* $Revision: 5 $ * $Date: 14/06/30 4:51p $ * @brief Demonstrate how to trigger ADC by PWM. * @note * Copyright (C) 2014 Nuvoton Technology Corp. All rights reserved. * ******************************************************************************/#include <stdio.h>#include "NUC131.h"#define PLL_CLOCK 50000000/*---------------------------------------------------------------------------------------------------------*//* Define Function Prototypes *//*---------------------------------------------------------------------------------------------------------*/void SYS_Init(void); //系统初始化void UART0_Init(void); //串口初始化void ADC_PWMTrigTest_SingleOpMode(void); //ADC硬件触发测试void SYS_Init(void) //选择时钟，选择模块，配置引脚 { /*---------------------------------------------------------------------------------------------------------*//* Init System Clock *//*---------------------------------------------------------------------------------------------------------*//* Enable Internal RC 22.1184MHz clock */ CLK_EnableXtalRC(CLK_PWRCON_OSC22M_EN_Msk); //选择内部RC时钟 /* Waiting for Internal RC clock ready */ CLK_WaitClockReady(CLK_CLKSTATUS_OSC22M_STB_Msk); /* Switch HCLK clock source to Internal RC and HCLK source divide 1 */ CLK_SetHCLK(CLK_CLKSEL0_HCLK_S_HIRC, CLK_CLKDIV_HCLK(1));//分频 /* Enable external XTAL 12MHz clock */ CLK_EnableXtalRC(CLK_PWRCON_XTL12M_EN_Msk); /* Waiting for external XTAL clock ready */ CLK_WaitClockReady(CLK_CLKSTATUS_XTL12M_STB_Msk); /* Set core clock as PLL_CLOCK from PLL */ CLK_SetCoreClock(PLL_CLOCK); /* Enable UART module clock */ CLK_EnableModuleClock(UART0_MODULE); /* Enable ADC module clock */ CLK_EnableModuleClock(ADC_MODULE); /* Enable PWM0 module clock */ CLK_EnableModuleClock(PWM0_MODULE); /* Select UART module clock source */ CLK_SetModuleClock(UART0_MODULE, CLK_CLKSEL1_UART_S_HXT, CLK_CLKDIV_UART(1)); /* Select PWM01 module clock source */ CLK_SetModuleClock(PWM0_MODULE, CLK_CLKSEL3_PWM0_S_PCLK, 0); /* ADC clock source is 22.1184MHz, set divider to 7, ADC clock is 22.1184/7 MHz */ CLK_SetModuleClock(ADC_MODULE, CLK_CLKSEL1_ADC_S_HIRC, CLK_CLKDIV_ADC(7)); /*---------------------------------------------------------------------------------------------------------*//* Init I/O Multi-function *//*---------------------------------------------------------------------------------------------------------*//* Set GPB multi-function pins for UART0 RXD and TXD */ SYS->GPB_MFP &= ~(SYS_GPB_MFP_PB0_Msk | SYS_GPB_MFP_PB1_Msk);//配置串口引脚 SYS->GPB_MFP |= SYS_GPB_MFP_PB0_UART0_RXD | SYS_GPB_MFP_PB1_UART0_TXD; /* Disable the GPA0 - GPA3 digital input path to avoid the leakage current. */ GPIO_DISABLE_DIGITAL_PATH(PA, 0xF);//禁用GPA0 - GPA3数字输入路径以避免泄漏电流 /* Configure the GPA0 - GPA3 ADC analog input pins */ SYS->GPA_MFP &= ~(SYS_GPA_MFP_PA0_Msk | SYS_GPA_MFP_PA1_Msk | SYS_GPA_MFP_PA2_Msk | SYS_GPA_MFP_PA3_Msk) ;//配置GPA//0至PA3位为ADC模拟输入引脚 SYS->GPA_MFP |= SYS_GPA_MFP_PA0_ADC0 | SYS_GPA_MFP_PA1_ADC1 | SYS_GPA_MFP_PA2_ADC2 | SYS_GPA_MFP_PA3_ADC3 ;//引脚复用 /* Configure the PA12 as PWM0 output pin */ SYS->GPA_MFP = (SYS->GPA_MFP & (~SYS_GPA_MFP_PA12_Msk));//配置PWM0的引脚 SYS->GPA_MFP |= SYS_GPA_MFP_PA12_PWM0_CH0;//PWM0的0通道}/*---------------------------------------------------------------------------------------------------------*//* Init UART *//*---------------------------------------------------------------------------------------------------------*/void UART0_Init()//复位，和打开串口模块{ /* Reset IP */ SYS_ResetModule(UART0_RST); /* Configure UART0 and set UART0 Baudrate */ UART_Open(UART0, 115200);}/*---------------------------------------------------------------------------------------------------------*//* Function: ADC_PWMTrigTest_SingleOpMode *//**//* Parameters: *//* None. *//**//* Returns: *//* None. *//**//* Description: *//* ADC hardware trigger test. ADC硬件触发测试。 *//*---------------------------------------------------------------------------------------------------------*/void ADC_PWMTrigTest_SingleOpMode()//这个得好好讲讲了 说明PWM是如何激发ADC进行读取的。{ printf("\n<<< PWM trigger test (Single mode) >>>\n"); /* Set the ADC operation mode as single, input mode as single-end and enable the analog input channel 2 */ ADC_Open(ADC, ADC_ADCR_DIFFEN_SINGLE_END, ADC_ADCR_ADMD_SINGLE, 0x1 << 2);//将ADC操作模式设置为单一模式，输入模式为单端，并启用模拟输入通道2 打开ADC通道 /* Power on ADC module */ ADC_POWER_ON(ADC);//#define ADC_POWER_ON(adc) ((adc)->ADCR |= ADC_ADCR_ADEN_Msk)//Before starting A/D conversion function, ADEN bit (ADCR[0]) should be set to 1.在启动A / D转换功能之前，应将ADEN位（ADCR [0]）设置为1。 /* Configure the hardware trigger condition and enable hardware trigger; PWM trigger delay: (4*10) system clock cycles*/ ADC_EnableHWTrigger(ADC, ADC_ADCR_TRGS_PWM, 0);//配置硬件触发条件并启用硬件触发; PWM触发延迟：（4 * 10）个系统时钟周期/****************************************************************************************************************************************************** /* /** * @brief Configure the hardware trigger condition and enable hardware trigger.配置硬件触发条件并启用硬件触发 * @param[in] adc The pointer of the specified ADC module.adc指定ADC模块的指针。 * @param[in] u32Source Decides the hardware trigger source. Valid values are: u32Source决定硬件触发源。 * - \ref ADC_ADCR_TRGS_STADC :A/D conversion is started by external STADC pin.A / D转换由外部STADC引脚启动 * - \ref ADC_ADCR_TRGS_PWM :A/D conversion is started by PWM.//A / D转换由PWM启动 * @param[in] u32Param ADC trigger by external pin, this parameter is used to set trigger condition. Valid values are://u32Param ADC由外部引脚触发，//该参数用于设置触发条件。 * - \ref ADC_ADCR_TRGCOND_LOW_LEVEL :STADC Low level active. * - \ref ADC_ADCR_TRGCOND_HIGH_LEVEL :STADC High level active. * - \ref ADC_ADCR_TRGCOND_FALLING_EDGE :STADC Falling edge active. * - \ref ADC_ADCR_TRGCOND_RISING_EDGE :STADC Rising edge active. * @return None * @details Software should disable TRGEN (ADCR[8]) and ADST (ADCR[11]) before change TRGS(ADCR[5:4]). */void ADC_EnableHWTrigger(ADC_T *adc, uint32_t u32Source, uint32_t u32Param){ ADC->ADCR &= ~(ADC_ADCR_TRGS_Msk | ADC_ADCR_TRGCOND_Msk | ADC_ADCR_TRGEN_Msk); ADC->ADCR |= u32Source | u32Param | ADC_ADCR_TRGEN_Msk; return;}*******************************************************************************************************************************************************/ /* Clear the A/D interrupt flag for safe */ ADC_CLR_INT_FLAG(ADC, ADC_ADF_INT);//清除A / D中断标志以确保安全 /* Center-aligned type 该宏设置PWM对齐类型*/ PWM_SET_ALIGNED_TYPE(PWM0, PWM_CH_0_MASK, PWM_CENTER_ALIGNED);//中心对齐的类型/****************************************************************************************************************************************************** /** * @brief This macro set the PWM aligned type * @param[in] pwm The pointer of the specified PWM module * @param[in] u32ChannelMask Combination of enabled channels. Each bit corresponds to a channel. Every two channels share the same setting. * Bit 0 represents channel 0, bit 1 represents channel 