原创 ST TIMx Example1 for mini board

 2008-4-13 10:21  3194 4 4 分类: MCU/ 嵌入式

本例使用了TIM2 Channel1, 2, 3 and 4 in Output, corresponding GPIOA0,1,2,3, and pin 10~13，所以可不用修改直接使用，还是遇到一些问题，先把大致的程序附录一下：

/General TIM: 16bit, 4 independent channels, TIM2,3,4 are normal Timer, TIM1 is advanced timer
//工作在输出比较模式
//Includes ------------------------------------------------------------------*/
#include "stm32f10x_lib.h"

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
vu16 CCR1_Val = 0x8000;
vu16 CCR2_Val = 0x4000;
vu16 CCR3_Val = 0x2000;
vu16 CCR4_Val = 0x1000;
ErrorStatus HSEStartUpStatus;

/* Private function prototypes -----------------------------------------------*/
void RCC_Configuration(void);
void GPIO_Configuration(void);
void NVIC_Configuration(void);

/* Private functions ---------------------------------------------------------*/

/*******************************************************************************
* Function Name : main
* Description    : Main program
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/
int main(void)
{
#ifdef DEBUG   // this DEBUG is defined in the "option - c complier - Preprocessor - Defined symbols"
debug();
#endif

/* System Clocks Configuration */
RCC_Configuration();

/* NVIC Configuration */
NVIC_Configuration();

/* GPIO Configuration */
GPIO_Configuration();

/* ---------------------------------------------------------------
TIM2 Configuration: Output Compare Toggle Mode:
TIM2CLK = 36 MHz, Prescaler = 0x2, TIM2 counter clock = 12 MHz 36/(2+1)MHz
CC1 update rate = TIM2 counter clock / CCR1_Val = 366.2 Hz 这是计时器＝比较寄存器事件的频率
CC2 update rate = TIM2 counter clock / CCR2_Val = 732.4 Hz
CC3 update rate = TIM2 counter clock / CCR3_Val = 1464.8 Hz
CC4 update rate = TIM2 counter clock / CCR4_Val = 2929.6 Hz
--------------------------------------------------------------- */

/* Time base configuration */
TIM_TimeBaseStructure.TIM_Period = 0xFFFF;

//period的值是设定计数器的最大值,从0数到这个值又返回0重新计数

TIM_TimeBaseStructure.TIM_Prescaler = 0x02;
//TIM_Prescaler:预分频器 TIMx 的计数器到时频率为TIMxCLK/(Prescaler+1)
TIM_TimeBaseStructure.TIM_ClockDivision = 0x0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; // up counting mode

TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

/* Output Compare Toggle Mode configuration: Channel1 */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle;
//output compare toggle mode 触发模式, 计数器与比较寄存器相同时,输出翻转
TIM_OCInitStructure.TIM_Channel = TIM_Channel_1;
TIM_OCInitStructure.TIM_Pulse = CCR1_Val;      //pulse value loaded in capture compare register
//Pulse=0x8000,即计数脉冲到0x8000时作操作(P148 参考手册),本例是输出从0-1或相反.
//12M/0x8000=366.2,而实际的波形频率为366.2/2=183.1Hz
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;

//TIM_OCPolarity就是设定CC1P的值, 为H就是输出不反相,为L就是输出反相。

圈中右边的梯形表示一个多路开关，多路开关受TIMx_CCER寄存器的CC1P位控制，CC1P=0时OC1REF不经反相直接输出，CC1P=1时先将OC1REF反相在输出。

TIM_OCInit(TIM2, &TIM_OCInitStructure);

TIM_OC1PreloadConfig(TIM2, TIM_OCPreload_Disable); //??? TIM2 preload register disable

......

/* TIM enable counter */
TIM_Cmd(TIM2, ENABLE);

/* TIM IT enable */
TIM_ITConfig(TIM2, TIM_IT_CC1 | TIM_IT_CC2 | TIM_IT_CC3 | TIM_IT_CC4, ENABLE);

while(1)
{
}
}

中断程序： stm32f10x_it.c

u16 capture = 0;
extern vu16 CCR1_Val; //"extern" tell the compiler the variant is defined in the other file
extern vu16 CCR2_Val;
extern vu16 CCR3_Val;
extern vu16 CCR4_Val;

/*******************************************************************************
* Function Name : TIM2_IRQHandler
* Description    : This function handles TIM2 global interrupt request.
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/
void TIM2_IRQHandler(void)
{
/* TIM2_CH1 toggling with frequency = 183.1 Hz */
if (TIM_GetITStatus(TIM2, TIM_IT_CC1) != RESET) //check which specific interrupt has occured
//if TIM_GetITStatus()==SET, interrupt happened
{ //TIM_IT_CC1 is capture/compare 1 interrupt source
    TIM_ClearITPendingBit(TIM2, TIM_IT_CC1 );     //clear the interrupt pending bit
capture = TIM_GetCapture1(TIM2);
//get the capture1 value (CCR1) of TIM2, 脉冲计数器的值即是与CCR1 的值比较，相等则触发TIMx事件
TIM_SetCompare1(TIM2, capture + CCR1_Val );
/*set capture/compare 1 register value，CCR1的值增加，使得下一个TIM事件也需要CCR1_Val个脉冲，另一种方式我想是清零脉冲计数器，*/
     //TIM_SetCounter(TIM2,0x0000);