平台：Code Composer Studio 10.3.1
MSP430F5529 LaunchPad™ Development Kit
(MSP‑EXP430F5529LP)

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1.通过Timer_A_outputPWM配置产生PWM波

所选输出引脚为P1.2

初始化函数

#define TIMER_PERIOD 12500
void Timer_A_PWM_Init(void)
{Timer_A_outputPWMParam htim = {0};//P1.2复用输出GPIO_setAsPeripheralModuleFunctionOutputPin(GPIO_PORT_P1, GPIO_PIN2);	//时钟源选为SMCLK = 25MHzhtim.clockSource = TIMER_A_CLOCKSOURCE_SMCLK;	//分频系数设为40htim.clockSourceDivider = TIMER_A_CLOCKSOURCE_DIVIDER_40;//装载值设为12500 - 1htim.timerPeriod = TIMER_PERIOD - 1;//P1.2 对应 TA0.1 故设为TIMER_A_CAPTURECOMPARE_REGISTER_1htim.compareRegister = TIMER_A_CAPTURECOMPARE_REGISTER_1;htim.compareOutputMode = TIMER_A_OUTPUTMODE_RESET_SET;//初始比较值为装载值的一半 即初始占空比为50%htim.dutyCycle = TIMER_PERIOD / 2;//P1.2 对应 TA0.1 为TIMER_A0_BASETimer_A_outputPWM(TIMER_A0_BASE, &htim);
}

计算

时钟源为SMCLK = 25MHz
分频系数为40
装载值为12500 - 1
故所得PWM频率为25MHz/40/12500=50Hz

修改占空比的函数

修改占空比即修改比较值，故使用Timer_A_setCompareValue函数

我选择在外部中断服务函数内进行修改，按下一次按钮分别为占空比减少10%和增加10%

//******************************************************************************
//
//This is the PORT2_VECTOR interrupt vector service routine
//
//******************************************************************************
#pragma vector=PORT2_VECTOR     // P2口中断源
__interrupt
void Port_2 (void)              // 声明一个中断服务程序，名为Port_2()
{if(GPIO_getInterruptStatus(GPIO_PORT_P2, GPIO_PIN1)){delay_ms(20);if(!GPIO_getInputPinValue(GPIO_PORT_P2, GPIO_PIN1)){//P1.0 = toggleTimer_A_setCompareValue(TIMER_A0_BASE,TIMER_A_CAPTURECOMPARE_REGISTER_1,Timer_A_getCaptureCompareCount(TIMER_A0_BASE, TIMER_A_CAPTURECOMPARE_REGISTER_1) - TIMER_PERIOD / 10);while(!GPIO_getInputPinValue(GPIO_PORT_P2, GPIO_PIN1));}//P2.1 IFG clearedGPIO_clearInterrupt(GPIO_PORT_P2, GPIO_PIN1);}
}//******************************************************************************
//
//This is the PORT1_VECTOR interrupt vector service routine
//
//******************************************************************************
#pragma vector=PORT1_VECTOR     // P2口中断源
__interrupt
void Port_1 (void)              // 声明一个中断服务程序，名为Port_1()
{if(GPIO_getInterruptStatus(GPIO_PORT_P1, GPIO_PIN1)){delay_ms(20);if(!GPIO_getInputPinValue(GPIO_PORT_P1, GPIO_PIN1)){//P1.0 = toggleTimer_A_setCompareValue(TIMER_A0_BASE,TIMER_A_CAPTURECOMPARE_REGISTER_1,Timer_A_getCaptureCompareCount(TIMER_A0_BASE, TIMER_A_CAPTURECOMPARE_REGISTER_1) + TIMER_PERIOD / 10);while(!GPIO_getInputPinValue(GPIO_PORT_P1, GPIO_PIN1));}//P2.1 IFG clearedGPIO_clearInterrupt(GPIO_PORT_P1, GPIO_PIN1);}
}

