Posted on May 05, 2014 at 18:31I want to set falling egde interrupt for PA15. I did below setting, but problem is interrupt occurs on both edges.
Pin is pulled up by 2.7K register to 5V.
I debug the code RTSR register has bit15 = 0, i.e rising edge disabled.
Didn't change RTSR & FTSR anywhere else in code.
void EXTI15_10_IRQHandler(void)
{
/* clear isr flag */
EXTI->PR = REG32_BIT_15;
// do something
}
void init()
{
/* make as input encoder I */
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_15;
GPIO_Init(GPIOA, &GPIO_InitStructure);
SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOA, EXTI_PinSource15);
EXTI->PR = REG32_BIT_15;
EXTI->FTSR = (0xFF800000U & EXTI->FTSR) | REG32_BIT_15;
EXTI->IMR = (0xFF800000U & EXTI->IMR) | REG32_BIT_15;
/* Enable and set EXTI Line2 Interrupt to the lowest priority */
NVIC_InitStructure.NVIC_IRQChannel = EXTI15_10_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x00;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
