issue in STM32F103XX TIM2

[mayurr]

Posted on August 07, 2008 at 02:55

issue in STM32F103XX TIM2

[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);

[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

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; } } }