2 FreeRTOS V8.2.0 - Copyright (C) 2015 Real Time Engineers Ltd.
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5 VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
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7 This file is part of the FreeRTOS distribution.
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9 FreeRTOS is free software; you can redistribute it and/or modify it under
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10 the terms of the GNU General Public License (version 2) as published by the
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11 Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
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13 ***************************************************************************
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14 >>! NOTE: The modification to the GPL is included to allow you to !<<
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15 >>! distribute a combined work that includes FreeRTOS without being !<<
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16 >>! obliged to provide the source code for proprietary components !<<
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17 >>! outside of the FreeRTOS kernel. !<<
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18 ***************************************************************************
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20 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
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21 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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22 FOR A PARTICULAR PURPOSE. Full license text is available on the following
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23 link: http://www.freertos.org/a00114.html
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25 ***************************************************************************
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27 * FreeRTOS provides completely free yet professionally developed, *
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28 * robust, strictly quality controlled, supported, and cross *
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29 * platform software that is more than just the market leader, it *
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30 * is the industry's de facto standard. *
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32 * Help yourself get started quickly while simultaneously helping *
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33 * to support the FreeRTOS project by purchasing a FreeRTOS *
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34 * tutorial book, reference manual, or both: *
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35 * http://www.FreeRTOS.org/Documentation *
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37 ***************************************************************************
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39 http://www.FreeRTOS.org/FAQHelp.html - Having a problem? Start by reading
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40 the FAQ page "My application does not run, what could be wrong?". Have you
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41 defined configASSERT()?
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43 http://www.FreeRTOS.org/support - In return for receiving this top quality
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44 embedded software for free we request you assist our global community by
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45 participating in the support forum.
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47 http://www.FreeRTOS.org/training - Investing in training allows your team to
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48 be as productive as possible as early as possible. Now you can receive
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49 FreeRTOS training directly from Richard Barry, CEO of Real Time Engineers
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50 Ltd, and the world's leading authority on the world's leading RTOS.
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52 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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53 including FreeRTOS+Trace - an indispensable productivity tool, a DOS
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54 compatible FAT file system, and our tiny thread aware UDP/IP stack.
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56 http://www.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate.
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57 Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS.
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59 http://www.OpenRTOS.com - Real Time Engineers ltd. license FreeRTOS to High
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60 Integrity Systems ltd. to sell under the OpenRTOS brand. Low cost OpenRTOS
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61 licenses offer ticketed support, indemnification and commercial middleware.
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63 http://www.SafeRTOS.com - High Integrity Systems also provide a safety
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64 engineered and independently SIL3 certified version for use in safety and
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65 mission critical applications that require provable dependability.
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71 /* BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER.
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73 * This file only supports UART 1
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76 /* Standard includes. */
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79 /* Scheduler includes. */
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80 #include "FreeRTOS.h"
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84 /* Demo application includes. */
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87 /* Constants required to setup the hardware. */
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88 #define serTX_AND_RX ( ( unsigned char ) 0x03 )
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90 /* Misc. constants. */
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91 #define serNO_BLOCK ( ( TickType_t ) 0 )
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93 /* Enable the UART Tx interrupt. */
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94 #define vInterruptOn() IFG2 |= UTXIFG1
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96 /* The queue used to hold received characters. */
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97 static QueueHandle_t xRxedChars;
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99 /* The queue used to hold characters waiting transmission. */
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100 static QueueHandle_t xCharsForTx;
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102 static volatile short sTHREEmpty;
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104 /*-----------------------------------------------------------*/
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106 xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
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108 unsigned long ulBaudRateCount;
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110 /* Initialise the hardware. */
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112 /* Generate the baud rate constants for the wanted baud rate. */
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113 ulBaudRateCount = configCPU_CLOCK_HZ / ulWantedBaud;
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115 portENTER_CRITICAL();
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117 /* Create the queues used by the com test task. */
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118 xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
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119 xCharsForTx = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
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124 /* Set pin function. */
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125 P4SEL |= serTX_AND_RX;
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127 /* All other bits remain at zero for n, 8, 1 interrupt driven operation.
