我正在STM32F103C6上编程UART。我编写了下面的代码，但是当我尝试它时，它不起作用。谁能帮我找出我的错误吗？

Question

我正在使用C语言在STM32F103C6上使用BAREMETAL对UART进行编程。但是，当我在Proteus软件中对其进行模拟时，它不起作用！我使用 HAL 制作了另一个程序，完成了这项工作，但没有使用 BAREMETAL 中的代码。谁能帮我找出我的错误吗？

#include "stm32f103x6.h"

#define USART2EN        (1U<<17)
#define GPIOAEN         (1U<<2)
#define CR1_UE          (1U<<13)
#define CR1_M           (1U<<12)
#define CR1_TE          (1U<<3)
#define CR1_RE          (1U<<2)
#define SR_TXE          (1U<<7)
#define SR_RXNE         (1U<<5)
#define SR_TC           (1U<<6)
#define BAUDRATE        115200
#define APB1_FREQ       8000000

/*Função que configura o clock*/
void SysClockConfig(void)
{
    /***********>>>> PASSO A PASSO <<<<***********
     * 1. ENABLE HSI and wait to become ready internal 8 MHz RC Oscillator
     * 2. Set the POWER ENABLE CLOCK
     * 3. Configure the PRESCALERS MCLK, PCLK1, PCLK2 (peripheral clocks)
     **********************************************/

    //1. ENABLE HSE and wait for the MSE to become ready (external crystal)
    RCC->CR |= RCC_CR_HSION; // habilita o clock externo
    while (!(RCC->CR & RCC_CR_HSIRDY)){} // quer dizer que o oscilador estar pronto

    //2. Set the POWER ENABLE CLOCK
    RCC->APB1ENR |= RCC_APB1ENR_PWREN;

    //Desabilita o PLL primeiro
    RCC->CR &=~ (1U<<24);
    while (!(RCC->CR & (1U<<25))){} // aguarda ate o PLL ser desligado

    //Configura o PLL para HSI/2 * 2 = 8Mhz (sendo o HSI = 8MHz)

    RCC->CFGR &= ~(RCC_CFGR_PLLSRC | RCC_CFGR_PLLMULL); // primeiro zera os bits
    // Deixa os bits 18 a 21  PLLMUL = 0000 = PLL input clock x 2
    RCC->CFGR &=~ (1U<<18);
    RCC->CFGR &=~ (1U<<19);
    RCC->CFGR &=~ (1U<<20);
    RCC->CFGR &=~ (1U<<21);
    // Deixa o bit 16 PLLSRC = 0 = HSI oscillator clock / 2 selected as PLL input clock
    RCC->CFGR &=~ (1U<<16);

    //Habilita o PLL
    RCC->CR |= (1U<<24);
    while (RCC->CR & (1U<<25)){} // aguarda ate o PLL estar pronto


    //3. Configurar os PRESCALERS AHB, APB1 e APB2 (peripheral clocks)
    //AHB PR
    RCC->CFGR |= RCC_CFGR_HPRE_DIV1; // divide por 1
    //APB1 PR
    RCC->CFGR |= RCC_CFGR_PPRE1_DIV1;// divide por 1
    //APB2 PR
    RCC->CFGR |= RCC_CFGR_PPRE2_DIV1;// divide por 1


    // Seleciona o clock do sistema para PLL
    RCC->CFGR &=~ RCC_CFGR_SW;
    RCC->CFGR |= RCC_CFGR_SW_PLL;

    while ((RCC->CFGR & RCC_CFGR_SWS) != RCC_CFGR_SWS_PLL); // Espera ate que o PLL seja selecionado como clock

}

接下来我进行了 UART 设置

void uart2_tx_init(void)
{
    /*** CONFIGURA O GPIOA QUE É ONDE ESTA CONECTADO O TX DO UART2 ***/

    /* 1- Habilitar o sinal de clock ao GPIO A*/
    RCC->APB2ENR |= GPIOAEN;

    /*Configurar o PA2 (TX) e PA3 (RX)*/
    //PA2
    GPIOA->CRL &=~(GPIO_CRL_CNF2 | GPIO_CRL_MODE2 | GPIO_CRL_CNF3 | GPIO_CRL_MODE3);
    GPIOA->CRL &=~(1U<<8);//seta bit 8 para 0
    GPIOA->CRL |= (1U<<9);//seta bit 9 para 1
    GPIOA->CRL &=~ (1U<<10);//seta bit 10 para 0
    GPIOA->CRL |= (1U<<11);//seta bit 11 para 1

    //PA3
    GPIOA->CRL &=~(1U<<12);//seta bit 12 para 0
    GPIOA->CRL |= (1U<<13);//seta bit 13 para 1
    GPIOA->CRL &=~ (1U<<14);//seta bit 14 para 0
    GPIOA->CRL |= (1U<<15);//seta bit 15 para 1


    /*** CONFIGURA O PERIFERICO UART ***/

    /* 1- Habilitar o sinal de clock ao periferico UART2*/
    RCC->APB1ENR |= USART2EN;

    /*Habilitar o USART no registrador de controle*/
    USART2->CR1 |= CR1_UE;

    /*Seleciona para 1 Start bit, 8 Data bits, n Stop bit */
    USART2->CR1 &=~ CR1_M;

    /*Numero de Stop bits em 1*/
    USART2->CR2 &=~ (1U<<12);
    USART2->CR2 &=~ (1U<<13);

    /*Configura o Baud Rate com fclk de 8Mhz e bd 1500*/
    USART2->BRR = (5U<<0) | (4U<<4);//(unsigned)(APB1_FREQ/BAUDRATE);

    /*Habilita a transferencia (Tx) ->  to send an idle frame as first transmission.*/
    USART2->CR1 |= CR1_TE;

    /*Habilida o recebimento*/
    USART2->CR1 |= CR1_RE;

}

在里面我做了可以发送和接收的功能

void UART2_SendChar(int ch)
{
    while (!(USART2->SR & SR_TXE)){}

    USART2->DR = (ch & 0xFF);

}



char UART2_ReceiveChar(void)
{
    while (!(USART2->SR & SR_RXNE)); // Espera até receber um caractere

    return USART2->DR; // Retorna o caractere recebido
}


int main (void)
{
    SysClockConfig();
    uart2_tx_init();

    while(1)
    {
        UART2_SendChar('m');
    }

}

Answer 1

可以使用STM32CubeIDE调试SMT32F103C6（BluePill）吗？我的 MCU 是假的，我不确定是否可以直接在 STM32CubeIDE 上进行调试。如果有人知道怎么做，可以给我解释一下吗？