如何使用STM32中的寄存器配置SWD引脚？

Question

Info：我使用STM32中的寄存器创建Blink。这可以工作，除了固件之后SWD连接器对我停止工作。原因最可能是SWD与LED放在同一端口上。配置端口和LED引脚时，我可能会重置SWD设置。

代码：

#include "main.h"

void SystemClock_Config(void);

int main(void)
{
  HAL_Init();
  SystemClock_Config();

  __HAL_RCC_GPIOA_CLK_ENABLE();
  // Set PA8 to OUTPUT mode
  GPIOA->MODER = 0x00010000;
  // Set PUSH-PULL mode
  GPIOA->OTYPER = 0x00000000;
  // Set pin speed
  GPIOA->OSPEEDR = 0x64010000;
  // Set not pull
  GPIOA->PUPDR = 0x64000000;
  // Set pin bit
  GPIOA->BSRR = 0x00000100;

  static int pin_state = 0;

  while (1)
  {
      // LED blink
      if(pin_state == 0) {
        // Bit set
        GPIOA->BSRR = 0x00000100;
        pin_state = 1;
      } else {
        // Bit clear
        GPIOA->BSRR = 0x01000000;
        pin_state = 0;
      }

      HAL_Delay(3000);

  }
}

void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** Initializes the CPU, AHB and APB busses clocks 
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }
  /** Initializes the CPU, AHB and APB busses clocks 
  */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
  {
    Error_Handler();
  }
}

void Error_Handler(void) {}

#ifdef  USE_FULL_ASSERT
void assert_failed(char *file, uint32_t line) {}
#endif

在STM32F334K8Tx数据表中，我没有找到太多有关设置SWD触点寄存器的信息（哪种模式，设置时钟，上拉等）。

问题：这怎么办？或在哪里可以找到信息？

Answer 1

而不是使用幻数，您应该使用类似的东西：

// Set PA8 to OUTPUT mode
GPIOA->MODER |= GPIO_MODER_MODER8_1; // Ref.: 9.4.1
// Set PUSH-PULL mode
//GPIOA->OTYPER = 0x00000000; // Reset value is 0x0000 0000
// Set pin speed
//GPIOA->OSPEEDR = 0x6401 0000;
GPIOA->OSPEEDR |= GPIO_OSPEEDR_OSPEEDR8_0; // 9.4.3

// Set not pull
//GPIOA->PUPDR  // Reset value is: 0x6400 0000 9.4.4
// Set pin bit
GPIOA->BSRR |= GPIO_BSRR_BS_8; // 9.4.7

在循环中，您可以使用：

// The BSRR register is read only
GPIOA->BSRR |= GPIO_BSRR_BS_8; // set ON
GPIOA->BSRR |= GPIO_BSRR_BR_8; // reset
// You could also use:
GPIOA->BRR |= GPIO_BSRR_BS_8; // set ON 9.4.11

如果您想重置寄存器，请使用类似的内容：

GPIOA->PUPDR &= ~GPIO_PUPDR_PUPDR8_1; // reset the value