2 FreeRTOS V8.0.0 - 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 ***************************************************************************
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9 * FreeRTOS provides completely free yet professionally developed, *
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10 * robust, strictly quality controlled, supported, and cross *
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11 * platform software that has become a de facto standard. *
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13 * Help yourself get started quickly and support the FreeRTOS *
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14 * project by purchasing a FreeRTOS tutorial book, reference *
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15 * manual, or both from: http://www.FreeRTOS.org/Documentation *
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19 ***************************************************************************
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21 This file is part of the FreeRTOS distribution.
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23 FreeRTOS is free software; you can redistribute it and/or modify it under
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24 the terms of the GNU General Public License (version 2) as published by the
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25 Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
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27 >>! NOTE: The modification to the GPL is included to allow you to distribute
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28 >>! a combined work that includes FreeRTOS without being obliged to provide
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29 >>! the source code for proprietary components outside of the FreeRTOS
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32 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
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33 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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34 FOR A PARTICULAR PURPOSE. Full license text is available from the following
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35 link: http://www.freertos.org/a00114.html
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39 ***************************************************************************
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41 * Having a problem? Start by reading the FAQ "My application does *
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42 * not run, what could be wrong?" *
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44 * http://www.FreeRTOS.org/FAQHelp.html *
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46 ***************************************************************************
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48 http://www.FreeRTOS.org - Documentation, books, training, latest versions,
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49 license and Real Time Engineers Ltd. contact details.
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51 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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52 including FreeRTOS+Trace - an indispensable productivity tool, a DOS
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53 compatible FAT file system, and our tiny thread aware UDP/IP stack.
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55 http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
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56 Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
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57 licenses offer ticketed support, indemnification and middleware.
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59 http://www.SafeRTOS.com - High Integrity Systems also provide a safety
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60 engineered and independently SIL3 certified version for use in safety and
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61 mission critical applications that require provable dependability.
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67 BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR UART0.
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70 /* Library 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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82 #define UART0_Rx_Pin ( 0x0001<< 8 )
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83 #define UART0_Tx_Pin ( 0x0001<< 9 )
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85 #define serINVALID_QUEUE ( ( QueueHandle_t ) 0 )
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86 #define serNO_BLOCK ( ( TickType_t ) 0 )
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88 /* Macros to turn on and off the Tx empty interrupt. */
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89 #define serINTERRUPT_ON() UART0->IER |= UART_TxHalfEmpty
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90 #define serINTERRUPT_OFF() UART0->IER &= ~UART_TxHalfEmpty
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92 /*-----------------------------------------------------------*/
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94 /* Queues used to hold received characters, and characters waiting to be
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96 static QueueHandle_t xRxedChars;
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97 static QueueHandle_t xCharsForTx;
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99 /*-----------------------------------------------------------*/
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101 /* Interrupt entry point written in the assembler file serialISR.s79. */
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102 extern void vSerialISREntry( void );
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104 /* The interrupt service routine - called from the assembly entry point. */
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105 __arm void vSerialISR( void );
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107 /*-----------------------------------------------------------*/
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110 * See the serial2.h header file.