1... * @param[in] u32AlignedType PWM aligned type, valid values are: * - \ref PWM_EDGE_ALIGNED * - \ref PWM_CENTER_ALIGNED * @return None * @details This macro is used to set the PWM aligned type of specified channel(s). * \hideinitializer */#define PWM_SET_ALIGNED_TYPE(pwm, u32ChannelMask, u32AlignedType) \ do{ \ int i; \ for(i = 0; i < 6; i++) { \ if((u32ChannelMask) & (1 << i)) \ (pwm)->CTL1 = (((pwm)->CTL1 & ~(3UL << ((i >> 1) << 2))) | ((u32AlignedType) << ((i >> 1) << 2))); \ } \ }while(0)02*************************************************************************************************************************************************************//* Clock prescaler 时钟预分频器*/ PWM_SET_PRESCALER(PWM0, 0, 1);//该宏设置所选通道的预分频器/******************************************************************************************************************************************************** /** * @brief This macro set the prescaler of the selected channel * @param[in] pwm The pointer of the specified PWM module * @param[in] u32ChannelNum PWM channel number. Valid values are between 0~5 PWM通道 * @param[in] u32Prescaler Clock prescaler of specified channel. Valid values are between 1 ~ 0xFFF u32Prescaler指定通道的时钟预分频器。// 有效值在1?0xFFF之间 * @return None * @details This macro is used to set the prescaler of specified channel. * @note Every even channel N, and channel (N + 1) share a prescaler. So if channel 0 prescaler changed, * channel 1 will also be affected. * \hideinitializer */#define PWM_SET_PRESCALER(pwm, u32ChannelNum, u32Prescaler) (*(__IO uint32_t *) (&((pwm)->CLKPSC0_1) + ((u32ChannelNum) >> 1)) = (u32Prescaler))***********************************************************************************************************************************************************************//* PWM counter value *//* PWM frequency = PWM clock source/(clock prescaler setting + 1)/(CNR+1) */ PWM_SET_CNR(PWM0, 0, 5);//该宏设置所选通道的周期/**********************************************************************************************************************************************************

/**
* @brief This macro set the period of the selected channel
* @param[in] pwm The pointer of the specified PWM module
* @param[in] u32ChannelNum PWM channel number. Valid values are between 0, 2, 4. Every two channels share the same setting.
* @param[in] u32CNR Period of specified channel. Valid values are between 0~0xFFFF
* @return None
* @details This macro is used to set the period of specified channel.
* @note This new setting will take effect on next PWM period.
* @note PWM counter will stop if period length set to 0.
* \hideinitializer
*/
#define PWM_SET_CNR(pwm, u32ChannelNum, u32CNR) ((pwm)->PERIOD[(((u32ChannelNum) >> 1) << 1)] = (u32CNR))

/** * @brief This macro set the comparator of the selected channel * @param[in] pwm The pointer of the specified PWM module * @param[in] u32ChannelNum PWM channel number. Valid values are between 0~5 * @param[in] u32CMR Comparator of specified channel. Valid values are between 0~0xFFFF * @return None * @details This macro is used to set the comparator of specified channel. * @note This new setting will take effect on next PWM period. * \hideinitializer */#define PWM_SET_CMR(pwm, u32ChannelNum, u32CMR) ((pwm)->CMPDAT[(u32ChannelNum)] = (u32CMR))**********************************************************************************************************************************************************/ /* PWM compare value */ PWM_SET_CMR(PWM0, 0, 1);/******************************************************************************************************************************************************* /** * @brief This macro set the comparator of the selected channel 该宏设置所选通道的比较器 * @param[in] pwm The pointer of the specified PWM module * @param[in] u32ChannelNum PWM channel number. Valid values are between 0~5 * @param[in] u32CMR Comparator of specified channel. Valid values are between 0~0xFFFF 指定通道的u32CMR比较器。 有效值在0?0xFFFF之间 * @return None * @details This macro is used to set the comparator of specified channel.该宏用于设置指定通道的比较器。 * @note This new setting will take effect on next PWM period.这个新设置将在下一个PWM周期生效。 * \hideinitializer */#define PWM_SET_CMR(pwm, u32ChannelNum, u32CMR) ((pwm)->CMPDAT[(u32ChannelNum)] = (u32CMR))***************************************************************************************************************************************************************//* Enable PWM0 to trigger ADC */ PWM_EnableADCTrigger(PWM0, 0, PWM_TRIGGER_ADC_EVEN_PERIOD_POINT);//使能PWM来触发ADC/******************************************************************************************************************************************************/** * @brief Enable selected channel to trigger ADC * @param[in] pwm The pointer of the specified PWM module * - PWM0 : PWM Group 0 * - PWM1 : PWM Group 1 * @param[in] u32ChannelNum PWM channel number. Valid values are between 0~5 * @param[in] u32Condition The condition to trigger ADC. Combination of following conditions: * - \ref PWM_TRIGGER_ADC_EVEN_ZERO_POINT * - \ref PWM_TRIGGER_ADC_EVEN_PERIOD_POINT * - \ref PWM_TRIGGER_ADC_EVEN_ZERO_OR_PERIOD_POINT * - \ref PWM_TRIGGER_ADC_EVEN_COMPARE_UP_COUNT_POINT * - \ref PWM_TRIGGER_ADC_EVEN_COMPARE_DOWN_COUNT_POINT * - \ref PWM_TRIGGER_ADC_ODD_COMPARE_UP_COUNT_POINT * - \ref PWM_TRIGGER_ADC_ODD_COMPARE_DOWN_COUNT_POINT#define PWM_TRIGGER_ADC_EVEN_ZERO_POINT (0UL) /*!< PWM trigger ADC while counter of even channel matches zero point */PWM触发ADC，偶数通道计数器匹配零点#define PWM_TRIGGER_ADC_EVEN_PERIOD_POINT (1UL) /*!< PWM trigger ADC while counter of even channel matches period point */当偶数通道计数器匹配周期点时，PWM触发ADC#define PWM_TRIGGER_ADC_EVEN_ZERO_OR_PERIOD_POINT (2UL) /*!< PWM trigger ADC while counter of even channel matches zero or period point */PWM触发ADC，偶数通道计数器匹配零点或周期点#define PWM_TRIGGER_ADC_EVEN_COMPARE_UP_COUNT_POINT (3UL) /*!< PWM trigger ADC while counter of even channel matches up count to comparator point */当偶数通道计数器匹配时PWM触发ADC计数到比较器点#define PWM_TRIGGER_ADC_EVEN_COMPARE_DOWN_COUNT_POINT (4UL) /*!< PWM trigger ADC while counter of even channel matches down count to comparator point */PWM触发ADC，而偶数通道计数器的匹配下降计数到比较点#define PWM_TRIGGER_ADC_ODD_COMPARE_UP_COUNT_POINT (8UL) /*!< PWM trigger ADC while counter of odd channel matches up count to comparator point */PWM触发ADC将奇数通道计数器匹配到比较器点数#define PWM_TRIGGER_ADC_ODD_COMPARE_DOWN_COUNT_POINT (9UL) /*!