关于PWM 求助

momodewo1212 · 发表于 2013-5-14 16:38:59

#include "pwm_output.h"

static void TIM4_GPIO_Config(void)
{
GPIO_InitTypeDef GPIO_InitStructure;

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD, ENABLE);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_15 ;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_Init(GPIOD, &GPIO_InitStructure);

}

static void TIM4_Mode_Config(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;

u16 CCR1_Val = 500;

TIM_TimeBaseStructure.TIM_Period = 999;
TIM_TimeBaseStructure.TIM_Prescaler = 0;
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1 ;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;

TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure);

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR1_Val;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;

TIM_OC4Init(TIM4, &TIM_OCInitStructure);

TIM_OC4PreloadConfig(TIM4, TIM_OCPreload_Enable);

TIM_ARRPreloadConfig(TIM4, ENABLE);

TIM_Cmd(TIM4, ENABLE);
}

void TIM4_PWM_Init(void)
{
TIM4_GPIO_Config();
TIM4_Mode_Config();
}

这就是把一个例程改了下输出到PD15脚 TIM4_CH4上了怎么就不能输出方波了呢