2 FreeRTOS V7.5.1 - Copyright (C) 2013 Real Time Engineers Ltd.
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4 VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
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6 ***************************************************************************
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8 * FreeRTOS provides completely free yet professionally developed, *
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9 * robust, strictly quality controlled, supported, and cross *
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10 * platform software that has become a de facto standard. *
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12 * Help yourself get started quickly and support the FreeRTOS *
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13 * project by purchasing a FreeRTOS tutorial book, reference *
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14 * manual, or both from: http://www.FreeRTOS.org/Documentation *
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18 ***************************************************************************
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20 This file is part of the FreeRTOS distribution.
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22 FreeRTOS is free software; you can redistribute it and/or modify it under
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23 the terms of the GNU General Public License (version 2) as published by the
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24 Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
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26 >>! NOTE: The modification to the GPL is included to allow you to distribute
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27 >>! a combined work that includes FreeRTOS without being obliged to provide
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28 >>! the source code for proprietary components outside of the FreeRTOS
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31 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
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32 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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33 FOR A PARTICULAR PURPOSE. Full license text is available from the following
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34 link: http://www.freertos.org/a00114.html
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38 ***************************************************************************
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40 * Having a problem? Start by reading the FAQ "My application does *
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41 * not run, what could be wrong?" *
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43 * http://www.FreeRTOS.org/FAQHelp.html *
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45 ***************************************************************************
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47 http://www.FreeRTOS.org - Documentation, books, training, latest versions,
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48 license and Real Time Engineers Ltd. contact details.
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50 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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51 including FreeRTOS+Trace - an indispensable productivity tool, a DOS
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52 compatible FAT file system, and our tiny thread aware UDP/IP stack.
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54 http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
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55 Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
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56 licenses offer ticketed support, indemnification and middleware.
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58 http://www.SafeRTOS.com - High Integrity Systems also provide a safety
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59 engineered and independently SIL3 certified version for use in safety and
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60 mission critical applications that require provable dependability.
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66 BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR UART0.
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68 *NOTE* - This file is designed to test some of the RTOS features - it is
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69 not intended to represent an efficient implementation!
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72 /* Standard includes. */
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75 /* Scheduler includes. */
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76 #include "FreeRTOS.h"
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79 /* Demo application includes. */
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83 /* Hardware specifics. */
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84 #define serRX_DATA_PIN ( 0x01 )
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85 #define serTX_DATA_PIN ( 0x02 )
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86 #define serCLOCK_Fxx_DIV_8 0x03
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87 #define serUPWR ( 0x80 )
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88 #define serUTXE ( 0x40 )
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89 #define serURXE ( 0x20 )
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90 #define serUCL ( 0x02 )
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91 #define serLSB ( 0x10 )
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94 #define serINVALID_QUEUE ( ( xQueueHandle ) 0 )
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95 #define serHANDLE ( ( xComPortHandle ) 1 )
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96 #define serNO_BLOCK ( ( portTickType ) 0 )
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98 /*-----------------------------------------------------------*/
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100 /* Queues used to hold received characters, and characters waiting to be
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102 static xQueueHandle xRxedChars;
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103 static xQueueHandle xCharsForTx;
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105 /*-----------------------------------------------------------*/
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107 /* Interrupt entry point written in the assembler file serialISR.s85. */
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108 extern void vSerialISREntry( void );
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110 /* Flag to indicate whether or not there are characters already queued to send. */
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111 static volatile unsigned long ulTxInProgress = pdFALSE;
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113 /*-----------------------------------------------------------*/
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116 * See the serial2.h header file.
