Posted on June 14, 2013 at 14:52I have used APB1 = 30Mhz with 60Mhz to timer. I made following coed for TIM3. I have initialized the TIM3 interrupt.
void TIM3_IRQHandler(void)
{
TIM3->SR = 0x0000; /* clear update flag */
GPIOA->ODR ^= GPIO_Pin_7;
}
void config_TIM3()
{
TIM3->CR1 = 0x0084; /* No clock divder , ARR is buffered , update Event enabled */
TIM3->SR = 0x0000; /* clear interrupt flag */
TIM3->EGR = 0x0000; /* clear interrupt generation bit */
TIM3->DIER = 0x0001; /* enable interrupt flag */
TIM3->PSC = 0x0000; /* no prescaler */
TIM3->CNT = 0x00000000; /* */
TIM3->ARR = 0xffff;
TIM3->CR1 |= 0x0001; /* enable counter */
}
Problem is there is timing mismatch
I think I had not configured timer properly.
I am using formula delay_time = ( ARR * (PSC+1) )/PCLK
= (65535 * 1 ) / 60000000 = 1.09225 ms
I am getting 1.164ms.
For system_init() I have used ST clock config utility(excel sheet).
