2 FreeRTOS.org V4.7.0 - Copyright (C) 2003-2007 Richard Barry.
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4 This file is part of the FreeRTOS.org distribution.
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6 FreeRTOS.org is free software; you can redistribute it and/or modify
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7 it under the terms of the GNU General Public License as published by
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8 the Free Software Foundation; either version 2 of the License, or
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9 (at your option) any later version.
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11 FreeRTOS.org is distributed in the hope that it will be useful,
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12 but WITHOUT ANY WARRANTY; without even the implied warranty of
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13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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14 GNU General Public License for more details.
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16 You should have received a copy of the GNU General Public License
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17 along with FreeRTOS.org; if not, write to the Free Software
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18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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20 A special exception to the GPL can be applied should you wish to distribute
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21 a combined work that includes FreeRTOS.org, without being obliged to provide
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22 the source code for any proprietary components. See the licensing section
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23 of http://www.FreeRTOS.org for full details of how and when the exception
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26 ***************************************************************************
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27 See http://www.FreeRTOS.org for documentation, latest information, license
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28 and contact details. Please ensure to read the configuration and relevant
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29 port sections of the online documentation.
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31 Also see http://www.SafeRTOS.com a version that has been certified for use
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32 in safety critical systems, plus commercial licensing, development and
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34 ***************************************************************************
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38 /* BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER.
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40 * This file only supports UART 2
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43 /* Standard includes. */
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46 /* Scheduler includes. */
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47 #include "FreeRTOS.h"
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51 /* Demo application includes. */
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54 /* The queue used to hold received characters. */
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55 static xQueueHandle xRxedChars;
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57 /* The queue used to hold characters waiting transmission. */
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58 static xQueueHandle xCharsForTx;
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60 static volatile portSHORT sTHREEmpty;
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62 /*-----------------------------------------------------------*/
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64 xComPortHandle xSerialPortInitMinimal( unsigned portLONG ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
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66 //unsigned portLONG ulBaudRateCount;
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68 portENTER_CRITICAL();
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70 /* Create the queues used by the com test task. */
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71 xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
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72 xCharsForTx = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
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74 /* Initialize UART asynchronous mode */
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75 BGR02 = configPER_CLOCK_HZ / ulWantedBaud;
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77 SCR02 = 0x17; /* 8N1 */
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78 SMR02 = 0x0d; /* enable SOT3, Reset, normal mode */
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79 SSR02 = 0x02; /* LSB first, enable receive interrupts */
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81 PFR20_D0 = 1; // enable UART
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82 PFR20_D1 = 1; // enable UART
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84 EPFR20_D1 = 0; // enable UART
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86 portEXIT_CRITICAL();
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88 /* Unlike other ports, this serial code does not allow for more than one
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89 com port. We therefore don't return a pointer to a port structure and can
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90 instead just return NULL. */
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93 /*-----------------------------------------------------------*/
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95 signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed portCHAR *pcRxedChar, portTickType xBlockTime )
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97 /* Get the next character from the buffer. Return false if no characters
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98 are available, or arrive before xBlockTime expires. */
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99 if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
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108 /*-----------------------------------------------------------*/
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110 signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed portCHAR cOutChar, portTickType xBlockTime )
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112 signed portBASE_TYPE xReturn;
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114 /* Transmit a character. */
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115 portENTER_CRITICAL();
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117 if( sTHREEmpty == pdTRUE )
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119 /* If sTHREEmpty is true then the UART Tx ISR has indicated that
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120 there are no characters queued to be transmitted - so we can
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121 write the character directly to the shift Tx register. */
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122 sTHREEmpty = pdFALSE;
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128 /* sTHREEmpty is false, so there are still characters waiting to be
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129 transmitted. We have to queue this character so it gets
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130 transmitted in turn. */
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132 /* Return false if after the block time there is no room on the Tx
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133 queue. It is ok to block inside a critical section as each task
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134 maintains it's own critical section status. */
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135 if (xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) == pdTRUE)
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145 if (pdPASS == xReturn)
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147 /* Turn on the Tx interrupt so the ISR will remove the character from the
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148 queue and send it. This does not need to be in a critical section as
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149 if the interrupt has already removed the character the next interrupt
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150 will simply turn off the Tx interrupt again. */
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155 portEXIT_CRITICAL();
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159 /*-----------------------------------------------------------*/
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162 * UART RX interrupt service routine.
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164 __interrupt void UART2_RxISR (void)
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166 signed portCHAR cChar;
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168 /* Get the character from the UART and post it on the queue of Rxed
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172 if( xQueueSendFromISR( xRxedChars, &cChar, pdFALSE ) )
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174 /*If the post causes a task to wake force a context switch
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175 as the woken task may have a higher priority than the task we have
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177 portYIELD_FROM_ISR();
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181 /*-----------------------------------------------------------*/
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184 * UART Tx interrupt service routine.
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186 __interrupt void UART2_TxISR (void)
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188 signed portCHAR cChar;
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189 signed portBASE_TYPE xTaskWoken;
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191 /* The previous character has been transmitted. See if there are any
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192 further characters waiting transmission. */
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193 if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xTaskWoken ) == pdTRUE )
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195 /* There was another character queued - transmit it now. */
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200 /* There were no other characters to transmit. */
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201 sTHREEmpty = pdTRUE;
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203 /* Disable transmit interrupts */
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