STMicroelectronics STM8 Manual page 64

Code Example
#include "STM8S.h"
void clock_setup(void);
void GPIO_setup(void);
void IWDG_setup(void);
void main(void)
{
unsigned int t = 0;
clock_setup();
GPIO_setup();
GPIO_WriteLow(GPIOD, GPIO_PIN_0);
for(t = 0; t < 60000; t++);
IWDG_setup();
while(TRUE)
{
GPIO_WriteReverse(GPIOD, GPIO_PIN_0);
for(t = 0; t < 1000; t++)
{
}
};
}
void clock_setup(void)
{
CLK_DeInit();
CLK_HSECmd(DISABLE);
CLK_LSICmd(ENABLE);
while(CLK_GetFlagStatus(CLK_FLAG_LSIRDY) == FALSE);
CLK_HSICmd(ENABLE);
while(CLK_GetFlagStatus(CLK_FLAG_HSIRDY) == FALSE);
CLK_ClockSwitchCmd(ENABLE);
CLK_HSIPrescalerConfig(CLK_PRESCALER_HSIDIV8);
CLK_SYSCLKConfig(CLK_PRESCALER_CPUDIV4);
CLK_ClockSwitchConfig(CLK_SWITCHMODE_AUTO, CLK_SOURCE_HSI,
DISABLE, CLK_CURRENTCLOCKSTATE_ENABLE);
CLK_PeripheralClockConfig(CLK_PERIPHERAL_SPI, DISABLE);
CLK_PeripheralClockConfig(CLK_PERIPHERAL_I2C, DISABLE);
CLK_PeripheralClockConfig(CLK_PERIPHERAL_ADC, DISABLE);
CLK_PeripheralClockConfig(CLK_PERIPHERAL_AWU, DISABLE);
CLK_PeripheralClockConfig(CLK_PERIPHERAL_UART1, DISABLE);
CLK_PeripheralClockConfig(CLK_PERIPHERAL_TIMER1, DISABLE);
CLK_PeripheralClockConfig(CLK_PERIPHERAL_TIMER2, DISABLE);
CLK_PeripheralClockConfig(CLK_PERIPHERAL_TIMER4, DISABLE);
}
if(GPIO_ReadInputPin(GPIOB, GPIO_PIN_7) == FALSE)
{
IWDG_WriteAccessCmd(IWDG_WriteAccess_Enable);
IWDG_ReloadCounter();
IWDG_WriteAccessCmd(IWDG_WriteAccess_Disable);
}