STM8 line interrupt and port interrupt

There are two modes of STM8L interrupts, namely Pin mode and Port mode, which are the so-called line interrupts and port interrupts.

In short, line interrupt means that the interrupts of the same pin of all register groups use the same interrupt number, such as,

void KEY2Init()

{

  PB_DDR_bit.DDR2 = 0; //GPB->PIN2 Set the input and output direction register of port PB->2 to input direction 

  PB_CR1_bit.C12 = 1; //GPB->PIN2 input with pull-up resistor

  PB_CR2_bit.C22 = 1; //GPB->PIN2 enables external interrupt

                            // Use the second port as interrupt so select P2Is 

  EXTI_CR1_bit.P2IS = 2; //10 tx port bit2 external interrupt line 2 is a falling edge triggered interrupt

  EXTI_CONF_bit.PBLIS = 0; //Set PB[3:0] as the lower 4 bits of the external general interrupt PB port

}

Port interrupt means that all the pins of the same or multiple register groups use the same interrupt number.

void KEY3Init()

{

  PD_DDR_bit.DDR3 = 0; //GPD->PIN3 Set port PD->3 input direction

  PD_CR1_bit.C13 = 1; //GPD->PIN3 input with pull-up resistor

  PD_CR2_bit.C23 = 1; //GPD->PIN3 enables external interrupt

  EXTI_CR3_bit.PDIS = 2; //PortD port external interrupt line 2 is a falling edge triggered interrupt

  EXTI_CONF_bit.PDLIS = 1; //Set PD as external general interrupt

}

For example,

The interrupt of Pin1 of all Port A/B/C/D/E is EXTI1.

All pin interrupts of Port B and Port G are EXTIB/G

It can be understood that line interruption is specific to that pin, and port interruption is specific to that port.

A type of port can contain many pins.

When written in register mode, the two are very similar, with the following difference (please look carefully at the following two lines of code):

 1. EXTI_CR1_bit.P2IS = 2; //10 tx port bit2 external interrupt line 2 is a falling edge triggered interrupt

 2. EXTI_CR3_bit.PDIS = 2; //PortD port external interrupt line 2 is a falling edge triggered interrupt