STM32F103RBT6 串口硬件流控制无法正常通讯

jackey · 发表于 2018-4-19 13:44:37

目前在使用STM32F103RBT6芯片过程中，USART1串口部分需要使用4线制的硬件流控制进行通信，即TXD,RXD,RTS,CTS。两颗芯片硬件上按照规格书上进行连接，如下图：（包含连接方式和说明）

软件按照要求配置后，没有通讯起来，将硬件流控制功能关闭，芯片能够正常通信。
现在做了一个小程序进行测试，发送方的CTS与接收方RTS连接，发现上电后配置完作为接收方的RTS的管脚始终为高，发送方检测CTS一直为高，所以数据一直停止发送，导致无法通信。
使用官方历程和STM32CubeMX生成的工程效果一样，因此希望有调试过得人能够帮助一下，问题出在哪里？（理解，软件或是硬件连接）
以下是本人的代码内容：
/* Private typedef -----------------------------------------------------------*/
#define UART_BUF_LEN    (100 * 4)
#define UART_TIMEOUT    (100000)

typedef struct {
  uint32_t len;
  uint8_t  buf[UART_BUF_LEN];
} usart_data_typedef;

/* Private define ------------------------------------------------------------*/
//only one of two define
//#define HFC_SEND_DATA

#define TRG_GPIO_CLK    (RCC_APB2Periph_GPIOE)
#define TRG_GPIO_PORT    (GPIOE)
#define TRG_GPIO_PIN    (GPIO_Pin_0)

#define UART_GPIO_APB_CLK  (RCC_APB2Periph_GPIOA)
#define UART_GPIO_PORT    (GPIOA)
#define UART_GPIO_TX_PIN (GPIO_Pin_9)
#define UART_GPIO_RX_PIN (GPIO_Pin_10)
#define UART_GPIO_CTS_PIN  (GPIO_Pin_11)
#define UART_GPIO_RTS_PIN  (GPIO_Pin_12)

#define UART_APB_CLK    (RCC_APB2Periph_USART1)
#define UART_CLK_CTRL_FUNC (RCC_APB2PeriphClockCmd)
#define UARTx             (USART1)
#define UARTx_BANDRATE    (115200)
#define UARTx_IRQ       (USART1_IRQn)

/* Private macro -------------------------------------------------------------*/
#define TEST_Standby()    {GPIO_SetBits(TRG_GPIO_PORT, TRG_GPIO_PIN);}
#define TEST_Start()    {GPIO_ResetBits(TRG_GPIO_PORT, TRG_GPIO_PIN);}

/* Private variables ---------------------------------------------------------*/
usart_data_typedef uart_send;
usart_data_typedef uart_rec;
uint8_t const send_buf[17] = {0x10, 0x0F, 0xF0, 0x1E, 0xE1, 0x2D, 0xD2, 0x3C, 0xC3,
                           0x4B, 0xB4, 0x5A, 0xA5, 0x69, 0x96, 0x78, 0x87};

/* Private function prototypes -----------------------------------------------*/
/* Private functions ---------------------------------------------------------*/

/**
  * @brief  Main program
  * @param  None
  * @retval None
  */
int main(void)
{
  GPIO_InitTypeDef  GPIO_InitStructure;
  USART_InitTypeDef USART_InitStructure;
  NVIC_InitTypeDef  NVIC_InitStructure;

  uint32_t i;

  /* Enable all clock */
  RCC_PCLK2Config(RCC_HCLK_Div1);
  RCC_APB2PeriphClockCmd(TRG_GPIO_CLK, ENABLE);
  GPIO_DeInit(TRG_GPIO_PORT);
  RCC_APB2PeriphClockCmd(UART_GPIO_APB_CLK | RCC_APB2Periph_AFIO, ENABLE);
  GPIO_DeInit(UART_GPIO_PORT);
  RCC_PCLK1Config(RCC_HCLK_Div2);
  UART_CLK_CTRL_FUNC(UART_APB_CLK, ENABLE);
  USART_DeInit(UARTx);