整体程序

#include "driverlib.h"#define MCLK_IN_HZ      25000000#define delay_us(x)     __delay_cycles((MCLK_IN_HZ/1000000*(x)))
#define delay_ms(x)     __delay_cycles((MCLK_IN_HZ/1000*(x)))void SystemClock_Init(void)
{PMM_setVCore(PMM_CORE_LEVEL_3);     //高主频工作需要较高的核心电压//XT1引脚复用GPIO_setAsPeripheralModuleFunctionInputPin(GPIO_PORT_P5, GPIO_PIN4);GPIO_setAsPeripheralModuleFunctionOutputPin(GPIO_PORT_P5, GPIO_PIN5);//起振XT1UCS_turnOnLFXT1(UCS_XT1_DRIVE_3,UCS_XCAP_3);//XT2引脚复用GPIO_setAsPeripheralModuleFunctionInputPin(GPIO_PORT_P5, GPIO_PIN2);GPIO_setAsPeripheralModuleFunctionOutputPin(GPIO_PORT_P5, GPIO_PIN3);//起振XT2UCS_turnOnXT2(UCS_XT2_DRIVE_4MHZ_8MHZ);//XT2作为FLL参考时钟，先8分频，再50倍频 4MHz / 8 * 50 = 25MHzUCS_initClockSignal(UCS_FLLREF, UCS_XT2CLK_SELECT, UCS_CLOCK_DIVIDER_8);UCS_initFLLSettle(25000, 50);//XT1作为ACLK时钟源 = 32768HzUCS_initClockSignal(UCS_ACLK, UCS_XT1CLK_SELECT, UCS_CLOCK_DIVIDER_1);//DCOCLK作为MCLK时钟源 = 25MHzUCS_initClockSignal(UCS_MCLK, UCS_DCOCLK_SELECT, UCS_CLOCK_DIVIDER_1);//DCOCLK作为SMCLK时钟源 = 25MHzUCS_initClockSignal(UCS_SMCLK, UCS_DCOCLK_SELECT, UCS_CLOCK_DIVIDER_1);//设置外部时钟源的频率，使得在调用UCS_getMCLK, UCS_getSMCLK 或 UCS_getACLK时可得到正确值UCS_setExternalClockSource(32768, 4000000);
}#define TIMER_PERIOD 12500
void Timer_A_PWM_Init(void)
{Timer_A_outputPWMParam htim = {0};GPIO_setAsPeripheralModuleFunctionOutputPin(GPIO_PORT_P1, GPIO_PIN2);htim.clockSource = TIMER_A_CLOCKSOURCE_SMCLK;htim.clockSourceDivider = TIMER_A_CLOCKSOURCE_DIVIDER_40;htim.timerPeriod = TIMER_PERIOD - 1;htim.compareRegister = TIMER_A_CAPTURECOMPARE_REGISTER_1;htim.compareOutputMode = TIMER_A_OUTPUTMODE_RESET_SET;htim.dutyCycle = TIMER_PERIOD / 2;Timer_A_outputPWM(TIMER_A0_BASE, &htim);
}void KEY_S1_Init(void)
{GPIO_setAsInputPinWithPullUpResistor(GPIO_PORT_P2, GPIO_PIN1);//P2.1 interrupt enabledGPIO_enableInterrupt(GPIO_PORT_P2, GPIO_PIN1);  //使能中断//P2.1 Hi/Lo edgeGPIO_selectInterruptEdge(GPIO_PORT_P2, GPIO_PIN1, GPIO_HIGH_TO_LOW_TRANSITION); //设置中断类型//P2.1 IFG clearedGPIO_clearInterrupt(GPIO_PORT_P2, GPIO_PIN1);   //清除中断标志位
}void KEY_S2_Init(void)
{GPIO_setAsInputPinWithPullUpResistor(GPIO_PORT_P1, GPIO_PIN1);//P2.1 interrupt enabledGPIO_enableInterrupt(GPIO_PORT_P1, GPIO_PIN1);  //使能中断//P2.1 Hi/Lo edgeGPIO_selectInterruptEdge(GPIO_PORT_P1, GPIO_PIN1, GPIO_HIGH_TO_LOW_TRANSITION); //设置中断类型//P2.1 IFG clearedGPIO_clearInterrupt(GPIO_PORT_P1, GPIO_PIN1);   //清除中断标志位
}int main(void)
{WDT_A_hold(WDT_A_BASE);SystemClock_Init();Timer_A_PWM_Init();KEY_S1_Init();KEY_S2_Init();//interrupts enabled__bis_SR_register(GIE);while(1){}
}//******************************************************************************
//
//This is the PORT2_VECTOR interrupt vector service routine
//
//******************************************************************************
#pragma vector=PORT2_VECTOR     // P2口中断源
__interrupt
void Port_2 (void)              // 声明一个中断服务程序，名为Port_2()
{if(GPIO_getInterruptStatus(GPIO_PORT_P2, GPIO_PIN1)){delay_ms(20);if(!GPIO_getInputPinValue(GPIO_PORT_P2, GPIO_PIN1)){//P1.0 = toggleTimer_A_setCompareValue(TIMER_A0_BASE,TIMER_A_CAPTURECOMPARE_REGISTER_1,Timer_A_getCaptureCompareCount(TIMER_A0_BASE, TIMER_A_CAPTURECOMPARE_REGISTER_1) - TIMER_PERIOD / 10);while(!GPIO_getInputPinValue(GPIO_PORT_P2, GPIO_PIN1));}//P2.1 IFG clearedGPIO_clearInterrupt(GPIO_PORT_P2, GPIO_PIN1);}
}//******************************************************************************
//
//This is the PORT1_VECTOR interrupt vector service routine
//
//******************************************************************************
#pragma vector=PORT1_VECTOR     // P2口中断源
__interrupt
void Port_1 (void)              // 声明一个中断服务程序，名为Port_1()
{if(GPIO_getInterruptStatus(GPIO_PORT_P1, GPIO_PIN1)){delay_ms(20);if(!GPIO_getInputPinValue(GPIO_PORT_P1, GPIO_PIN1)){//P1.0 = toggleTimer_A_setCompareValue(TIMER_A0_BASE,TIMER_A_CAPTURECOMPARE_REGISTER_1,Timer_A_getCaptureCompareCount(TIMER_A0_BASE, TIMER_A_CAPTURECOMPARE_REGISTER_1) + TIMER_PERIOD / 10);while(!GPIO_getInputPinValue(GPIO_PORT_P1, GPIO_PIN1));}//P2.1 IFG clearedGPIO_clearInterrupt(GPIO_PORT_P1, GPIO_PIN1);}
}

