EFM32片内外设Timer之PWM输出

Timer除了可以作为一个基本的定时器之外，也可以作为一个PWM输出模块。

硬件：TG STK， 利用PD7 即 TIMER1, CC1, #4来输出一个PWM波形。

软件例程如下：

#include "efm32.h"

#include "efm32_cmu.h"

#include "efm32_emu.h"

#include "efm32_gpio.h"

#include "efm32_prs.h"

#include "efm32_system.h"

#include "efm32_timer.h"

#include "efm32_chip.h"

/* Define TOP value */

#define TOP 1000 //TOP值设置PWM的周期

#define HIGHPULSE 800 //HIGHPULSE设置占空比

/**************************************************************************//**

* @brief Main function

* Main is called from __iar_program_start, see assembly startup file

*****************************************************************************/

int main(void)

{

/* Initialize chip */

CHIP_Init();



/* Enable clock for GPIO module */

CMU_ClockEnable(cmuClock_GPIO, true);



/* Enable clock for TIMER0 module */

CMU_ClockEnable(cmuClock_TIMER1, true);



/* Set CC1 location 4 pin (PD7) as output */

GPIO_PinModeSet(gpioPortD, 7, gpioModePushPull, 0);



/* Select CC channel parameters */

TIMER_InitCC_TypeDef timerCCInit =

{

.eventCtrl = timerEventEveryEdge,

.edge = timerEdgeBoth,

.prsSel = timerPRSSELCh0,

.cufoa = timerOutputActionNone,

.cofoa = timerOutputActionNone,

.cmoa = timerOutputActionToggle,

.mode = timerCCModePWM,

.filter = false,

.prsInput = false,

.coist = false,

.outInvert = false,

};



/* Configure CC channel 1 */

TIMER_InitCC(TIMER1, 1, &timerCCInit);

/* Route CC1 to location 4 (PD7) and enable pin */

TIMER1->ROUTE |= (TIMER_ROUTE_CC1PEN | TIMER_ROUTE_LOCATION_LOC4);



/* Set Top Value */

TIMER_TopSet(TIMER1, TOP);



TIMER_CompareBufSet(TIMER1, 1, HIGHPULSE);

/* Select timer parameters */

TIMER_Init_TypeDef timerInit =

{

.enable = true,

.debugRun = true,

.prescale = timerPrescale64,

.clkSel = timerClkSelHFPerClk,

.fallAction = timerInputActionNone,

.riseAction = timerInputActionNone,

.mode = timerModeUp,

.dmaClrAct = false,

.quadModeX4 = false,

.oneShot = false,

.sync = false,

};



/* Configure timer */

TIMER_Init(TIMER1, &timerInit);



while(1)

{



}



}