<span class="hljs-keyword">int</span> index)</span> </span>{ <span class="hljs-keyword">unsigned</span> <span class="hljs-keyword">int</span> status, count = <span class="hljs-number">0</span>; <span class="hljs-keyword">float</span> freq; <span class="hljs-comment">/* 读取中断状态值 */</span> status = ECAPIntStatus(g_aREGS[index], <span class="hljs-number">0x3F</span>); <span class="hljs-keyword">if</span>(status &amp; ECAP_CEVT1_INT) { count = ECAPTimeStampRead(g_aREGS[index], ECAP_CAPTURE_EVENT_1); } <span class="hljs-keyword">if</span>(status &amp; ECAP_CEVT2_INT) { count = ECAPTimeStampRead(g_aREGS[index], ECAP_CAPTURE_EVENT_2); } <span class="hljs-keyword">if</span>(status &amp; ECAP_CEVT3_INT) { count = ECAPTimeStampRead(g_aREGS[index], ECAP_CAPTURE_EVENT_3); } <span class="hljs-keyword">if</span>(status &amp; ECAP_CEVT4_INT) { count = ECAPTimeStampRead(g_aREGS[index], ECAP_CAPTURE_EVENT_4); } <span class="hljs-comment">/* 清中断标志位 */</span> ECAPIntStatusClear(g_aREGS[index], <span class="hljs-number">0x3F</span>); <span class="hljs-comment">/* 换算成频率.不能除0 */</span> <span class="hljs-keyword">if</span>(count) { freq = (<span class="hljs-keyword">float</span>)ECAP_CLK_FREQ/count; } <span class="hljs-keyword">else</span> { freq = <span class="hljs-number">0</span>; } <span class="hljs-comment">//将频率范围限定在45hz到55hz。</span> <span class="hljs-keyword">if</span>(freq&gt;=<span class="hljs-number">44.0</span> &amp;&amp; freq &lt;= <span class="hljs-number">56.0</span>) { g_freqency[index] = freq; } } </code></pre><p><br></p>