< PWM trigger ADC while counter of odd channel matches down count to comparator point */PWM触发ADC将奇数通道计数器下降计数到比较点 * @return None * @details This function is used to enable selected channel to trigger ADC. */void PWM_EnableADCTrigger(PWM_T *pwm, uint32_t u32ChannelNum, uint32_t u32Condition){ if(u32ChannelNum < 4) { (pwm)->ADCTS0 &= ~((PWM_ADCTS0_TRGSEL0_Msk) << (u32ChannelNum * 8)); (pwm)->ADCTS0 |= ((PWM_ADCTS0_TRGEN0_Msk | u32Condition) << (u32ChannelNum * 8)); } else { (pwm)->ADCTS1 &= ~((PWM_ADCTS1_TRGSEL4_Msk) << ((u32ChannelNum - 4) * 8)); (pwm)->ADCTS1 |= ((PWM_ADCTS1_TRGEN4_Msk | u32Condition) << ((u32ChannelNum - 4) * 8)); }}*************************************************************************************************************************************************************/ /* PWM0 pin output enabled */ PWM_SET_OUTPUT_LEVEL(PWM0, PWM_CH_0_MASK, PWM_OUTPUT_HIGH, PWM_OUTPUT_NOTHING, PWM_OUTPUT_LOW, PWM_OUTPUT_NOTHING);/*******************************************************************************************************************************************************/** * @brief Set output level at zero, compare up, period(center) and compare down of specified channel(s) 将输出电平设置为零，比较上升，指定通道的周期（中心）和比较下降 * @param[in] pwm The pointer of the specified PWM module // * @param[in] u32ChannelMask Combination of enabled channels. Each bit corresponds to a channel u32ChannelMask已启用通道的组合。 每一位对应一个通道 * Bit 0 represents channel 0, bit 1 represents channel 1... * @param[in] u32ZeroLevel output level at zero point, valid values are:u32ZeroLevel输出电平在零点，有效值是： * - \ref PWM_OUTPUT_NOTHING * - \ref PWM_OUTPUT_LOW * - \ref PWM_OUTPUT_HIGH * - \ref PWM_OUTPUT_TOGGLE * @param[in] u32CmpUpLevel output level at compare up point, valid values are:u32CmpUpLevel比较点的输出电平，有效值为： * - \ref PWM_OUTPUT_NOTHING * - \ref PWM_OUTPUT_LOW * - \ref PWM_OUTPUT_HIGH * - \ref PWM_OUTPUT_TOGGLE * @param[in] u32PeriodLevel output level at period(center) point, valid values are:周期（中心）点的u32PeriodLevel输出电平，有效值为： * - \ref PWM_OUTPUT_NOTHING * - \ref PWM_OUTPUT_LOW * - \ref PWM_OUTPUT_HIGH * - \ref PWM_OUTPUT_TOGGLE * @param[in] u32CmpDownLevel output level at compare down point, valid values are:@param [in] u32CmpDownLevel比较下来的输出级别，有效值是： * - \ref PWM_OUTPUT_NOTHING * - \ref PWM_OUTPUT_LOW * - \ref PWM_OUTPUT_HIGH * - \ref PWM_OUTPUT_TOGGLE * @return None * @details This macro is used to Set output level at zero, compare up, period(center) and compare down of specified channel(s). * \hideinitializer */#define PWM_SET_OUTPUT_LEVEL(pwm, u32ChannelMask, u32ZeroLevel, u32CmpUpLevel, u32PeriodLevel, u32CmpDownLevel) \ do{ \ int i; \ for(i = 0; i < 6; i++) { \ if((u32ChannelMask) & (1 << i)) { \ (pwm)->WGCTL0 = (((pwm)->WGCTL0 & ~(3UL << (2 * i))) | ((u32ZeroLevel) << (2 * i))); \ (pwm)->WGCTL0 = (((pwm)->WGCTL0 & ~(3UL << (PWM_WGCTL0_PRDPCTLn_Pos + (2 * i)))) | \((u32PeriodLevel) << (PWM_WGCTL0_PRDPCTLn_Pos + (2 * i)))); \ (pwm)->WGCTL1 = (((pwm)->WGCTL1 & ~(3UL << (2 * i))) | ((u32CmpUpLevel) << (2 * i))); \ (pwm)->WGCTL1 = (((pwm)->WGCTL1 & ~(3UL << (PWM_WGCTL1_CMPDCTLn_Pos + (2 * i)))) | \((u32CmpDownLevel) << (PWM_WGCTL1_CMPDCTLn_Pos + (2 * i)))); \ } \ } \ }while(0)**********************************************************************************************************************************************************************************************************/ PWM_EnableOutput(PWM0, PWM_CH_0_MASK);/***************************************************************************************************************************************************** /* Start PWM module */ PWM_Start(PWM0, PWM_CH_0_MASK); /* wait for one cycle */while(PWM_GetPeriodIntFlag(PWM0, 0) == 0); while(PWM_GetZeroIntFlag(PWM0, 0) == 0); PWM_ClearPeriodIntFlag(PWM0, 0); PWM_ClearZeroIntFlag(PWM0, 