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 example uses queues to send each character into an interrupt
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69 service routine and out of an interrupt service routine individually. This
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70 is done to demonstrate queues being used in an interrupt, and to deliberately
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71 load the system to test the FreeRTOS port. It is *NOT* meant to be an
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72 example of an efficient implementation. An efficient implementation should
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73 use FIFOs or DMA if available, and only use FreeRTOS API functions when
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74 enough has been received to warrant a task being unblocked to process the
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78 /* Scheduler includes. */
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79 #include "FreeRTOS.h"
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82 #include "comtest2.h"
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84 /* Library includes. */
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85 #include "mb9bf506n.h"
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86 #include "system_mb9bf50x.h"
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88 /* Demo application includes. */
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90 /*-----------------------------------------------------------*/
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92 /* Register bit definitions. */
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93 #define serRX_INT_ENABLE 0x10
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94 #define serTX_INT_ENABLE 0x08
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95 #define serRX_ENABLE 0x02
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96 #define serTX_ENABLE 0x01
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97 #define serORE_ERROR_BIT 0x08
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98 #define serFRE_ERROR_BIT 0x10
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99 #define serPE_ERROR_BIT 0x20
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100 #define serRX_INT 0x04
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101 #define serTX_INT 0x02
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103 /* Misc defines. */
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104 #define serINVALID_QUEUE ( ( xQueueHandle ) 0 )
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105 #define serNO_BLOCK ( ( portTickType ) 0 )
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107 /*-----------------------------------------------------------*/
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109 /* The queue used to hold received characters. */
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110 static xQueueHandle xRxedChars;
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111 static xQueueHandle xCharsForTx;
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113 /*-----------------------------------------------------------*/
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116 * See the serial2.h header file.
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118 xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
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120 /* Create the queues used to hold Rx/Tx characters. */
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121 xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
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122 xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
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124 /* If the queues were created correctly then setup the serial port
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126 if( ( xRxedChars != serINVALID_QUEUE ) && ( xCharsForTx != serINVALID_QUEUE ) )
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128 /* Ensure interrupts don't fire during the init process. Interrupts
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129 will be enabled automatically when the first task start running. */
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130 portDISABLE_INTERRUPTS();
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132 /* Configure P21 and P22 for use by the UART. */
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133 FM3_GPIO->PFR2 |= ( 1 << 0x01 ) | ( 1 << 0x02 );
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135 /* SIN0_0 and SOT0_0. */
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136 FM3_GPIO->EPFR07 |= ( 1 << 6 );
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139 FM3_MFS0_UART->SCR = 0x80;
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141 /* Enable output in mode 0. */
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142 FM3_MFS0_UART->SMR = 0x01;
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144 /* Clear all errors that may already be present. */
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145 FM3_MFS0_UART->SSR = 0x00;
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146 FM3_MFS0_UART->ESCR = 0x00;
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148 FM3_MFS0_UART->BGR = ( configCPU_CLOCK_HZ / 2UL ) / ( ulWantedBaud - 1UL );
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150 /* Enable Rx, Tx, and the Rx interrupt. */
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151 FM3_MFS0_UART->SCR |= ( serRX_ENABLE | serTX_ENABLE | serRX_INT_ENABLE );
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153 /* Configure the NVIC for UART interrupts. */
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154 NVIC_ClearPendingIRQ( MFS0RX_IRQn );
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155 NVIC_EnableIRQ( MFS0RX_IRQn );
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157 /* The priority *MUST* be at or below
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158 configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY as FreeRTOS API functions
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159 are called in the interrupt handler. */
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160 NVIC_SetPriority( MFS0RX_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY );
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162 /* Do the same for the Tx interrupts. */
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163 NVIC_ClearPendingIRQ( MFS0TX_IRQn );
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164 NVIC_EnableIRQ( MFS0TX_IRQn );
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166 /* The priority *MUST* be at or below
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167 configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY as FreeRTOS API functions
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168 are called in the interrupt handler. */
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169 NVIC_SetPriority( MFS0TX_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY );
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172 /* This demo file only supports a single port but we have to return
