diff --git a/bsp/stm32f0x/drivers/usart.c b/bsp/stm32f0x/drivers/usart.c
index 0c4aa15821..56e39f1c94 100644
--- a/bsp/stm32f0x/drivers/usart.c
+++ b/bsp/stm32f0x/drivers/usart.c
@@ -97,8 +97,9 @@ static int stm32_putc(struct rt_serial_device *serial, char c)
     RT_ASSERT(serial != RT_NULL);
     uart = (struct stm32_uart *)serial->parent.user_data;
 
-    while (!(uart->uart_device->ISR & USART_FLAG_TXE));
+    USART_ClearFlag(uart->uart_device,USART_FLAG_TC);
     uart->uart_device->TDR = c;
+    while (!(uart->uart_device->ISR & USART_FLAG_TC));
 
     return 1;
 }
diff --git a/bsp/stm32f107/drivers/usart.c b/bsp/stm32f107/drivers/usart.c
index c1bdd1b9be..e6a7d59535 100644
--- a/bsp/stm32f107/drivers/usart.c
+++ b/bsp/stm32f107/drivers/usart.c
@@ -124,6 +124,7 @@ static int stm32_putc(struct rt_serial_device *serial, char c)
     RT_ASSERT(serial != RT_NULL);
     uart = (struct stm32_uart *)serial->parent.user_data;
 
+    USART_ClearFlag(uart->uart_device,USART_FLAG_TC);
     uart->uart_device->DR = c;
     while (!(uart->uart_device->SR & USART_FLAG_TC));
 
diff --git a/bsp/stm32f10x-HAL/drivers/drv_usart.c b/bsp/stm32f10x-HAL/drivers/drv_usart.c
index 2650469921..bd6b6cd984 100644
--- a/bsp/stm32f10x-HAL/drivers/drv_usart.c
+++ b/bsp/stm32f10x-HAL/drivers/drv_usart.c
@@ -113,8 +113,9 @@ static int stm32_putc(struct rt_serial_device *serial, char c)
     struct stm32_uart *uart;
     RT_ASSERT(serial != RT_NULL);
     uart = (struct stm32_uart *)serial->parent.user_data;
-    while (__HAL_UART_GET_FLAG(&uart->huart, UART_FLAG_TXE) == RESET);
+    __HAL_UART_CLEAR_FLAG(&(uart->huart), UART_FLAG_TC);
     uart->huart.Instance->DR = c;
+    while (__HAL_UART_GET_FLAG(&(uart->huart), UART_FLAG_TC) == RESET);
     return 1;
 }
 
diff --git a/bsp/stm32f10x/drivers/usart.c b/bsp/stm32f10x/drivers/usart.c
index 18059bf1dc..b3960d749a 100644
--- a/bsp/stm32f10x/drivers/usart.c
+++ b/bsp/stm32f10x/drivers/usart.c
@@ -100,8 +100,6 @@ static rt_err_t stm32_configure(struct rt_serial_device *serial, struct serial_c
 
     /* Enable USART */
     USART_Cmd(uart->uart_device, ENABLE);
-    
-    USART_ClearFlag(uart->uart_device,USART_FLAG_TC);
 
     return RT_EOK;
 }
@@ -159,6 +157,7 @@ static int stm32_putc(struct rt_serial_device *serial, char c)
     }
     else
     {
+        USART_ClearFlag(uart->uart_device,USART_FLAG_TC);
         uart->uart_device->DR = c;
         while (!(uart->uart_device->SR & USART_FLAG_TC));
     }
diff --git a/bsp/stm32f40x/drivers/usart.c b/bsp/stm32f40x/drivers/usart.c
index 0633c82cdd..bd8ea3239b 100644
--- a/bsp/stm32f40x/drivers/usart.c
+++ b/bsp/stm32f40x/drivers/usart.c
@@ -166,8 +166,9 @@ static int stm32_putc(struct rt_serial_device *serial, char c)
     RT_ASSERT(serial != RT_NULL);
     uart = (struct stm32_uart *)serial->parent.user_data;
 
