2 FreeRTOS V8.2.0rc1 - Copyright (C) 2014 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 >>! NOTE: The modification to the GPL is included to allow you to !<<
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14 >>! distribute a combined work that includes FreeRTOS without being !<<
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15 >>! obliged to provide the source code for proprietary components !<<
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16 >>! outside of the FreeRTOS kernel. !<<
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18 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
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19 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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20 FOR A PARTICULAR PURPOSE. Full license text is available on the following
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21 link: http://www.freertos.org/a00114.html
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25 ***************************************************************************
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27 * Having a problem? Start by reading the FAQ "My application does *
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28 * not run, what could be wrong?". Have you defined configASSERT()? *
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30 * http://www.FreeRTOS.org/FAQHelp.html *
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32 ***************************************************************************
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34 ***************************************************************************
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36 * FreeRTOS provides completely free yet professionally developed, *
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37 * robust, strictly quality controlled, supported, and cross *
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38 * platform software that is more than just the market leader, it *
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39 * is the industry's de facto standard. *
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41 * Help yourself get started quickly while simultaneously helping *
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42 * to support the FreeRTOS project by purchasing a FreeRTOS *
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43 * tutorial book, reference manual, or both: *
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44 * http://www.FreeRTOS.org/Documentation *
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46 ***************************************************************************
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48 ***************************************************************************
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50 * Investing in training allows your team to be as productive as *
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51 * possible as early as possible, lowering your overall development *
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52 * cost, and enabling you to bring a more robust product to market *
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53 * earlier than would otherwise be possible. Richard Barry is both *
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54 * the architect and key author of FreeRTOS, and so also the world's *
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55 * leading authority on what is the world's most popular real time *
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56 * kernel for deeply embedded MCU designs. Obtaining your training *
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57 * from Richard ensures your team will gain directly from his in-depth *
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58 * product knowledge and years of usage experience. Contact Real Time *
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59 * Engineers Ltd to enquire about the FreeRTOS Masterclass, presented *
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60 * by Richard Barry: http://www.FreeRTOS.org/contact
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62 ***************************************************************************
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64 ***************************************************************************
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66 * You are receiving this top quality software for free. Please play *
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67 * fair and reciprocate by reporting any suspected issues and *
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68 * participating in the community forum: *
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69 * http://www.FreeRTOS.org/support *
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73 ***************************************************************************
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75 http://www.FreeRTOS.org - Documentation, books, training, latest versions,
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76 license and Real Time Engineers Ltd. contact details.
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78 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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79 including FreeRTOS+Trace - an indispensable productivity tool, a DOS
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80 compatible FAT file system, and our tiny thread aware UDP/IP stack.
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82 http://www.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate.
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83 Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS.
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85 http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
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86 Integrity Systems ltd. to sell under the OpenRTOS brand. Low cost OpenRTOS
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87 licenses offer ticketed support, indemnification and commercial middleware.
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89 http://www.SafeRTOS.com - High Integrity Systems also provide a safety
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90 engineered and independently SIL3 certified version for use in safety and
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91 mission critical applications that require provable dependability.
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96 /* BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER.
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98 * This file only supports UART 0
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101 /* Standard includes. */
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102 #include <stdlib.h>
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104 /* Scheduler includes. */
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105 #include "FreeRTOS.h"
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109 /* Demo application includes. */
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110 #include "serial.h"
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112 /* The queue used to hold received characters. */
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113 static QueueHandle_t xRxedChars;
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115 /* The queue used to hold characters waiting transmission. */
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116 static QueueHandle_t xCharsForTx;
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118 static volatile short sTHREEmpty;
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120 static volatile short queueFail = pdFALSE;
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122 /*-----------------------------------------------------------*/
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123 xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
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125 /* Initialise the hardware. */
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126 portENTER_CRITICAL();
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128 /* Create the queues used by the com test task. */
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129 xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof(signed char) );
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130 xCharsForTx = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof(signed char) );
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132 if( xRxedChars == 0 )
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134 queueFail = pdTRUE;
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137 if( xCharsForTx == 0 )
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139 queueFail = pdTRUE;
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142 /* Initialize UART asynchronous mode */
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143 BGR0 = configCLKP1_CLOCK_HZ / ulWantedBaud;
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145 SCR0 = 0x17; /* 8N1 */
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146 SMR0 = 0x0d; /* enable SOT3, Reset, normal mode */
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147 SSR0 = 0x02; /* LSB first, enable receive interrupts */
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149 PIER08_IE2 = 1; /* enable input */
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150 DDR08_D2 = 0; /* switch P08_2 to input */
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151 DDR08_D3 = 1; /* switch P08_3 to output */
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153 portEXIT_CRITICAL();
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155 /* Unlike other ports, this serial code does not allow for more than one
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156 com port. We therefore don't return a pointer to a port structure and can
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157 instead just return NULL. */
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160 /*-----------------------------------------------------------*/
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162 signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, TickType_t xBlockTime )
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164 /* Get the next character from the buffer. Return false if no characters
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165 are available, or arrive before xBlockTime expires. */
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166 if( xQueueReceive(xRxedChars, pcRxedChar, xBlockTime) )
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175 /*-----------------------------------------------------------*/
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177 signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, TickType_t xBlockTime )
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179 signed portBASE_TYPE xReturn;
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181 /* Transmit a character. */
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182 portENTER_CRITICAL();
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184 if( sTHREEmpty == pdTRUE )
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186 /* If sTHREEmpty is true then the UART Tx ISR has indicated that
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187 there are no characters queued to be transmitted - so we can
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188 write the character directly to the shift Tx register. */
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189 sTHREEmpty = pdFALSE;
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195 /* sTHREEmpty is false, so there are still characters waiting to be
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196 transmitted. We have to queue this character so it gets
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197 transmitted in turn. */
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199 /* Return false if after the block time there is no room on the Tx
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200 queue. It is ok to block inside a critical section as each task
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201 maintains it's own critical section status. */
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202 if( xQueueSend(xCharsForTx, &cOutChar, xBlockTime) == pdTRUE )
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212 if( pdPASS == xReturn )
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214 /* Turn on the Tx interrupt so the ISR will remove the character from the
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215 queue and send it. This does not need to be in a critical section as
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216 if the interrupt has already removed the character the next interrupt
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217 will simply turn off the Tx interrupt again. */
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221 portEXIT_CRITICAL();
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225 /*-----------------------------------------------------------*/
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228 * UART RX interrupt service routine.
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230 __interrupt void UART0_RxISR( void )
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232 volatile signed char cChar;
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233 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
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235 /* Get the character from the UART and post it on the queue of Rxed
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239 xQueueSendFromISR( xRxedChars, ( const void *const ) &cChar, &xHigherPriorityTaskWoken );
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241 if( xHigherPriorityTaskWoken )
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243 /*If the post causes a task to wake force a context switch
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244 as the woken task may have a higher priority than the task we have
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246 portYIELD_FROM_ISR();
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249 /*-----------------------------------------------------------*/
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252 * UART Tx interrupt service routine.
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254 __interrupt void UART0_TxISR( void )
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257 signed portBASE_TYPE xTaskWoken = pdFALSE;
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259 /* The previous character has been transmitted. See if there are any
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260 further characters waiting transmission. */
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261 if( xQueueReceiveFromISR(xCharsForTx, &cChar, &xTaskWoken) == pdTRUE )
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263 /* There was another character queued - transmit it now. */
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268 /* There were no other characters to transmit. */
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269 sTHREEmpty = pdTRUE;
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271 /* Disable transmit interrupts */
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