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276 lines
9.4 KiB
C
276 lines
9.4 KiB
C
/*
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FreeRTOS V7.0.2 - Copyright (C) 2011 Real Time Engineers Ltd.
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***************************************************************************
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* *
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* FreeRTOS tutorial books are available in pdf and paperback. *
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* Complete, revised, and edited pdf reference manuals are also *
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* available. *
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* *
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* Purchasing FreeRTOS documentation will not only help you, by *
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* ensuring you get running as quickly as possible and with an *
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* in-depth knowledge of how to use FreeRTOS, it will also help *
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* the FreeRTOS project to continue with its mission of providing *
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* professional grade, cross platform, de facto standard solutions *
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* for microcontrollers - completely free of charge! *
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* *
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* >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
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* *
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* Thank you for using FreeRTOS, and 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 modification to the GPL is included to allow you to
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distribute a combined work that includes FreeRTOS without being obliged to
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provide the source code for proprietary components outside of the FreeRTOS
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kernel. FreeRTOS is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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or 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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/*
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BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR UART0.
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*NOTE* - This file is designed to test some of the RTOS features - it is
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not intended to represent an efficient implementation!
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*/
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/* Standard includes. */
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#include <stdlib.h>
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/* Scheduler includes. */
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#include "FreeRTOS.h"
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#include "queue.h"
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/* Demo application includes. */
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#include "serial.h"
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/* Hardware specifics. */
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#define serRX_DATA_PIN ( 0x01 )
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#define serTX_DATA_PIN ( 0x02 )
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#define serCLOCK_Fxx_DIV_8 0x03
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#define serUPWR ( 0x80 )
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#define serUTXE ( 0x40 )
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#define serURXE ( 0x20 )
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#define serUCL ( 0x02 )
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#define serLSB ( 0x10 )
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/* Misc. */
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#define serINVALID_QUEUE ( ( xQueueHandle ) 0 )
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#define serHANDLE ( ( xComPortHandle ) 1 )
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#define serNO_BLOCK ( ( portTickType ) 0 )
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/*-----------------------------------------------------------*/
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/* Queues used to hold received characters, and characters waiting to be
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transmitted. */
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static xQueueHandle xRxedChars;
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static xQueueHandle xCharsForTx;
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/*-----------------------------------------------------------*/
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/* Interrupt entry point written in the assembler file serialISR.s85. */
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extern void vSerialISREntry( void );
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/* Flag to indicate whether or not there are characters already queued to send. */
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static volatile unsigned long ulTxInProgress = pdFALSE;
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/*-----------------------------------------------------------*/
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/*
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* See the serial2.h header file.
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*/
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xComPortHandle xSerialPortInitMinimal( unsigned portLONG ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
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{
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xComPortHandle xReturn = serHANDLE;
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const unsigned portLONG ulFuclk = ( configCPU_CLOCK_HZ / 2 ) / 8UL;
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/* Create the queues used to hold Rx and Tx characters. */
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xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
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xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
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/* If the queues were created correctly then setup the serial port
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hardware. */
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if( ( xRxedChars != serINVALID_QUEUE ) && ( xCharsForTx != serINVALID_QUEUE ) )
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{
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portENTER_CRITICAL();
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{
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/* Set the UART0 Rx and Tx pins to their alternative function. */
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PMC3 |= ( serRX_DATA_PIN | serTX_DATA_PIN );
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PM3 &= ~( serTX_DATA_PIN );
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/* Setup clock for required baud. */
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UD0CTL1 = serCLOCK_Fxx_DIV_8;
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UD0CTL2 = ulFuclk / ( 2 * ulWantedBaud );
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/* Enable, n81. */
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UD0CTL0 = ( serUPWR | serUTXE | serURXE | serUCL | serLSB );
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/* Enable interrupts for both Rx and Tx. */
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UD0TIC = 0x07;
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UD0RIC = 0x07;
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ulTxInProgress = pdFALSE;
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}
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portEXIT_CRITICAL();
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}
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else
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{
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xReturn = ( xComPortHandle ) 0;
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}
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/* This demo file only supports a single port but we have to return
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something to comply with the standard demo header file. */
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return xReturn;
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}
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/*-----------------------------------------------------------*/
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signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed portCHAR *pcRxedChar, portTickType xBlockTime )
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{
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/* The port handle is not required as this driver only supports one port. */
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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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void vSerialPutString( xComPortHandle pxPort, const signed portCHAR * const pcString, unsigned portSHORT usStringLength )
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{
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signed portCHAR *pxNext;
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/* A couple of parameters that this port does not use. */
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( void ) usStringLength;
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( void ) pxPort;
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/* NOTE: This implementation does not handle the queue being full as no
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block time is used! */
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/* The port handle is not required as this driver only supports UART0. */
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( void ) pxPort;
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/* Send each character in the string, one at a time. */
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pxNext = ( signed portCHAR * ) pcString;
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while( *pxNext )
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{
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xSerialPutChar( pxPort, *pxNext, serNO_BLOCK );
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pxNext++;
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}
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}
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/*-----------------------------------------------------------*/
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signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed portCHAR cOutChar, portTickType xBlockTime )
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{
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portBASE_TYPE xReturn = pdPASS;
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portENTER_CRITICAL();
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{
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/* There are currently no characters queued up to send so write the
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character directly to the UART. */
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if( ulTxInProgress == pdFALSE )
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{
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UD0TX = cOutChar;
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ulTxInProgress = pdTRUE;
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}
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else
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{
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/* The UART is already busy so write the character to the Tx queue.
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The queue is drained from within the Tx interrupt. */
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if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
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{
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xReturn = pdFAIL;
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}
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}
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}
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portEXIT_CRITICAL();
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return xReturn;
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}
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/*-----------------------------------------------------------*/
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void vSerialClose( xComPortHandle xPort )
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{
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/* Not supported as not required by the demo application. */
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}
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/*-----------------------------------------------------------*/
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/* Tx interrupt handler. This is called from the asm file wrapper. */
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void vUARTTxISRHandler( void )
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{
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char cChar;
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portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
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/* Are there any more characters queue to transmit? */
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if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )
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{
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/* Send the next character. */
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UD0TX = cChar;
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}
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else
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{
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/* The UART is no longer active. */
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ulTxInProgress = pdFALSE;
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}
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/* If reading a character from the Rx queue caused a task to unblock, and
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the unblocked task has a priority higher than the currently running task,
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then xHigherPriorityTaskWoken will have been set to true and a context
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switch should occur now. */
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portYIELD_FROM_ISR( xHigherPriorityTaskWoken );
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}
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/*-----------------------------------------------------------*/
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/* Rx interrupt handler. This is called from the asm file wrapper. */
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void vUARTRxISRHandler( void )
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{
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portCHAR cChar;
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portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
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/* Send the received character to the Rx queue. */
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cChar = UD0RX;
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xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
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/* If sending a character to the Tx queue caused a task to unblock, and
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the unblocked task has a priority higher than the currently running task,
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then xHigherPriorityTaskWoken will have been set to true and a context
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switch should occur now. */
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portYIELD_FROM_ISR( xHigherPriorityTaskWoken );
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}
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