本帖最后由 GrootBrain 于 2021-1-29 09:31 编辑
某些场合下，需要用单一一个PWM通道，捕获输入口的上跳变时刻或下跳变时刻。
从7801的参考手册来看，PWM单通道是可以实现双边沿捕获的。
根据参考手册做相应配置，代码如下：
/**
* Capture_init
*
* @param[in] void
* [url=home.php?mod=space&uid=266161]@return[/url] void
*
* [url=home.php?mod=space&uid=247401]@brief[/url] 捕获初始化
*
*/
void Capture_init(void)
{
GPIO_SetFunc(GPIOB, GPIO_PIN3, GPIO_FUN1);
CKGEN_Enable(CLK_PWM0, ENABLE);
CKGEN_SoftReset(SRST_PWM0, ENABLE);
/* Set period value */
PWM_SetClockPrescaler(PWM0, 23);
PWM_SetCounterInitValue((PWM0), 0);
PWM_SetCounter((PWM0), 0);
PWM_SetMaxCountValue((PWM0), 65535);
PWM_SetCountMode(PWM0, PWM_UP_COUNT);
PWM_SetClockSource(PWM0, PWM_CLK_SOURCE_APB);
PWM_SetCallback(PWM0, CaptureIntCallback);
NVIC_EnableIRQ(PWM0_IRQn);
PWM_SetChannelMSR(PWM0, PWM_CH_6, 0U);
PWM_SetChannelELSR(PWM0, PWM_CH_6, PWM_BOTH_EDGE_DETECT);
PWM_SetCaptureEventPrescaler(PWM0, PWM_CH_6, PWM_EVENT_PSC_1);
PWM_SetChannelInterrupt(PWM0, PWM_CH_6, DISABLE);
}
/*!
* [url=home.php?mod=space&uid=247401]@brief[/url] capture start
*
* @param[in]
* modemIndex - modem index (0, 1)
* channelIndex - channel index
* [url=home.php?mod=space&uid=266161]@return[/url]
* 0 - fail
* 1 - success
*
*/
uint8_t CapTime_StartCapture(PWM_Type* ptrCaptureModem, uint8_t channelIndex)
{
memset(g_capture_buf, 0, sizeof(g_capture_buf));
g_capEdgeCounter = 0;
PWM_SetChannelInterrupt(ptrCaptureModem, (PWM_ChannelType)channelIndex, ENABLE);
PWM_SetChannelELSR(ptrCaptureModem, (PWM_ChannelType)channelIndex, 0x03);
return 1;
}
/*!
* @brief capture stop
*
* @param[in]
* modemIndex - modem index (0, 1)
* channelIndex - channel index
* @return
* 0 - fail
* 1 - success
*
*/
uint8_t CapTime_StopCapture(PWM_Type* ptrCaptureModem, uint8_t channelIndex)
{
PWM_SetChannelELSR(ptrCaptureModem, (PWM_ChannelType)channelIndex, 0x00);
PWM_SetChannelInterrupt(ptrCaptureModem, (PWM_ChannelType)channelIndex, DISABLE);
return 1;
}
pwm_capture.rar
(27.36 KB)
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