diff --git a/bsp/stm32/libraries/HAL_Drivers/drv_usart.c b/bsp/stm32/libraries/HAL_Drivers/drv_usart.c
index 13001b4bc0..e666df3733 100644
--- a/bsp/stm32/libraries/HAL_Drivers/drv_usart.c
+++ b/bsp/stm32/libraries/HAL_Drivers/drv_usart.c
@@ -98,6 +98,53 @@ static struct stm32_uart_config uart_config[] =
 
 static struct stm32_uart uart_obj[sizeof(uart_config) / sizeof(uart_config[0])] = {0};
 
+rt_uint32_t stm32_uart_get_mask(rt_uint32_t word_length, rt_uint32_t parity)
+{
+    rt_uint32_t mask = 0x00FFU;
+    if (word_length == UART_WORDLENGTH_8B)
+    {
+        if (parity == UART_PARITY_NONE)
+        {
+            mask = 0x00FFU ;
+        }
+        else
+        {
+            mask = 0x007FU ;
+        }
+    }
+#ifdef UART_WORDLENGTH_9B
+    else if (word_length == UART_WORDLENGTH_9B)
+    {
+        if (parity == UART_PARITY_NONE)
+        {
+            mask = 0x01FFU ;
+        }
+        else
+        {
+            mask = 0x00FFU ;
+        }
+    }
+#endif
+#ifdef UART_WORDLENGTH_7B
+    else if (word_length == UART_WORDLENGTH_7B)
+    {
+        if (parity == UART_PARITY_NONE)
+        {
+            mask = 0x007FU ;
+        }
+        else
+        {
+            mask = 0x003FU ;
+        }
+    }
+    else
+    {
+        mask = 0x0000U;
+    }
+#endif
+    return mask;
+}
+
 static rt_err_t stm32_configure(struct rt_serial_device *serial, struct serial_configure *cfg)
 {
     struct stm32_uart *uart;
@@ -182,6 +229,7 @@ static rt_err_t stm32_configure(struct rt_serial_device *serial, struct serial_c
     {
         return -RT_ERROR;
     }
+    uart->DR_mask = stm32_uart_get_mask(uart->handle.Init.WordLength, uart->handle.Init.Parity);
 
     return RT_EOK;
 }
@@ -257,52 +305,7 @@ static rt_err_t stm32_control(struct rt_serial_device *serial, int cmd, void *ar
     return RT_EOK;
 }
 
-rt_uint32_t stm32_uart_get_mask(rt_uint32_t word_length, rt_uint32_t parity)
-{
-    rt_uint32_t mask;
-    if (word_length == UART_WORDLENGTH_8B)
-    {
-        if (parity == UART_PARITY_NONE)
-        {
-            mask = 0x00FFU ;
-        }
-        else
-        {
-            mask = 0x007FU ;
-        }
-    }
-#ifdef UART_WORDLENGTH_9B
-    else if (word_length == UART_WORDLENGTH_9B)
-    {
-        if (parity == UART_PARITY_NONE)
-        {
-            mask = 0x01FFU ;
-        }
-        else
-        {
-            mask = 0x00FFU ;
-        }
-    }
-#endif
-#ifdef UART_WORDLENGTH_7B
-    else if (word_length == UART_WORDLENGTH_7B)
-    {
-        if (parity == UART_PARITY_NONE)
-        {
-            mask = 0x007FU ;
-        }
-        else
-        {
-            mask = 0x003FU ;
-        }
-    }
-    else
-    {
-        mask = 0x0000U;
-    }
-#endif
-    return mask;
-}
+
 
 static int stm32_putc(struct rt_serial_device *serial, char c)
 {
@@ -337,9 +340,9 @@ static int stm32_getc(struct rt_serial_device *serial)
     || defined(SOC_SERIES_STM32L0) || defined(SOC_SERIES_STM32G0) || defined(SOC_SERIES_STM32H7) || defined(SOC_SERIES_STM32L5) \
     || defined(SOC_SERIES_STM32G4) || defined(SOC_SERIES_STM32MP1) || defined(SOC_SERIES_STM32WB)|| defined(SOC_SERIES_STM32F3) \
     || defined(SOC_SERIES_STM32U5)
-        ch = uart->handle.Instance->RDR & stm32_uart_get_mask(uart->handle.Init.WordLength, uart->handle.Init.Parity);
+        ch = uart->handle.Instance->RDR & uart->DR_mask;
 #else
-        ch = uart->handle.Instance->DR & stm32_uart_get_mask(uart->handle.Init.WordLength, uart->handle.Init.Parity);
+        ch = uart->handle.Instance->DR & uart->DR_mask;
 #endif
     }
     return ch;
diff --git a/bsp/stm32/libraries/HAL_Drivers/drv_usart.h b/bsp/stm32/libraries/HAL_Drivers/drv_usart.h
index 80d06b5030..cc6aa66b8a 100644
--- a/bsp/stm32/libraries/HAL_Drivers/drv_usart.h
+++ b/bsp/stm32/libraries/HAL_Drivers/drv_usart.h
@@ -57,6 +57,7 @@ struct stm32_uart
 {
     UART_HandleTypeDef handle;
     struct stm32_uart_config *config;
+    rt_uint32_t DR_mask;
 
 #ifdef RT_SERIAL_USING_DMA
     struct