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118 xComPortHandle xSerialPortInitMinimal( unsigned portLONG ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
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120 xComPortHandle xReturn = serHANDLE;
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121 const unsigned portLONG ulFuclk = ( configCPU_CLOCK_HZ / 2 ) / 8UL;
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123 /* Create the queues used to hold Rx and Tx characters. */
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124 xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
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125 xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
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127 /* If the queues were created correctly then setup the serial port
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129 if( ( xRxedChars != serINVALID_QUEUE ) && ( xCharsForTx != serINVALID_QUEUE ) )
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131 portENTER_CRITICAL();
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133 /* Set the UART0 Rx and Tx pins to their alternative function. */
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134 PMC3 |= ( serRX_DATA_PIN | serTX_DATA_PIN );
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135 PM3 &= ~( serTX_DATA_PIN );
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137 /* Setup clock for required baud. */
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138 UD0CTL1 = serCLOCK_Fxx_DIV_8;
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139 UD0CTL2 = ulFuclk / ( 2 * ulWantedBaud );
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141 /* Enable, n81. */
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142 UD0CTL0 = ( serUPWR | serUTXE | serURXE | serUCL | serLSB );
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144 /* Enable interrupts for both Rx and Tx. */
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148 ulTxInProgress = pdFALSE;
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150 portEXIT_CRITICAL();
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154 xReturn = ( xComPortHandle ) 0;
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157 /* This demo file only supports a single port but we have to return
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158 something to comply with the standard demo header file. */
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161 /*-----------------------------------------------------------*/
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163 signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed portCHAR *pcRxedChar, portTickType xBlockTime )
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165 /* The port handle is not required as this driver only supports one port. */
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168 /* Get the next character from the buffer. Return false if no characters
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169 are available, or arrive before xBlockTime expires. */
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170 if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
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179 /*-----------------------------------------------------------*/
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181 void vSerialPutString( xComPortHandle pxPort, const signed portCHAR * const pcString, unsigned portSHORT usStringLength )
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183 signed portCHAR *pxNext;
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185 /* A couple of parameters that this port does not use. */
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186 ( void ) usStringLength;
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189 /* NOTE: This implementation does not handle the queue being full as no
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190 block time is used! */
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192 /* The port handle is not required as this driver only supports UART0. */
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195 /* Send each character in the string, one at a time. */
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196 pxNext = ( signed portCHAR * ) pcString;
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199 xSerialPutChar( pxPort, *pxNext, serNO_BLOCK );
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203 /*-----------------------------------------------------------*/
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205 signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed portCHAR cOutChar, portTickType xBlockTime )
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207 portBASE_TYPE xReturn = pdPASS;
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209 portENTER_CRITICAL();
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211 /* There are currently no characters queued up to send so write the
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212 character directly to the UART. */
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213 if( ulTxInProgress == pdFALSE )
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216 ulTxInProgress = pdTRUE;
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220 /* The UART is already busy so write the character to the Tx queue.
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221 The queue is drained from within the Tx interrupt. */
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222 if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
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228 portEXIT_CRITICAL();
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232 /*-----------------------------------------------------------*/
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234 void vSerialClose( xComPortHandle xPort )
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236 /* Not supported as not required by the demo application. */
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238 /*-----------------------------------------------------------*/
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240 /* Tx interrupt handler. This is called from the asm file wrapper. */
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241 void vUARTTxISRHandler( void )
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244 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
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246 /* Are there any more characters queue to transmit? */
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247 if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )
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249 /* Send the next character. */
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254 /* The UART is no longer active. */
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255 ulTxInProgress = pdFALSE;
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258 /* If reading a character from the Rx queue caused a task to unblock, and
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259 the unblocked task has a priority higher than the currently running task,
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260 then xHigherPriorityTaskWoken will have been set to true and a context
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261 switch should occur now. */
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262 portYIELD_FROM_ISR( xHigherPriorityTaskWoken );
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264 /*-----------------------------------------------------------*/
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266 /* Rx interrupt handler. This is called from the asm file wrapper. */
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267 void vUARTRxISRHandler( void )
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270 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
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272 /* Send the received character to the Rx queue. */
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274 xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
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276 /* If sending a character to the Tx queue caused a task to unblock, and
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277 the unblocked task has a priority higher than the currently running task,
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278 then xHigherPriorityTaskWoken will have been set to true and a context
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279 switch should occur now. */
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280 portYIELD_FROM_ISR( xHigherPriorityTaskWoken );
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