效果

2.单定时器产生多路PWM信号

初始化函数

#define TIMER_PERIOD 12500
void Timer_A_PWM_Init(void)
{
//复用P1.2、P1.3、P1.4、P1.5输出GPIO_setAsPeripheralModuleFunctionOutputPin(GPIO_PORT_P1, GPIO_PIN2|GPIO_PIN3|GPIO_PIN4|GPIO_PIN5);Timer_A_initUpModeParam htim = {0};htim.clockSource = TIMER_A_CLOCKSOURCE_SMCLK;htim.clockSourceDivider = TIMER_A_CLOCKSOURCE_DIVIDER_40;htim.timerPeriod = TIMER_PERIOD - 1;htim.timerInterruptEnable_TAIE = TIMER_A_TAIE_INTERRUPT_DISABLE;htim.captureCompareInterruptEnable_CCR0_CCIE = TIMER_A_CCIE_CCR0_INTERRUPT_DISABLE;htim.timerClear = TIMER_A_DO_CLEAR;htim.startTimer = true;Timer_A_initUpMode(TIMER_A0_BASE, &htim);Timer_A_initCompareModeParam htim_PWM = {0};htim_PWM.compareInterruptEnable = TIMER_A_CAPTURECOMPARE_INTERRUPT_DISABLE;htim_PWM.compareOutputMode = TIMER_A_OUTPUTMODE_RESET_SET;htim_PWM.compareRegister = TIMER_A_CAPTURECOMPARE_REGISTER_1;htim_PWM.compareValue = (int)(TIMER_PERIOD * 0.2);//Initialize compare mode to generate PWM1Timer_A_initCompareMode(TIMER_A0_BASE, &htim_PWM);htim_PWM.compareRegister = TIMER_A_CAPTURECOMPARE_REGISTER_2;htim_PWM.compareValue = (int)(TIMER_PERIOD * 0.4);//Initialize compare mode to generate PWM2Timer_A_initCompareMode(TIMER_A0_BASE, &htim_PWM);htim_PWM.compareRegister = TIMER_A_CAPTURECOMPARE_REGISTER_3;htim_PWM.compareValue = (int)(TIMER_PERIOD * 0.6);//Initialize compare mode to generate PWM3Timer_A_initCompareMode(TIMER_A0_BASE, &htim_PWM);htim_PWM.compareRegister = TIMER_A_CAPTURECOMPARE_REGISTER_4;htim_PWM.compareValue = (int)(TIMER_PERIOD * 0.8);//Initialize compare mode to generate PWM4Timer_A_initCompareMode(TIMER_A0_BASE, &htim_PWM);}

