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[/] [openrisc/] [trunk/] [rtos/] [freertos-6.1.1/] [Demo/] [dsPIC_MPLAB/] [serial/] [serial.c] - Blame information for rev 592

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1 592 jeremybenn
/*
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    FreeRTOS V6.1.1 - Copyright (C) 2011 Real Time Engineers Ltd.
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    ***************************************************************************
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    *                                                                         *
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    * If you are:                                                             *
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    *                                                                         *
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    *    + New to FreeRTOS,                                                   *
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    *    + Wanting to learn FreeRTOS or multitasking in general quickly       *
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    *    + Looking for basic training,                                        *
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    *    + Wanting to improve your FreeRTOS skills and productivity           *
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    *                                                                         *
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    * then take a look at the FreeRTOS books - available as PDF or paperback  *
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    *                                                                         *
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    *        "Using the FreeRTOS Real Time Kernel - a Practical Guide"        *
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    *                  http://www.FreeRTOS.org/Documentation                  *
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    *                                                                         *
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    * A pdf reference manual is also available.  Both are usually delivered   *
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    * to your inbox within 20 minutes to two hours when purchased between 8am *
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    * and 8pm GMT (although please allow up to 24 hours in case of            *
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    * exceptional circumstances).  Thank you for your support!                *
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    *                                                                         *
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    ***************************************************************************
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    This file is part of the FreeRTOS distribution.
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    FreeRTOS is free software; you can redistribute it and/or modify it under
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    the terms of the GNU General Public License (version 2) as published by the
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    Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
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    ***NOTE*** The exception to the GPL is included to allow you to distribute
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    a combined work that includes FreeRTOS without being obliged to provide the
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    source code for proprietary components outside of the FreeRTOS kernel.
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    FreeRTOS is distributed in the hope that it will be useful, but WITHOUT
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    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
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    more details. You should have received a copy of the GNU General Public
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    License and the FreeRTOS license exception along with FreeRTOS; if not it
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    can be viewed here: http://www.freertos.org/a00114.html and also obtained
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    by writing to Richard Barry, contact details for whom are available on the
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    FreeRTOS WEB site.
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    1 tab == 4 spaces!
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    http://www.FreeRTOS.org - Documentation, latest information, license and
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    contact details.
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    http://www.SafeRTOS.com - A version that is certified for use in safety
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    critical systems.
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    http://www.OpenRTOS.com - Commercial support, development, porting,
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    licensing and training services.
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*/
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/* BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER.
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NOTE:  This driver is primarily to test the scheduler functionality.  It does
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not effectively use the buffers or DMA and is therefore not intended to be
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an example of an efficient driver. */
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/* Standard include file. */
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#include <stdlib.h>
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/* Scheduler include files. */
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#include "FreeRTOS.h"
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#include "queue.h"
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#include "task.h"
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/* Demo app include files. */
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#include "serial.h"
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/* Hardware setup. */
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#define serOUTPUT                                               0
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#define serINPUT                                                1
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#define serLOW_SPEED                                    0
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#define serONE_STOP_BIT                                 0
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#define serEIGHT_DATA_BITS_NO_PARITY    0
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#define serNORMAL_IDLE_STATE                    0
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#define serAUTO_BAUD_OFF                                0
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#define serLOOPBACK_OFF                                 0
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#define serWAKE_UP_DISABLE                              0
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#define serNO_HARDWARE_FLOW_CONTROL             0
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#define serSTANDARD_IO                                  0
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#define serNO_IRDA                                              0
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#define serCONTINUE_IN_IDLE_MODE                0
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#define serUART_ENABLED                                 1
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#define serINTERRUPT_ON_SINGLE_CHAR             0
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#define serTX_ENABLE                                    1
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#define serINTERRUPT_ENABLE                             1
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#define serINTERRUPT_DISABLE                    0
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#define serCLEAR_FLAG                                   0
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#define serSET_FLAG                                             1
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/* The queues used to communicate between tasks and ISR's. */
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static xQueueHandle xRxedChars;
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static xQueueHandle xCharsForTx;
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static portBASE_TYPE xTxHasEnded;
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/*-----------------------------------------------------------*/
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xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
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{
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char cChar;
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        /* Create the queues used by the com test task. */
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        xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
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        xCharsForTx = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
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        /* Setup the UART. */
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        U2MODEbits.BRGH         = serLOW_SPEED;
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        U2MODEbits.STSEL        = serONE_STOP_BIT;
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        U2MODEbits.PDSEL        = serEIGHT_DATA_BITS_NO_PARITY;
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        U2MODEbits.ABAUD        = serAUTO_BAUD_OFF;
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        U2MODEbits.LPBACK       = serLOOPBACK_OFF;
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        U2MODEbits.WAKE         = serWAKE_UP_DISABLE;
