2 FreeRTOS V7.4.2 - Copyright (C) 2013 Real Time Engineers Ltd.
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4 FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME. PLEASE VISIT
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5 http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
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7 ***************************************************************************
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9 * FreeRTOS tutorial books are available in pdf and paperback. *
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10 * Complete, revised, and edited pdf reference manuals are also *
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13 * Purchasing FreeRTOS documentation will not only help you, by *
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14 * ensuring you get running as quickly as possible and with an *
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15 * in-depth knowledge of how to use FreeRTOS, it will also help *
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16 * the FreeRTOS project to continue with its mission of providing *
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17 * professional grade, cross platform, de facto standard solutions *
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18 * for microcontrollers - completely free of charge! *
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20 * >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
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22 * Thank you for using FreeRTOS, and thank you for your support! *
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24 ***************************************************************************
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27 This file is part of the FreeRTOS distribution.
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29 FreeRTOS is free software; you can redistribute it and/or modify it under
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30 the terms of the GNU General Public License (version 2) as published by the
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31 Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
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33 >>>>>>NOTE<<<<<< The modification to the GPL is included to allow you to
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34 distribute a combined work that includes FreeRTOS without being obliged to
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35 provide the source code for proprietary components outside of the FreeRTOS
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38 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
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39 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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40 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
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41 details. You should have received a copy of the GNU General Public License
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42 and the FreeRTOS license exception along with FreeRTOS; if not it can be
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43 viewed here: http://www.freertos.org/a00114.html and also obtained by
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44 writing to Real Time Engineers Ltd., contact details for whom are available
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45 on the FreeRTOS WEB site.
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49 ***************************************************************************
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51 * Having a problem? Start by reading the FAQ "My application does *
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52 * not run, what could be wrong?" *
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54 * http://www.FreeRTOS.org/FAQHelp.html *
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56 ***************************************************************************
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59 http://www.FreeRTOS.org - Documentation, books, training, latest versions,
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60 license and Real Time Engineers Ltd. contact details.
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62 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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63 including FreeRTOS+Trace - an indispensable productivity tool, and our new
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64 fully thread aware and reentrant UDP/IP stack.
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66 http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
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67 Integrity Systems, who sell the code with commercial support,
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68 indemnification and middleware, under the OpenRTOS brand.
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70 http://www.SafeRTOS.com - High Integrity Systems also provide a safety
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71 engineered and independently SIL3 certified version for use in safety and
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72 mission critical applications that require provable dependability.
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77 BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR UART
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80 /* Scheduler includes. */
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81 #include "FreeRTOS.h"
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85 /* Demo application includes. */
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88 /* Library includes. */
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89 #include "xparameters.h"
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90 #include "xuartlite.h"
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91 #include "xuartlite_l.h"
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93 /*-----------------------------------------------------------*/
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95 /* Queues used to hold received characters, and characters waiting to be
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97 static xQueueHandle xRxedChars;
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98 static xQueueHandle xCharsForTx;
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100 /* Structure that maintains information on the UART being used. */
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101 static XUartLite xUART;
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104 * Sample UART interrupt handler. Note this is used to demonstrate the kernel
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105 * features and test the port - it is not intended to represent an efficient
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108 static void vSerialISR( XUartLite *pxUART );
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110 /*-----------------------------------------------------------*/
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112 xComPortHandle xSerialPortInitMinimal( unsigned portLONG ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
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114 /* NOTE: The baud rate used by this driver is determined by the hardware
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115 parameterization of the UART Lite peripheral, and the baud value passed to
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116 this function has no effect. */
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117 ( void ) ulWantedBaud;
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119 /* Create the queues used to hold Rx and Tx characters. */
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120 xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
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121 xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
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123 /* Only initialise the UART if the queues were created correctly. */
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124 if( ( xRxedChars != NULL ) && ( xCharsForTx != NULL ) )
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127 XUartLite_Initialize( &xUART, XPAR_RS232_UART_DEVICE_ID );
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128 XUartLite_ResetFifos( &xUART );
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129 XUartLite_DisableInterrupt( &xUART );
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131 if( xPortInstallInterruptHandler( XPAR_XPS_INTC_0_RS232_UART_INTERRUPT_INTR, ( XInterruptHandler )vSerialISR, (void *)&xUART ) == pdPASS )
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133 /* xPortInstallInterruptHandler() could fail if
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134 vPortSetupInterruptController() has not been called prior to this
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136 XUartLite_EnableInterrupt( &xUART );
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140 /* There is only one port so the handle is not used. */
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141 return ( xComPortHandle ) 0;
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143 /*-----------------------------------------------------------*/
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145 signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed portCHAR *pcRxedChar, portTickType xBlockTime )
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147 /* The port handle is not required as this driver only supports one UART. */
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150 /* Get the next character from the buffer. Return false if no characters
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151 are available, or arrive before xBlockTime expires. */
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152 if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
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161 /*-----------------------------------------------------------*/
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163 signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed portCHAR cOutChar, portTickType xBlockTime )
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165 portBASE_TYPE xReturn = pdTRUE;
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167 /* Just to remove compiler warning. */
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170 portENTER_CRITICAL();
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172 /* If the UART FIFO is full we can block posting the new data on the
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174 if( XUartLite_mIsTransmitFull( XPAR_RS232_UART_BASEADDR ) )
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176 if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
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181 /* Otherwise, if there is data already in the queue we should add the
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182 new data to the back of the queue to ensure the sequencing is
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184 else if( uxQueueMessagesWaiting( xCharsForTx ) )
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186 if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
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191 /* If the UART FIFO is not full and there is no data already in the
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192 queue we can write directly to the FIFO without disrupting the
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196 XIo_Out32( XPAR_RS232_UART_BASEADDR + XUL_TX_FIFO_OFFSET, cOutChar );
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199 portEXIT_CRITICAL();
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203 /*-----------------------------------------------------------*/
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205 void vSerialClose( xComPortHandle xPort )
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207 /* Not supported as not required by the demo application. */
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210 /*-----------------------------------------------------------*/
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212 static void vSerialISR( XUartLite *pxUART )
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214 unsigned portLONG ulISRStatus;
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215 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE, lDidSomething;
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218 /* Just to remove compiler warning. */
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223 lDidSomething = pdFALSE;
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225 ulISRStatus = XIo_In32( XPAR_RS232_UART_BASEADDR + XUL_STATUS_REG_OFFSET );
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227 if( ( ulISRStatus & XUL_SR_RX_FIFO_VALID_DATA ) != 0 )
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229 /* A character is available - place it in the queue of received
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230 characters. This might wake a task that was blocked waiting for
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232 cChar = ( portCHAR ) XIo_In32( XPAR_RS232_UART_BASEADDR + XUL_RX_FIFO_OFFSET );
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233 xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
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234 lDidSomething = pdTRUE;
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237 if( ( ulISRStatus & XUL_SR_TX_FIFO_EMPTY ) != 0 )
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239 /* There is space in the FIFO - if there are any characters queue for
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240 transmission they can be sent to the UART now. This might unblock a
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241 task that was waiting for space to become available on the Tx queue. */
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242 if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )
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244 XIo_Out32( XPAR_RS232_UART_BASEADDR + XUL_TX_FIFO_OFFSET, cChar );
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245 lDidSomething = pdTRUE;
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248 } while( lDidSomething == pdTRUE );
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250 /* If we woke any tasks we may require a context switch. */
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251 if( xHigherPriorityTaskWoken )
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253 portYIELD_FROM_ISR();
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