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173 something to comply with the standard demo header file. */
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174 return ( xComPortHandle ) 0;
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176 /*-----------------------------------------------------------*/
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178 signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, portTickType xBlockTime )
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180 /* The port handle is not required as this driver only supports one port. */
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183 /* Get the next character from the buffer. Return false if no characters
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184 are available, or arrive before xBlockTime expires. */
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185 if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
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194 /*-----------------------------------------------------------*/
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196 void vSerialPutString( xComPortHandle pxPort, const signed char * const pcString, unsigned short usStringLength )
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198 signed char *pxNext;
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200 /* A couple of parameters that this port does not use. */
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201 ( void ) usStringLength;
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204 /* NOTE: This implementation does not handle the queue being full as no
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205 block time is used! */
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207 /* The port handle is not required as this driver only supports one UART. */
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210 /* Send each character in the string, one at a time. */
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211 pxNext = ( signed char * ) pcString;
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214 xSerialPutChar( pxPort, *pxNext, serNO_BLOCK );
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218 /*-----------------------------------------------------------*/
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220 signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, portTickType xBlockTime )
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222 signed portBASE_TYPE xReturn;
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224 if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) == pdPASS )
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228 /* Enable the UART Tx interrupt. */
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229 FM3_MFS0_UART->SCR |= serTX_INT_ENABLE;
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238 /*-----------------------------------------------------------*/
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240 void vSerialClose( xComPortHandle xPort )
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242 /* Not supported as not required by the demo application. */
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244 /*-----------------------------------------------------------*/
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246 void MFS0RX_IRQHandler( void )
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248 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
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251 if( ( FM3_MFS0_UART->SSR & ( serORE_ERROR_BIT | serFRE_ERROR_BIT | serPE_ERROR_BIT ) ) != 0 )
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253 /* A PE, ORE or FRE error occurred. Clear it. */
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254 FM3_MFS0_UART->SSR |= ( 1 << 7 );
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255 cChar = FM3_MFS0_UART->RDR;
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257 else if( FM3_MFS0_UART->SSR & serRX_INT )
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259 /* A character has been received on the USART, send it to the Rx
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261 cChar = FM3_MFS0_UART->RDR;
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262 xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
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265 /* If sending or receiving from a queue has caused a task to unblock, and
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266 the unblocked task has a priority equal to or higher than the currently
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267 running task (the task this ISR interrupted), then xHigherPriorityTaskWoken
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268 will have automatically been set to pdTRUE within the queue send or receive
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269 function. portEND_SWITCHING_ISR() will then ensure that this ISR returns
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270 directly to the higher priority unblocked task. */
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271 portEND_SWITCHING_ISR( xHigherPriorityTaskWoken );
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273 /*-----------------------------------------------------------*/
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275 void MFS0TX_IRQHandler( void )
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277 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
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280 if( FM3_MFS0_UART->SSR & serTX_INT )
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282 /* The interrupt was caused by the TX register becoming empty. Are
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283 there any more characters to transmit? */
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284 if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )
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286 /* A character was retrieved from the queue so can be sent to the
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288 FM3_MFS0_UART->TDR = cChar;
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292 /* Disable the Tx interrupt. */
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293 FM3_MFS0_UART->SCR &= ~serTX_INT_ENABLE;
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297 /* If sending or receiving from a queue has caused a task to unblock, and
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298 the unblocked task has a priority equal to or higher than the currently
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299 running task (the task this ISR interrupted), then xHigherPriorityTaskWoken
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300 will have automatically been set to pdTRUE within the queue send or receive
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301 function. portEND_SWITCHING_ISR() will then ensure that this ISR returns
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302 directly to the higher priority unblocked task. */
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303 portEND_SWITCHING_ISR( xHigherPriorityTaskWoken );
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