STM8S GPIO self-study notes

STM8S105C6T6 48 pins 32KB Flash Package: LQFP temp: -40~85

PA1~PA6,PB0~PB7,PC1~PC7,PD0~PD7,PE0~PE3,PE5~PE7,PG0,PG1,

There are a total of 38 general-purpose I/O ports.

GPIO Registers

Port x Output Data Register (Px_ODR);

Port x input data register (Px_IDR);

Port x output data direction (Px_DDR); 0: input mode 1: output mode;

Port x Control Register 1 (Px_CR1);

When DDR=1; set to 0 for analog open-drain output; set to 1 for push-pull output; (CR2 bit is used for output slew rate control);

When DDR=0; set to 0 floating input; set to 1 pull-up input;

Port x Control Register 2 (Px_CR2);

When DDR=0; set to 0 to disable external interrupt; set to 1 to enable external interrupt;

When DDR=1; set 0 speed 2MHz; set 1 speed 10MHz;

Corresponding GPIO library functions

void GPIO_DeInit(GPIO_TypeDef* GPIOx);

Used to restore the register of the specified port to the default value, 0x00; non-interrupt function floating input.

void GPIO_Init(GPIO_TypeDef* GPIOx, GPIO_Pin_TypeDef GPIO_Pin, GPIO_Mode_TypeDef GPIO_Mode);

GPIO initialization, configuration of specified port functions

GPIO_Pin：

GPIO_PIN_0 ~GPIO_PIN_7;
GPIO_PIN_HNIB; //High four pins

GPIO_PIN_LNIB; //lower four pins

GPIO_PIN_ALL ; //All pins

GPIO_Mode: input and output mode settings;

void GPIO_Write(GPIO_TypeDef* GPIOx, u8 PortVal);

Write value to the corresponding GPIO output.

void GPIO_WriteHigh(GPIO_TypeDef* GPIOx, GPIO_Pin_TypeDef PortPins);

Sets one or more pins of the specified port and outputs a high level, provided that the port is configured in output mode.

void GPIO_WriteLow(GPIO_TypeDef* GPIOx, GPIO_Pin_TypeDef PortPins);

Sets one or more pins of the specified port and outputs a low level, provided that the port is configured in output mode.

void GPIO_WriteReverse(GPIO_TypeDef* GPIOx, GPIO_Pin_TypeDef PortPins);

Negate the level state of one or more pins of the specified port and output them, provided that the port is configured in output mode.

u8 GPIO_ReadInputData(GPIO_TypeDef* GPIOx);

Read the specified port data and return an 8-bit unsigned value. The prerequisite is that the port is configured in input mode.

u8 GPIO_ReadOutputData(GPIO_TypeDef* GPIOx);

Read the value of the specified port output register and return an 8-bit unsigned value.

BitStatus GPIO_ReadInputPin(GPIO_TypeDef* GPIOx, GPIO_Pin_TypeDef GPIO_Pin);

Read the status of one or more pins of the specified port. If any pin is high, it returns SET, otherwise it returns RESET.

void GPIO_ExternalPullUpConfig(GPIO_TypeDef* GPIOx, GPIO_Pin_TypeDef GPIO_Pin, FunctionalState NewState);

Pin to enable or disable the internal pull-up resistor.

The STM8S series can be programmed using library functions or by directly manipulating registers.

Library function version of GPIO lights up LED (IAR FOR STM8S)

#include "stm8s.h"
#define uint unsigned int
void Delay(uint xms)
{
  uint i,j;
  for(i=xms;i>0;i--)
   for(j=220;j>0;j--);
}

void main()
{
  
   GPIO_Init( GPIOD,GPIO_PIN_0,GPIO_MODE_OUT_PP_HIGH_FAST);

  GPIO_WriteHigh(GPIOD,GPIO_PIN_0);
   Delay(500);
  GPIO_WriteLow(GPIOD,GPIO_PIN_0);
   Delay(500);
   while(1);
 

}

void assert_failed(u8* file, u32 line)
 {
   while (1)
   {
   }
 }