stm8s: GPIO configuration, light up the LED! PB4, PB5 pin LEDs do not light up

I have been developing STM8S103 for the past two days. After adjusting the hardware, I started to write the software. The first step was to light up the LED light. It turned out to be embarrassing that it just wouldn't light up! Later, I searched Baidu and carefully checked the data sheet, only to find a big pitfall. Due to carelessness, I didn't see it and made a note as a reminder.

1. Process

To light up the LED, the process is basically the same as that of STM32:

(1) Configure GPIO (STM8S does not require the clock of each pin to be configured specifically, and the system clock can be configured at the beginning)

(2) GPIO output high and low levels

Without further ado, let's get straight to the code:

2. Code

//FUNCKTION: Initialize the LED light GPIO port

//PARA: None

//RETURN : None

void LED_Config() 

{

    GPIO_Init(GPIOB, GPIO_PIN_5, GPIO_MODE_OUT_PP_LOW_SLOW);

    GPIO_Init(GPIOB, GPIO_PIN_4, GPIO_MODE_OUT_PP_LOW_SLOW);

}

//FUNCKTION: Turn on the LED light

//PARA: None

//RETURN : None

void LED_ON()

{

    GPIO_WriteHigh(GPIOB, GPIO_PIN_4);

    GPIO_WriteHigh(GPIOB, GPIO_PIN_5);

}

//FUNCKTION: Turn off the LED light

//PARA: None

//RETURN : None

void LED_OFF()

{

    GPIO_WriteLow(GPIOB, GPIO_PIN_4);

    GPIO_WriteLow(GPIOB, GPIO_PIN_5);

}

3. The problem of LED not lighting up no matter how hard you try

Because the two GPIO ports *PB4 and PB5 are used, the following figure can be seen in the data sheet: 

You can see that the GPIO port marked in the red circle is T(3). Continue scrolling down to the bottom of the table to see the description of T(3): 

I'm not good at English, so I won't translate it. Anyway, the meaning is that you need to add pull-up or pull-down resistors externally, otherwise it will be useless.

So, I quickly found a wire, made a line, connected a resistor, and it was done. ~~~Haha. . .