Only deque from the USBtoSerial's USB->USART buffer when the USART is idle.

[pub/USBasp.git] / LUFA / Drivers / Peripheral / XMEGA / Serial_XMEGA.h

diff --git a/LUFA/Drivers/Peripheral/XMEGA/Serial_XMEGA.h b/LUFA/Drivers/Peripheral/XMEGA/Serial_XMEGA.h
index e337b31..e7f9fee 100644 (file)
--- a/LUFA/Drivers/Peripheral/XMEGA/Serial_XMEGA.h
+++ b/LUFA/Drivers/Peripheral/XMEGA/Serial_XMEGA.h
@@ -1,13 +1,13 @@
 /*
              LUFA Library
 /*
              LUFA Library

-     Copyright (C) Dean Camera, 2013.
+     Copyright (C) Dean Camera, 2014.

 
   dean [at] fourwalledcubicle [dot] com
            www.lufa-lib.org
 */
 
 /*
 
   dean [at] fourwalledcubicle [dot] com
            www.lufa-lib.org
 */
 
 /*

-  Copyright 2013  Dean Camera (dean [at] fourwalledcubicle [dot] com)
+  Copyright 2014  Dean Camera (dean [at] fourwalledcubicle [dot] com)

 
   Permission to use, copy, modify, distribute, and sell this
   software and its documentation for any purpose is hereby granted
 
   Permission to use, copy, modify, distribute, and sell this
   software and its documentation for any purpose is hereby granted


@@ -216,8 +216,37 @@
                                return ((USART->STATUS & USART_RXCIF_bm) ? true : false);
                        }
 
                                return ((USART->STATUS & USART_RXCIF_bm) ? true : false);
                        }
 

+                       /** Indicates whether there is hardware buffer space for a new transmit on the USART. This
+                        *  function can be used to determine if a call to \ref Serial_SendByte() will block in advance.
+                        *
+                        *  \param[in,out] USART  Pointer to the base of the USART peripheral within the device.
+                        *
+                        *  \return Boolean \c true if a character can be queued for transmission immediately, \c false otherwise.
+                        */
+                       static inline bool Serial_IsSendReady(USART_t* const USART) ATTR_ALWAYS_INLINE ATTR_WARN_UNUSED_RESULT ATTR_NON_NULL_PTR_ARG(1);
+                       static inline bool Serial_IsSendReady(USART_t* const USART)
+                       {
+                               return (USART->STATUS & USART_DREIF_bm) ? true : false);
+                       }
+
+                       /** Indicates whether the hardware USART transmit buffer is completely empty, indicating all
+                        *  pending transmissions have completed.
+                        *
+                        *  \param[in,out] USART  Pointer to the base of the USART peripheral within the device.
+                        *
+                        *  \return Boolean \c true if no characters are buffered for transmission, \c false otherwise.
+                        */
+                       static inline bool Serial_IsSendComplete(USART_t* const USART) ATTR_ALWAYS_INLINE ATTR_WARN_UNUSED_RESULT ATTR_NON_NULL_PTR_ARG(1);
+                       static inline bool Serial_IsSendComplete(USART_t* const USART)
+                       {
+                               return (USART->STATUS & USART_TCXIF_bm) ? true : false);
+                       }
+

                        /** Transmits a given byte through the USART.
                         *
                        /** Transmits a given byte through the USART.
                         *

+                        *  \note If no buffer space is available in the hardware USART, this function will block. To check if
+                        *        space is available before calling this function, see \ref Serial_IsSendReady().
+                        *

                         *  \param[in,out] USART     Pointer to the base of the USART peripheral within the device.
                         *  \param[in]     DataByte  Byte to transmit through the USART.
                         */
                         *  \param[in,out] USART     Pointer to the base of the USART peripheral within the device.
                         *  \param[in]     DataByte  Byte to transmit through the USART.
                         */


@@ -226,7 +255,7 @@
                        static inline void Serial_SendByte(USART_t* const USART,
                                                           const char DataByte)
                        {
                        static inline void Serial_SendByte(USART_t* const USART,
                                                           const char DataByte)
                        {

-                               while (!(USART->STATUS & USART_DREIF_bm));
+                               while (!(Serial_IsSendReady(USART));

                                USART->DATA = DataByte;
                        }
 
                                USART->DATA = DataByte;
                        }