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129 U1CTL |= CHAR + LISTEN;
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132 /* Setup baud rate low byte. */
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133 U1BR0 = ( unsigned char ) ( ulBaudRateCount & ( unsigned long ) 0xff );
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135 /* Setup baud rate high byte. */
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136 ulBaudRateCount >>= 8UL;
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137 U1BR1 = ( unsigned char ) ( ulBaudRateCount & ( unsigned long ) 0xff );
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139 /* Enable ports. */
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140 ME2 |= UTXE1 + URXE1;
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145 /* Nothing in the buffer yet. */
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146 sTHREEmpty = pdTRUE;
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148 /* Enable interrupts. */
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149 IE2 |= URXIE1 + UTXIE1;
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151 portEXIT_CRITICAL();
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153 /* Unlike other ports, this serial code does not allow for more than one
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154 com port. We therefore don't return a pointer to a port structure and can
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155 instead just return NULL. */
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158 /*-----------------------------------------------------------*/
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160 signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, TickType_t xBlockTime )
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162 /* Get the next character from the buffer. Return false if no characters
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163 are available, or arrive before xBlockTime expires. */
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164 if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
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173 /*-----------------------------------------------------------*/
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175 signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, TickType_t xBlockTime )
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177 signed portBASE_TYPE xReturn;
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179 /* Transmit a character. */
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181 portENTER_CRITICAL();
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183 if( sTHREEmpty == pdTRUE )
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185 /* If sTHREEmpty is true then the UART Tx ISR has indicated that
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186 there are no characters queued to be transmitted - so we can
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187 write the character directly to the shift Tx register. */
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188 sTHREEmpty = pdFALSE;
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189 U1TXBUF = cOutChar;
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194 /* sTHREEmpty is false, so there are still characters waiting to be
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195 transmitted. We have to queue this character so it gets
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196 transmitted in turn. */
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198 /* Return false if after the block time there is no room on the Tx
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199 queue. It is ok to block inside a critical section as each task
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200 maintains it's own critical section status. */
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201 xReturn = xQueueSend( xCharsForTx, &cOutChar, xBlockTime );
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203 /* Depending on queue sizing and task prioritisation: While we
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204 were blocked waiting to post on the queue interrupts were not
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205 disabled. It is possible that the serial ISR has emptied the
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206 Tx queue, in which case we need to start the Tx off again
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207 writing directly to the Tx register. */
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208 if( ( sTHREEmpty == pdTRUE ) && ( xReturn == pdPASS ) )
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210 /* Get back the character we just posted. */
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211 xQueueReceive( xCharsForTx, &cOutChar, serNO_BLOCK );
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212 sTHREEmpty = pdFALSE;
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213 U1TXBUF = cOutChar;
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217 portEXIT_CRITICAL();
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221 /*-----------------------------------------------------------*/
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223 #if configINTERRUPT_EXAMPLE_METHOD == 1
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226 * UART RX interrupt service routine.
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228 #pragma vector=UART1RX_VECTOR
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229 __interrupt void vRxISR( void )
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232 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
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234 /* Get the character from the UART and post it on the queue of Rxed
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238 xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
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240 if( xHigherPriorityTaskWoken )
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242 /*If the post causes a task to wake force a context switch
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243 as the woken task may have a higher priority than the task we have
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248 /* Make sure any low power mode bits are clear before leaving the ISR. */
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249 __bic_SR_register_on_exit( SCG1 + SCG0 + OSCOFF + CPUOFF );
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251 /*-----------------------------------------------------------*/
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254 * UART Tx interrupt service routine.
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256 #pragma vector=UART1TX_VECTOR
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257 __interrupt void vTxISR( void )
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260 portBASE_TYPE xTaskWoken = pdFALSE;
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262 /* The previous character has been transmitted. See if there are any
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263 further characters waiting transmission. */
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265 if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xTaskWoken ) == pdTRUE )
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267 /* There was another character queued - transmit it now. */
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272 /* There were no other characters to transmit. */
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273 sTHREEmpty = pdTRUE;
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276 /* Make sure any low power mode bits are clear before leaving the ISR. */
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277 __bic_SR_register_on_exit( SCG1 + SCG0 + OSCOFF + CPUOFF );
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279 /*-----------------------------------------------------------*/
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281 #elif configINTERRUPT_EXAMPLE_METHOD == 2
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283 /* This is a standard C function as an assembly file wrapper is used as an
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284 interrupt entry point. */
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285 void vRxISR( void )
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288 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
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290 /* Get the character from the UART and post it on the queue of Rxed
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294 xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
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296 /*If the post causes a task to wake force a context switch
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297 as the woken task may have a higher priority than the task we have
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299 portYIELD_FROM_ISR( xHigherPriorityTaskWoken );
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301 /*-----------------------------------------------------------*/
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303 /* This is a standard C function as an assembly file wrapper is used as an
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304 interrupt entry point. */
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305 void vTxISR( void )
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308 portBASE_TYPE xTaskWoken = pdFALSE;
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310 /* The previous character has been transmitted. See if there are any
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311 further characters waiting transmission. */
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313 if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xTaskWoken ) == pdTRUE )
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315 /* There was another character queued - transmit it now. */
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320 /* There were no other characters to transmit. */
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321 sTHREEmpty = pdTRUE;
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325 #endif /* configINTERRUPT_EXAMPLE_METHOD */
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326 /*-----------------------------------------------------------*/
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