Can one generate an interrupt from Port C pin 0 or pin 1 on the STM8L051F3?

[AClap.1]

There do not seem to be definitions for Port C to be used as such.

  //EXTI_SelectPort(EXTI_Port_C);

  //EXTI_SetHalfPortSelection(EXTI_HalfPort_C_LSB, ENABLE);

  //EXTI_SetPortSensitivity(EXTI_Port_C, EXTI_Trigger_Falling);

Is there any way to trigger a falling interrupt for input on Port C Pin 0 (pin 18 on the tssop 20 package)?

[AClap.1]

I am very interested if anyone else is able to make a port C pin 1 (or 0) generate an interrupt. In the STM8L051 datasheet, it says "Up to 18 I/Os, all mappable on interrupt vectors"... so I'm hopeful that it is possible. The absence of definitions for PORTC in the Port-based portions of EXTI in the SPL make me suspect it is possible, but that I must use EXTI0/EXTI1 directly with the pin.

Here is the skeleton of what I'm trying to do. It compiles and runs, but no interrupts are created when I toggle the input pin from an external source, and nothing is ever added to the Fifo. I know the Fifo works, as I've debugged it many other ways. Can anyone point me in the direction of what I may be missing or not understanding?

// Configure EXTI
void EXTI_Config(void) {
    GPIO_Init(GPIOC, GPIO_Pin_1, GPIO_Mode_In_FL_No_IT);
    EXTI_SetPinSensitivity(EXTI_Pin_1, EXTI_Trigger_Falling);
}
 
// int. handler ---- inputFifo is created as volatile
// TimingElapsed is a TIM3 based counter, like micros()
void EXTI1_IRQHandler() __interrupt(9) {
    uint32_t now = TimingElapsed;
    RINGFIFO_WR(inputFifo, (uint8_t)(now - then));
    then = now; 
    EXTI_ClearITPendingBit(EXTI_IT_Pin1);
}

[Cristian Gyorgy]

I know nothing of your circuit or software, but sure you can use PC0/1 for external interrupts.

[AClap.1]

Thank you Cristian. That is very good to hear. Do happen to have any idea why there are no definitions in the SPL for EXTI_Port_C, EXTI_HalfPort_C_LSB, etc., while there are defines for ports A,B,D-H ?

[Cristian Gyorgy]

I don't know the definitions in the tools you use, but it's probably a more general thing, not really 100% specific to STM8L051F3. Maybe they are missing as there is not port C specific interrupt, as for ports B & D (see interrupt vector table). In case you miss any definitions, just use the ones from the data sheet and the reference manual RM0031.