STM32F0 PA9输出pwm

根据提供的引用内容，可以看出PA9并没有被用作PWM输出。但是，我们可以通过修改引用中的代码来将PA9设置为PWM输出。具体步骤如下：

1. 配置PA9引脚为复用推挽输出模式，具体代码如下：

   GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
   GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
   GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
   GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
   GPIO_Init(GPIOA, &GPIO_InitStructure);

2. 配置TIM1_CH2通道为PWM输出模式，具体代码如下：

   TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
   TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
   TIM_OCInitStructure.TIM_Pulse = 0;
   TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
   TIM_OC2Init(TIM1, &TIM_OCInitStructure);
   TIM_OC2PreloadConfig(TIM1, TIM_OCPreload_Enable);

3. 启动TIM1定时器，具体代码如下：

   TIM_Cmd(TIM1, ENABLE);

4. 启动TIM1_CH2通道的PWM输出，具体代码如下：

   TIM_CtrlPWMOutputs(TIM1, ENABLE);

完整的代码如下：

#include "stm32f0xx.h"

void TIM_IO_Config(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    TIM_OCInitTypeDef TIM_OCInitStructure;

    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    GPIO_PinAFConfig(GPIOA, GPIO_PinSource9, GPIO_AF_2);

    TIM_TimeBaseStructure.TIM_Period = 999;
    TIM_TimeBaseStructure.TIM_Prescaler = 47;
    TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);

    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_Pulse = 0;
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OC2Init(TIM1, &TIM_OCInitStructure);
    TIM_OC2PreloadConfig(TIM1, TIM_OCPreload_Enable);

    TIM_Cmd(TIM1, ENABLE);
    TIM_CtrlPWMOutputs(TIM1, ENABLE);
}

int main(void)
{
    TIM_IO_Config();

    while (1)
    {
    }
}