issue in STM32F103XX TIM2

[mayurr]

Posted on August 07, 2008 at 02:55

issue in STM32F103XX TIM2

[16-32micros]

Posted on May 17, 2011 at 12:41

Hi mayurr,

Could you advive about your CPU/AHB and PCLK prescaler clocks in your example ? and what did you find in this particular configuration.

Cheers,

STOne-32.

[mayurr]

Posted on May 17, 2011 at 12:41

i have to geneate 0.005 ms timer interupt with tim2 .

any one tell me how to calculate precaler and preload value?

i have calulated but is it wrong ?

and what is the use of clock division ?

TIM_TimeBaseStructure.TIM_Period =160;

TIM_TimeBaseStructure.TIM_Prescaler =1124;

TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;

TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;

TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

/* Clear TIM2 update pending flag */

TIM_ClearFlag(TIM2, TIM_FLAG_Update);

/* TIM IT enable */

TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);

/* TIM2 enable counter */

TIM_Cmd(TIM2, ENABLE);

[mayurr]

Posted on May 17, 2011 at 12:41

sir,

I have to generate 0.005 ms tim2 interupt for stm32f103xx.

and i have to on -off LED after every 5s .

but it is not haappenibng in practical case.

in practical case

LED on-off very fast near about after every 2 sec .

can anyone give an idea where am i wrong?

my program :

GPIO_InitTypeDef GPIO_InitStructure;

NVIC_InitTypeDef NVIC_InitStructure;

TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;

#ifdef DEBUG

debug();

#endif

/* Configure the system clocks */

RCC_Configuration();

/* NVIC Configuration */

//NVIC_Configuration();

/* Configure PC0,PC1,PC2,PC3 output push-pull */

GPIO_DeInit(GPIOC);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0; //| GPIO_Pin_1| GPIO_Pin_2;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;

GPIO_Init(GPIOC, &GPIO_InitStructure); // PORT C as output

NVIC_DeInit();

NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQChannel;

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority =2;

NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00;

NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

NVIC_Init(&NVIC_InitStructure);

/* Time base configuration */

TIM_DeInit(TIM2);

TIM_TimeBaseStructure.TIM_Period =0xFFFF;

TIM_TimeBaseStructure.TIM_Prescaler =0x02;

TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;

TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;

TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

/* Clear TIM2 update pending flag */

TIM_ClearFlag(TIM2, TIM_FLAG_Update);

/* TIM IT enable */

TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);

/* TIM2 enable counter */

TIM_Cmd(TIM2, ENABLE);

while (1)

{

}

}

interupt timer routine:

void TIM2_IRQHandler(void)

{

static unsigned long Timer_Value=0;

if(Flag==0)

{

GPIO_SetBits(GPIOC,GPIO_Pin_0);

if(++Timer_Value==1000000)

{

Timer_Value=0;

Flag=1;

}

}

else

{

GPIO_ResetBits(GPIOC,GPIO_Pin_0);

if(++Timer_Value==1000000)

{

Timer_Value=0;

Flag=0;

}

}

}