原理圖：
看著LED翻轉(zhuǎn)
頭文件及完整例程下載：http://www.torrancerestoration.com/f/stm32標(biāo)準(zhǔn)例程庫(kù)函數(shù).rar
程序分析：
#include "led.h"
#include "delay.h"
#include "key.h"
#include "sys.h"
#include "usart.h"
#include "timer.h"
//STM32開(kāi)發(fā)板實(shí)驗(yàn)8
//定時(shí)器中斷實(shí)驗(yàn)
int main(void)
{
delay_init(); //延時(shí)函數(shù)初始化
NVIC_Configuration(); //設(shè)置NVIC中斷分組2:2位搶占優(yōu)先級(jí)，2位響應(yīng)優(yōu)先級(jí)
// uart_init(9600); //串口初始化為9600
LED_Init(); //LED端口初始化
TIM3_Int_Init(4999,7199);//10Khz的計(jì)數(shù)頻率，計(jì)數(shù)到5000為500ms
while(1)
{
LED0=!LED0;
delay_ms(200);
}
}
重點(diǎn)分析： TIM3_Int_Init(4999,7199);//10Khz的計(jì)數(shù)頻率，計(jì)數(shù)到5000為500ms
void TIM3_Int_Init(u16 arr,u16 psc)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); //時(shí)鐘使能
//定時(shí)器TIM3初始化
TIM_TimeBaseStructure.TIM_Period = arr; //設(shè)置在下一個(gè)更新事件裝入活動(dòng)的自動(dòng)重裝載寄存器周期的值
TIM_TimeBaseStructure.TIM_Prescaler =psc; //設(shè)置用來(lái)作為T(mén)IMx時(shí)鐘頻率除數(shù)的預(yù)分頻值
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1; //設(shè)置時(shí)鐘分割:TDTS = Tck_tim
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上計(jì)數(shù)模式
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); //根據(jù)指定的參數(shù)初始化TIMx的時(shí)間基數(shù)單位
TIM_ITConfig(TIM3,TIM_IT_Update,ENABLE ); //使能指定的TIM3中斷,允許更新中斷
//中斷優(yōu)先級(jí)NVIC設(shè)置
NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn; //TIM3中斷
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; //先占優(yōu)先級(jí)0級(jí)
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3; //從優(yōu)先級(jí)3級(jí)
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道被使能
NVIC_Init(&NVIC_InitStructure); //初始化NVIC寄存器
TIM_Cmd(TIM3, ENABLE); //使能TIMx
}
//定時(shí)器3中斷服務(wù)程序
void TIM3_IRQHandler(void) //TIM3中斷
{
if (TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET) //檢查T(mén)IM3更新中斷發(fā)生與否
{
TIM_ClearITPendingBit(TIM3, TIM_IT_Update ); //清除TIMx更新中斷標(biāo)志
LED1=!LED1;
}
}
