STM8 IO external interrupt setting problem

STM8 IO external interrupt setting problem (using library function)

STM8, fall into the pit:

In the program, first enable the general interrupt, enableInterrupts(); // Enable the general interrupt  

In the subsequent program, set the IO port external interrupt to open and set the trigger level. The code is as follows: (The pit is here, pay attention!!!)

GPIO_Init(PORT_BLE_STA, PIN_BLE_STA, GPIO_Mode_In_PU_IT); //Pull up, open interrupt

EXTI_SetPinSensitivity(EXTI_PIN_BLE_STA, EXTI_Trigger_Falling); //Falling edge interrupt

Then the tragedy happened. Once a falling edge occurred at the IO port, the program died immediately and the watchdog was reset.

After locating, it was found that the interrupt was triggered continuously. But why was the interrupt triggered continuously? Wasn't it set to the falling edge interrupt?

reason:

Because the general interrupt has been turned on when setting the trigger level, the setting is invalid!!! This means that the falling edge trigger is not set at all!!! Then the default value is used, which is low level trigger. When the IO port is pulled low, the interrupt will be triggered continuously.

Solution: Be sure to set the level trigger when the general interrupt is turned off.

If you don't need interrupts at the beginning, you can disable IO port interrupts, but you need to set the trigger level first. When you need interrupts later, just turn on the interrupts, and you don't need to set the trigger level again.

example:

1. No interrupt is needed at the beginning, IO interrupt is disabled, but the trigger level must be set

GPIO_Init(PORT_BLE_STA, PIN_BLE_STA, GPIO_Mode_In_PU_No_IT);

EXTI_SetPinSensitivity(EXTI_PIN_BLE_STA, EXTI_Trigger_Falling); //When setting the trigger mode, be sure to turn off the total interrupt, otherwise it will fail

2. In the subsequent programs, you need to enable interrupts. Just turn on the IO interrupts. There is no need to set the trigger level here.

   GPIO_Init(PORT_BLE_STA, PIN_BLE_STA, GPIO_Mode_In_PU_IT);