  /* Set trigger gpio clock config */
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
  GPIO_InitStructure.GPIO_Pin = TRG_GPIO_PIN;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(TRG_GPIO_PORT, &GPIO_InitStructure);
  TEST_Standby();

  /* Configure USART RTS and USART Tx as alternate function push-pull */
  GPIO_InitStructure.GPIO_Pin = UART_GPIO_TX_PIN | UART_GPIO_RTS_PIN;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_Init(UART_GPIO_PORT, &GPIO_InitStructure);
  /* Configure USART CTS and USART Rx as input floating */
  GPIO_InitStructure.GPIO_Pin = UART_GPIO_CTS_PIN | UART_GPIO_RX_PIN;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
  GPIO_Init(UART_GPIO_PORT, &GPIO_InitStructure);

  /* USARTx configured as follow:
      - BaudRate = 115200 baud
      - Word Length = 8 Bits
      - One Stop Bit
      - No parity
      - Hardware flow control enabled (RTS and CTS signals) */
  USART_InitStructure.USART_BaudRate = UARTx_BANDRATE;
  USART_InitStructure.USART_WordLength = USART_WordLength_8b;
  USART_InitStructure.USART_StopBits = USART_StopBits_1;
  USART_InitStructure.USART_Parity = USART_Parity_No;
  USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_RTS_CTS;
  USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
  USART_Init(UARTx, &USART_InitStructure);
  USART_ClearFlag(UARTx, USART_FLAG_TC);
  USART_ClearFlag(UARTx, USART_FLAG_RXNE);
  USART_Cmd(UARTx, ENABLE);

  USART_ClearFlag(UARTx, USART_FLAG_TC);
  USART_ClearFlag(UARTx, USART_FLAG_RXNE);
  USART_ClearITPendingBit(UARTx, USART_IT_TC);
  USART_ClearITPendingBit(UARTx, USART_IT_RXNE);
  USART_ITConfig(UARTx, USART_IT_TC, ENABLE);
  USART_ITConfig(UARTx, USART_IT_RXNE, ENABLE);

  /* Set USARTx interrupt config */
  NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
  NVIC_InitStructure.NVIC_IRQChannel = UARTx_IRQ;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);

  uart_send.len = 0;
  uart_rec.len = 0;
  for (i = 0; i < UART_BUF_LEN; i++) {
uart_send.buf = 0;
uart_rec.buf = 0;
  }
  for (i = 0; i < sizeof(send_buf); i++) {
uart_send.buf = send_buf;
  }

  /* Start test */
  TEST_Start();
#ifdef HFC_SEND_DATA
  USART_SendData(UARTx, uart_send.buf[0]);
#endif

  while (1) {
  }
}

/**
  * @brief  USARTx interrupt program.
  * @param  None
  * @retval None
  */
void usartx_interrupt(void)
{
  uint32_t i;

  if (USART_GetITStatus(UARTx, USART_IT_RXNE) != RESET) {
/* Read one byte from the receive data register */
uart_rec.buf[uart_rec.len] = USART_ReceiveData(UARTx);
if (uart_rec.len == uart_rec.buf[0]) {
   for (i = 0; i < UART_BUF_LEN; i++) {
      uart_send.buf = uart_rec.buf;
   }
   uart_rec.len = 0;
   uart_send.len = 0;
   USART_SendData(UARTx, uart_send.buf[0]);
} else {
   uart_rec.len++;
}
  }

  if (USART_GetITStatus(UARTx, USART_IT_TC) != RESET) {
/* Write one byte to the transmit data register */
if (uart_send.len == uart_send.buf[0]) {
   USART_ClearITPendingBit(UARTx, USART_IT_TC);
   uart_send.len = 0;
} else {
   USART_SendData(UARTx, uart_send.buf[++uart_send.len]);
}
  }
}