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112 xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
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114 xComPortHandle xReturn;
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116 /* Create the queues used to hold Rx and Tx characters. */
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117 xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
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118 xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
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120 /* If the queues were created correctly then setup the serial port
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122 if( ( xRxedChars != serINVALID_QUEUE ) && ( xCharsForTx != serINVALID_QUEUE ) )
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124 portENTER_CRITICAL();
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126 /* Setup the UART port pins. */
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127 GPIO_Config( GPIO0, UART0_Tx_Pin, GPIO_AF_PP );
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128 GPIO_Config( GPIO0, UART0_Rx_Pin, GPIO_IN_TRI_CMOS );
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130 /* Configure the UART. */
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131 UART_OnOffConfig( UART0, ENABLE );
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132 UART_FifoConfig( UART0, DISABLE );
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133 UART_FifoReset( UART0, UART_RxFIFO );
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134 UART_FifoReset( UART0, UART_TxFIFO );
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135 UART_LoopBackConfig(UART0, DISABLE );
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136 UART_Config( UART0, ulWantedBaud, UART_NO_PARITY, UART_1_StopBits, UARTM_8D );
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137 UART_RxConfig( UART0, ENABLE );
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139 /* Configure the IEC for the UART interrupts. */
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140 EIC_IRQChannelPriorityConfig( UART0_IRQChannel, 1 );
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141 EIC_IRQChannelConfig( UART0_IRQChannel, ENABLE );
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142 EIC_IRQConfig( ENABLE );
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143 UART_ItConfig( UART0, UART_RxBufFull, ENABLE );
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145 portEXIT_CRITICAL();
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149 xReturn = ( xComPortHandle ) 0;
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152 /* This demo file only supports a single port but we have to return
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153 something to comply with the standard demo header file. */
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156 /*-----------------------------------------------------------*/
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158 signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, TickType_t xBlockTime )
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160 /* The port handle is not required as this driver only supports one port. */
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163 /* Get the next character from the buffer. Return false if no characters
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164 are available, or arrive before xBlockTime expires. */
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165 if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
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174 /*-----------------------------------------------------------*/
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176 void vSerialPutString( xComPortHandle pxPort, const signed char * const pcString, unsigned short usStringLength )
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178 signed char *pxNext;
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180 /* A couple of parameters that this port does not use. */
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181 ( void ) usStringLength;
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184 /* NOTE: This implementation does not handle the queue being full as no
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185 block time is used! */
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187 /* The port handle is not required as this driver only supports UART0. */
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190 /* Send each character in the string, one at a time. */
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191 pxNext = ( signed char * ) pcString;
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194 xSerialPutChar( pxPort, *pxNext, serNO_BLOCK );
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198 /*-----------------------------------------------------------*/
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200 signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, TickType_t xBlockTime )
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202 /* Place the character in the queue of characters to be transmitted. */
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203 if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
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208 /* Turn on the Tx interrupt so the ISR will remove the character from the
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209 queue and send it. This does not need to be in a critical section as
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210 if the interrupt has already removed the character the next interrupt
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211 will simply turn off the Tx interrupt again. */
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216 /*-----------------------------------------------------------*/
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218 void vSerialClose( xComPortHandle xPort )
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220 /* Not supported as not required by the demo application. */
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222 /*-----------------------------------------------------------*/
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224 /* Serial port ISR. This can cause a context switch so is not defined as a
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225 standard ISR using the __irq keyword. Instead a wrapper function is defined
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226 within serialISR.s79 which in turn calls this function. See the port
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227 documentation on the FreeRTOS.org website for more information. */
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228 __arm void vSerialISR( void )
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230 unsigned short usStatus;
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232 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
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234 /* What caused the interrupt? */
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235 usStatus = UART_FlagStatus( UART0 );
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237 if( usStatus & UART_TxHalfEmpty )
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239 /* The interrupt was caused by the THR becoming empty. Are there any
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240 more characters to transmit? */
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241 if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )
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243 /* A character was retrieved from the queue so can be sent to the
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245 UART0->TxBUFR = cChar;
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249 /* Queue empty, nothing to send so turn off the Tx interrupt. */
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250 serINTERRUPT_OFF();
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254 if( usStatus & UART_RxBufFull )
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256 /* The interrupt was caused by a character being received. Grab the
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257 character from the RHR and place it in the queue of received
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259 cChar = UART0->RxBUFR;
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260 xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
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263 /* If a task was woken by either a character being received or a character
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264 being transmitted then we may need to switch to another task. */
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265 portEND_SWITCHING_ISR( xHigherPriorityTaskWoken );
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267 /* End the interrupt in the EIC. */
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