-    while (!(uart->uart_device->SR & USART_FLAG_TXE));
+    USART_ClearFlag(uart->uart_device,USART_FLAG_TC);
     uart->uart_device->DR = c;
+    while (!(uart->uart_device->SR & USART_FLAG_TC));
 
     return 1;
 }
diff --git a/bsp/stm32f411-nucleo/drivers/drv_usart.c b/bsp/stm32f411-nucleo/drivers/drv_usart.c
index a0a0088694..dacd1490eb 100644
--- a/bsp/stm32f411-nucleo/drivers/drv_usart.c
+++ b/bsp/stm32f411-nucleo/drivers/drv_usart.c
@@ -155,8 +155,9 @@ static int drv_putc(struct rt_serial_device *serial, char c)
     RT_ASSERT(serial != RT_NULL);
     uart = (struct drv_uart *)serial->parent.user_data;
     
-    while((__HAL_UART_GET_FLAG(&uart->UartHandle, UART_FLAG_TXE) == RESET));
+    __HAL_UART_CLEAR_FLAG(&(uart->UartHandle), UART_FLAG_TC);
     uart->UartHandle.Instance->DR = c;
+    while (__HAL_UART_GET_FLAG(&(uart->UartHandle), UART_FLAG_TC) == RESET);
     return 1;
 }
 
diff --git a/bsp/stm32f429-apollo/drivers/usart.c b/bsp/stm32f429-apollo/drivers/usart.c
index ecca8b7307..5ed0100dc3 100644
--- a/bsp/stm32f429-apollo/drivers/usart.c
+++ b/bsp/stm32f429-apollo/drivers/usart.c
@@ -185,8 +185,9 @@ static int stm32_putc(struct rt_serial_device *serial, char c)
     RT_ASSERT(serial != RT_NULL);
     uart = (struct stm32_uart *)serial->parent.user_data;
 
-    while((__HAL_UART_GET_FLAG(&uart->UartHandle, UART_FLAG_TXE) == RESET));
+    __HAL_UART_CLEAR_FLAG(&(uart->UartHandle), UART_FLAG_TC);
     uart->UartHandle.Instance->DR = c;
+    while (__HAL_UART_GET_FLAG(&(uart->UartHandle), UART_FLAG_TC) == RESET);
     return 1;
 }
 
diff --git a/bsp/stm32f429-armfly/drivers/usart.c b/bsp/stm32f429-armfly/drivers/usart.c
index ecca8b7307..5ed0100dc3 100644
--- a/bsp/stm32f429-armfly/drivers/usart.c
+++ b/bsp/stm32f429-armfly/drivers/usart.c
@@ -185,8 +185,9 @@ static int stm32_putc(struct rt_serial_device *serial, char c)
     RT_ASSERT(serial != RT_NULL);
     uart = (struct stm32_uart *)serial->parent.user_data;
 
-    while((__HAL_UART_GET_FLAG(&uart->UartHandle, UART_FLAG_TXE) == RESET));
+    __HAL_UART_CLEAR_FLAG(&(uart->UartHandle), UART_FLAG_TC);
     uart->UartHandle.Instance->DR = c;
+    while (__HAL_UART_GET_FLAG(&(uart->UartHandle), UART_FLAG_TC) == RESET);
     return 1;
 }
 
diff --git a/bsp/stm32f429-disco/drivers/usart.c b/bsp/stm32f429-disco/drivers/usart.c
index f7ba2ed277..7509cbf64c 100644
--- a/bsp/stm32f429-disco/drivers/usart.c
+++ b/bsp/stm32f429-disco/drivers/usart.c
@@ -185,8 +185,9 @@ static int stm32_putc(struct rt_serial_device *serial, char c)
     RT_ASSERT(serial != RT_NULL);
     uart = (struct stm32_uart *)serial->parent.user_data;
 
-    while((__HAL_UART_GET_FLAG(&uart->UartHandle, UART_FLAG_TXE) == RESET));
+    __HAL_UART_CLEAR_FLAG(&(uart->UartHandle), UART_FLAG_TC);
     uart->UartHandle.Instance->DR = c;
+    while (__HAL_UART_GET_FLAG(&(uart->UartHandle), UART_FLAG_TC) == RESET);
     return 1;
 }
 