依次将TA0.1、TA0.2、TA0.3、TA0.4初始化为占空比20%、40%、60%、80%，
时钟源为SMCLK = 25MHz
分频系数为40
装载值为12500 - 1
故所得PWM频率为25MHz/40/12500=50Hz

实验结果

3.对称PWM信号的产生

初始化程序

将上一个程稍作修改，即可产生对称PWM信号
其中compareOutputMode值的效果参考下图

时钟源为SMCLK = 25MHz
分频系数为40
装载值为12500 - 1
因采用增\减计数模式
故所得PWM频率为25MHz/40/12500/2=25Hz

#define TIMER_PERIOD 12500
void Timer_A_PWM_Init(void)
{GPIO_setAsPeripheralModuleFunctionOutputPin(GPIO_PORT_P1, GPIO_PIN2|GPIO_PIN3|GPIO_PIN4|GPIO_PIN5);Timer_A_initUpDownModeParam htim = {0};htim.clockSource = TIMER_A_CLOCKSOURCE_SMCLK;htim.clockSourceDivider = TIMER_A_CLOCKSOURCE_DIVIDER_40;htim.timerPeriod = TIMER_PERIOD - 1;htim.timerInterruptEnable_TAIE = TIMER_A_TAIE_INTERRUPT_DISABLE;htim.captureCompareInterruptEnable_CCR0_CCIE = TIMER_A_CCIE_CCR0_INTERRUPT_DISABLE;htim.timerClear = TIMER_A_DO_CLEAR;htim.startTimer = true;Timer_A_initUpDownMode(TIMER_A0_BASE, &htim);Timer_A_initCompareModeParam htim_PWM = {0};htim_PWM.compareInterruptEnable = TIMER_A_CAPTURECOMPARE_INTERRUPT_DISABLE;htim_PWM.compareOutputMode = TIMER_A_OUTPUTMODE_TOGGLE_RESET;htim_PWM.compareRegister = TIMER_A_CAPTURECOMPARE_REGISTER_1;htim_PWM.compareValue = (int)(TIMER_PERIOD * 0.2);//Initialize compare mode to generate PWM1Timer_A_initCompareMode(TIMER_A0_BASE, &htim_PWM);htim_PWM.compareRegister = TIMER_A_CAPTURECOMPARE_REGISTER_2;htim_PWM.compareValue = (int)(TIMER_PERIOD * 0.4);//Initialize compare mode to generate PWM2Timer_A_initCompareMode(TIMER_A0_BASE, &htim_PWM);htim_PWM.compareRegister = TIMER_A_CAPTURECOMPARE_REGISTER_3;htim_PWM.compareValue = (int)(TIMER_PERIOD * 0.6);//Initialize compare mode to generate PWM3Timer_A_initCompareMode(TIMER_A0_BASE, &htim_PWM);htim_PWM.compareRegister = TIMER_A_CAPTURECOMPARE_REGISTER_4;htim_PWM.compareValue = (int)(TIMER_PERIOD * 0.8);//Initialize compare mode to generate PWM4Timer_A_initCompareMode(TIMER_A0_BASE, &htim_PWM);
}

实验结果