0);/********************************************************************************************************************************************************/** * @brief Get period interrupt of selected channel 获取选定通道的周期中断 * @param[in] pwm The pointer of the specified PWM module * - PWM0 : PWM Group 0 * - PWM1 : PWM Group 1 * @param[in] u32ChannelNum PWM channel number. Valid values are between 0~5. Every two channels share the same setting. * @return Period interrupt flag of specified channel * @retval 0 Period interrupt did not occur * @retval 1 Period interrupt occurred * @details This function is used to get period interrupt of selected channel. */uint32_t PWM_GetPeriodIntFlag(PWM_T *pwm, uint32_t u32ChannelNum){ return (((pwm)->INTSTS0 & (PWM_INTSTS0_PIF0_Msk << ((u32ChannelNum >> 1) << 1))) ? 1 : 0);}/** * @brief Get zero interrupt of selected channel 获取所选通道的零中断 * @param[in] pwm The pointer of the specified PWM module * - PWM0 : PWM Group 0 * - PWM1 : PWM Group 1 * @param[in] u32ChannelNum PWM channel number. Valid values are between 0~5. Every two channels share the same setting. * @return zero interrupt flag of specified channel * @retval 0 zero interrupt did not occur * @retval 1 zero interrupt occurred * @details This function is used to get zero interrupt of selected channel. */uint32_t PWM_GetZeroIntFlag(PWM_T *pwm, uint32_t u32ChannelNum){ return (((pwm)->INTSTS0 & (PWM_INTSTS0_ZIF0_Msk << ((u32ChannelNum >> 1) << 1))) ? 1 : 0);}/** * @brief Stop PWM generation immediately by clear channel enable bit * @param[in] pwm The pointer of the specified PWM module * - PWM0 : PWM Group 0 * - PWM1 : PWM Group 1 * @param[in] u32ChannelMask Combination of enabled channels. Each bit corresponds to a channel. * Bit 0 is channel 0, bit 1 is channel 1... * @return None * @details This function is used to stop PWM generation immediately by clear channel enable bit. 该功能用于通过清除通道使能位立即停止PWM的产生。 */void PWM_ForceStop(PWM_T *pwm, uint32_t u32ChannelMask){ uint32_t i; for(i = 0; i < PWM_CHANNEL_NUM; i ++) { if(u32ChannelMask & (1 << i)) { (pwm)->CNTEN &= ~(1UL << ((i >> 1) << 1)); } }}/** * @brief Return the user-specified interrupt flags. 返回用户指定的中断标志。 * @param[in] adc The pointer of the specified ADC module. * @param[in] u32Mask The combination of following interrupt status bits. Each bit corresponds to a interrupt status.//u32Mask以下中断状态位的组合。 每个位对应一个中断状态 * Valid values are: * - \ref ADC_ADF_INT :Convert complete interrupt flag. * - \ref ADC_CMP0_INT :Comparator 0 interrupt flag. * - \ref ADC_CMP1_INT :Comparator 1 interrupt flag. * @return User specified interrupt flags. * @details Get the status of the ADC interrupt flag. */#define ADC_GET_INT_FLAG(adc, u32Mask) ((adc)->ADSR & (u32Mask))**************************************************************************************************************************************************************/ /* Stop PWM generation */ PWM_ForceStop(PWM0, PWM_CH_0_MASK); /* Wait conversion done */while(!ADC_GET_INT_FLAG(ADC, ADC_ADF_INT)); /* Clear the ADC interrupt flag */ ADC_CLR_INT_FLAG(ADC, ADC_ADF_INT); printf("Channel 2: 0x%X\n", ADC_GET_CONVERSION_DATA(ADC, 2));//ADC获取转换数据 /* Disable ADC */ ADC_POWER_DOWN(ADC);/*********************************************************************************************************************************************************///**   *提示关闭ADC模块。   * @param [in] adc指定ADC模块的指针。   * @返回无   * @details禁用A / D转换器模拟电路以节省功耗。   * @note无  */#define ADC_POWER_DOWN（adc）（（adc） - > ADCR＆=?ADC_ADCR_ADEN_Msk）***********************************************************************************************************************************************************//*---------------------------------------------------------------------------------------------------------*//* MAIN function *//*---------------------------------------------------------------------------------------------------------*/ int32_t main(void) { /* Unlock protected registers */ SYS_UnlockReg(); /* Init System, IP clock and multi-function I/O */ SYS_Init(); /* Lock protected registers */ SYS_LockReg(); /* Init UART0 for printf */ UART0_Init(); /*---------------------------------------------------------------------------------------------------------*//* SAMPLE CODE *//*---------------------------------------------------------------------------------------------------------*/ printf("\nSystem clock rate: %d Hz", SystemCoreClock); /* ADC hardware trigger test */ ADC_PWMTrigTest_SingleOpMode(); /* Disable ADC module */ ADC_Close(ADC); /* Disable ADC IP clock */ CLK_DisableModuleClock(ADC_MODULE); /* Disable External Interrupt */ NVIC_DisableIRQ(ADC_IRQn); printf("\nExit ADC sample code\n"); while(1); }

这里插几则知识点：

1. 边沿对齐模式

   当PWM 时基工作在自由运行模式时，模块产生边沿对齐的PWM 信号。给定PWM 通道的输出
信号的周期由装入PTPER 的值指定， 其占空比由相应的PDCx 寄存器指定（参见图15-7 ）。
设占空比非零且立即更新未被使能（ IUE = 0），所有使能的PWM 发生器的输出在PWM 周期开
始（ PTMR = 0）时被驱动为有效。当PTMR 的值与PWM 发生器的占空比值发生匹配时，各
PWM 输出都被驱动为无效。
如果PDCx 寄存器中的值为0，则相应的PWM 引脚的输出在整个PWM 周期内都将为无效。此
外，如果PDCx 寄存器中的值大于PTPER 寄存器中保存的值， 那么PWM 引脚的输出在整个
PWM 周期内都将有效。
如果使能了立即更新（ IUE = 1），则在新值写入任一有效的PDC 寄存器时，新的占空比值即被
装入。

    当PWM时基配置为两个向上/向下计数模式（PTMOD<1:0> = 1x）之一时，模块将产生中心对齐的PWM信号。

void ADC_PWMTrigTest_SingleOpMode(){ printf("\n<<< PWM trigger test (Single mode) >>>\n"); /* Set the ADC operation mode as single, input mode as single-end and enable the analog input channel 2 */ ADC_Open(ADC, ADC_ADCR_DIFFEN_SINGLE_END, ADC_ADCR_ADMD_SINGLE, 0x1 << 2);//操作模式选为单段输入模式，输入模式位单一模式 /* Power on ADC module */ ADC_POWER_ON(ADC); /* Configure the hardware trigger condition and enable hardware trigger; PWM trigger delay: (4*10) system clock cycles*/ ADC_EnableHWTrigger(ADC, ADC_ADCR_TRGS_PWM, 0);//硬件触发条件 /* Clear the A/D interrupt flag for safe */ ADC_CLR_INT_FLAG(ADC, ADC_ADF_INT); /* Center-aligned type */ PWM_SET_ALIGNED_TYPE(PWM0, PWM_CH_4_MASK, PWM_CENTER_ALIGNED); /* Clock prescaler */ PWM_SET_PRESCALER(PWM0, 0, 1); /* PWM counter value *//* PWM frequency = PWM clock source/(clock prescaler setting + 1)/(CNR+1) */ PWM_SET_CNR(PWM0, 0, 5); /* PWM compare value */ PWM_SET_CMR(PWM0, 0, 1); /* Enable PWM0 to trigger ADC */ PWM_EnableADCTrigger(PWM0, 0, PWM_TRIGGER_ADC_EVEN_PERIOD_POINT); /* PWM0 pin output enabled */ PWM_SET_OUTPUT_LEVEL(PWM0, PWM_CH_0_MASK, PWM_OUTPUT_HIGH, PWM_OUTPUT_NOTHING, PWM_OUTPUT_LOW, PWM_OUTPUT_NOTHING); PWM_EnableOutput(PWM0, PWM_CH_0_MASK); /* Start PWM module */ PWM_Start(PWM0, PWM_CH_0_MASK); /* wait for one cycle */while(PWM_GetPeriodIntFlag(PWM0, 0) == 0); while(PWM_GetZeroIntFlag(PWM0, 0) == 0); PWM_ClearPeriodIntFlag(PWM0, 0); PWM_ClearZeroIntFlag(PWM0, 0); /* Stop PWM generation */ PWM_ForceStop(PWM0, PWM_CH_0_MASK); /* Wait conversion done */while(!ADC_GET_INT_FLAG(ADC, ADC_ADF_INT)); /* Clear the ADC interrupt flag */ ADC_CLR_INT_FLAG(ADC, ADC_ADF_INT); printf("Channel 2: 0x%X\n", ADC_GET_CONVERSION_DATA(ADC, 2)); /* Disable ADC */ ADC_POWER_DOWN(ADC); while(1);}