diff --git a/bsp/stm32f4xx-HAL/drivers/drv_usart.c b/bsp/stm32f4xx-HAL/drivers/drv_usart.c
index db3321ab34..083cdfc39b 100644
--- a/bsp/stm32f4xx-HAL/drivers/drv_usart.c
+++ b/bsp/stm32f4xx-HAL/drivers/drv_usart.c
@@ -122,8 +122,9 @@ static int drv_putc(struct rt_serial_device *serial, char c)
     struct drv_uart *uart;
     RT_ASSERT(serial != RT_NULL);
     uart = (struct drv_uart *)serial->parent.user_data;
-    while ((__HAL_UART_GET_FLAG(&uart->UartHandle, UART_FLAG_TXE) == RESET));
+    __HAL_UART_CLEAR_FLAG(&(uart->UartHandle), UART_FLAG_TC);
     uart->UartHandle.Instance->DR = c;
+    while (__HAL_UART_GET_FLAG(&(uart->UartHandle), UART_FLAG_TC) == RESET);
     return 1;
 }
 
diff --git a/bsp/stm32f7-disco/drivers/drv_usart.c b/bsp/stm32f7-disco/drivers/drv_usart.c
index 5d54d6903b..2c15fafc29 100644
--- a/bsp/stm32f7-disco/drivers/drv_usart.c
+++ b/bsp/stm32f7-disco/drivers/drv_usart.c
@@ -106,7 +106,7 @@ static int drv_putc(struct rt_serial_device *serial, char c)
     struct drv_uart *uart;
     RT_ASSERT(serial != RT_NULL);
     uart = (struct drv_uart *)serial->parent.user_data;
-    while ((__HAL_UART_GET_FLAG(&uart->UartHandle, UART_FLAG_TXE) == RESET));
+    __HAL_UART_CLEAR_FLAG(&(uart->UartHandle), UART_FLAG_TC);
     uart->UartHandle.Instance->TDR = c;
     return 1;
 }
diff --git a/bsp/stm32h743-nucleo/drivers/drv_usart.c b/bsp/stm32h743-nucleo/drivers/drv_usart.c
index e8620b65ee..26b624130e 100644
--- a/bsp/stm32h743-nucleo/drivers/drv_usart.c
+++ b/bsp/stm32h743-nucleo/drivers/drv_usart.c
@@ -138,8 +138,9 @@ static int stm32_putc(struct rt_serial_device *serial, char c)
     RT_ASSERT(serial != RT_NULL);
     uart = (struct stm32_uart *)serial->parent.user_data;
 
-    while (!(uart->UartHandle.Instance->ISR & UART_FLAG_TXE));
+    __HAL_UART_CLEAR_FLAG(&(uart->UartHandle), UART_FLAG_TC);
     uart->UartHandle.Instance->TDR = c;
+    while (__HAL_UART_GET_FLAG(&(uart->UartHandle), UART_FLAG_TC) == RESET);
 
     return 1;
 }
diff --git a/bsp/stm32l475-iot-disco/drivers/usart.c b/bsp/stm32l475-iot-disco/drivers/usart.c
index fa5a68e7cb..15f52ecedb 100644
--- a/bsp/stm32l475-iot-disco/drivers/usart.c
+++ b/bsp/stm32l475-iot-disco/drivers/usart.c
@@ -185,8 +185,9 @@ static int stm32_putc(struct rt_serial_device *serial, char c)
     RT_ASSERT(serial != RT_NULL);
     uart = (struct stm32_uart *)serial->parent.user_data;
 
-    while((__HAL_UART_GET_FLAG(&uart->UartHandle, UART_FLAG_TXE) == RESET));
+    __HAL_UART_CLEAR_FLAG(&(uart->UartHandle), UART_FLAG_TC);
     uart->UartHandle.Instance->TDR = c;
+    while (__HAL_UART_GET_FLAG(&(uart->UartHandle), UART_FLAG_TC) == RESET);
     return 1;
 }
 
diff --git a/bsp/stm32l476-nucleo/drivers/drv_usart.c b/bsp/stm32l476-nucleo/drivers/drv_usart.c
index c5f5e728a3..a4ec08db07 100644
--- a/bsp/stm32l476-nucleo/drivers/drv_usart.c
+++ b/bsp/stm32l476-nucleo/drivers/drv_usart.c
@@ -141,8 +141,9 @@ static int drv_putc(struct rt_serial_device *serial, char c)
 
     uart = (struct drv_uart *)serial->parent.user_data;
 
-    while ((__HAL_UART_GET_FLAG(&uart->UartHandle, UART_FLAG_TXE) == RESET));
+    __HAL_UART_CLEAR_FLAG(&(uart->UartHandle), UART_FLAG_TC);
     uart->UartHandle.Instance->TDR = c;
+    while (__HAL_UART_GET_FLAG(&(uart->UartHandle), UART_FLAG_TC) == RESET);
 
     return 1;
 }