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        U2MODEbits.UEN          = serNO_HARDWARE_FLOW_CONTROL;
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        U2MODEbits.IREN         = serNO_IRDA;
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        U2MODEbits.USIDL        = serCONTINUE_IN_IDLE_MODE;
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        U2MODEbits.UARTEN       = serUART_ENABLED;
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        U2BRG = (unsigned short)(( (float)configCPU_CLOCK_HZ / ( (float)16 * (float)ulWantedBaud ) ) - (float)0.5);
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        U2STAbits.URXISEL       = serINTERRUPT_ON_SINGLE_CHAR;
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        U2STAbits.UTXEN         = serTX_ENABLE;
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        U2STAbits.UTXINV        = serNORMAL_IDLE_STATE;
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        U2STAbits.UTXISEL0      = serINTERRUPT_ON_SINGLE_CHAR;
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        U2STAbits.UTXISEL1      = serINTERRUPT_ON_SINGLE_CHAR;
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        /* It is assumed that this function is called prior to the scheduler being
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        started.  Therefore interrupts must not be allowed to occur yet as they
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        may attempt to perform a context switch. */
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        portDISABLE_INTERRUPTS();
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        IFS1bits.U2RXIF = serCLEAR_FLAG;
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        IFS1bits.U2TXIF = serCLEAR_FLAG;
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        IPC7bits.U2RXIP = configKERNEL_INTERRUPT_PRIORITY;
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        IPC7bits.U2TXIP = configKERNEL_INTERRUPT_PRIORITY;
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        IEC1bits.U2TXIE = serINTERRUPT_ENABLE;
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        IEC1bits.U2RXIE = serINTERRUPT_ENABLE;
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        /* Clear the Rx buffer. */
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        while( U2STAbits.URXDA == serSET_FLAG )
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        {
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                cChar = U2RXREG;
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        }
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        xTxHasEnded = pdTRUE;
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        return NULL;
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}
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/*-----------------------------------------------------------*/
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signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, portTickType xBlockTime )
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{
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        /* Only one port is supported. */
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        ( void ) pxPort;
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        /* Get the next character from the buffer.  Return false if no characters
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        are available or arrive before xBlockTime expires. */
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        if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
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        {
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                return pdTRUE;
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        }
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        else
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        {
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                return pdFALSE;
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        }
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}
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/*-----------------------------------------------------------*/
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signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, portTickType xBlockTime )
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{
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        /* Only one port is supported. */
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        ( void ) pxPort;
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        /* Return false if after the block time there is no room on the Tx queue. */
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        if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
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        {
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                return pdFAIL;
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        }
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        /* A critical section should not be required as xTxHasEnded will not be
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        written to by the ISR if it is already 0 (is this correct?). */
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        if( xTxHasEnded )
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        {
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                xTxHasEnded = pdFALSE;
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                IFS1bits.U2TXIF = serSET_FLAG;
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        }
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        return pdPASS;
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}
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/*-----------------------------------------------------------*/
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void vSerialClose( xComPortHandle xPort )
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{
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}
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/*-----------------------------------------------------------*/
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void __attribute__((__interrupt__, auto_psv)) _U2RXInterrupt( void )
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{
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char cChar;
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portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
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        /* Get the character and post it on the queue of Rxed characters.
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        If the post causes a task to wake force a context switch as the woken task
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        may have a higher priority than the task we have interrupted. */
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        IFS1bits.U2RXIF = serCLEAR_FLAG;
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        while( U2STAbits.URXDA )
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        {
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                cChar = U2RXREG;
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                xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
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        }
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        if( xHigherPriorityTaskWoken != pdFALSE )
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        {
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                taskYIELD();
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        }
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}
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/*-----------------------------------------------------------*/
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void __attribute__((__interrupt__, auto_psv)) _U2TXInterrupt( void )
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{
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signed char cChar;
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portBASE_TYPE xTaskWoken = pdFALSE;
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        /* If the transmit buffer is full we cannot get the next character.
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        Another interrupt will occur the next time there is space so this does
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        not matter. */
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        IFS1bits.U2TXIF = serCLEAR_FLAG;
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        while( !( U2STAbits.UTXBF ) )
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        {
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                if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xTaskWoken ) == pdTRUE )
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                {
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                        /* Send the next character queued for Tx. */
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                        U2TXREG = cChar;
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                }
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                else
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                {
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                        /* Queue empty, nothing to send. */
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                        xTxHasEnded = pdTRUE;
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                        break;
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                }
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        }
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        if( xTaskWoken != pdFALSE )
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        {
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                taskYIELD();
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        }
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}
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