2 FreeRTOS.org V5.1.0 - Copyright (C) 2003-2008 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 ***************************************************************************
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29 * SAVE TIME AND MONEY! We can port FreeRTOS.org to your own hardware, *
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30 * and even write all or part of your application on your behalf. *
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31 * See http://www.OpenRTOS.com for details of the services we provide to *
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32 * expedite your project. *
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34 ***************************************************************************
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35 ***************************************************************************
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37 Please ensure to read the configuration and relevant port sections of the
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38 online documentation.
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40 http://www.FreeRTOS.org - Documentation, latest information, license and
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43 http://www.SafeRTOS.com - A version that is certified for use in safety
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46 http://www.OpenRTOS.com - Commercial support, development, porting,
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47 licensing and training services.
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51 * This demo application creates seven co-routines and one task (two including
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52 * the idle task). The co-routines execute as part of the idle task hook.
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54 * Five of the created co-routines are the standard 'co-routine flash'
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55 * co-routines contained within the Demo/Common/Minimal/crflash.c file and
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56 * documented on the FreeRTOS.org WEB site.
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58 * The 'LCD Task' rotates a string on the LCD, delaying between each character
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59 * as necessitated by the slow interface, and delaying between each string just
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60 * long enough to enable the text to be read.
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62 * The sixth co-routine controls the transmission of a string to UART 0. The
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63 * co-routine periodically sends the first character of the string to the UART,
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64 * with the UART's TxEnd interrupt being used to transmit the remaining
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65 * characters. The UART's RxEnd interrupt receives the characters and places
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66 * them on a queue to be processed by the seventh and final co-routine. An
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67 * error is latched should an unexpected character be received, or any
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68 * character be received out of sequence.
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70 * A loopback connector is required to ensure that each character transmitted
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71 * on the UART is also received on the same UART. For test purposes the UART
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72 * FIFO's are not utalised in order to maximise the interrupt overhead. Also
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73 * a pseudo random interval is used between the start of each transmission in
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74 * order that the resultant interrupts are more randomly distributed and
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75 * therefore more likely to highlight any problems.
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77 * The flash co-routines control LED's zero to four. LED five is toggled each
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78 * time the string is transmitted on the UART. LED six is toggled each time
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79 * the string is CORRECTLY received on the UART. LED seven is latched on should
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80 * an error be detected in any task or co-routine.
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82 * In addition the idle task makes repetative calls to
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83 * prvSetAndCheckRegisters(). This simply loads the general purpose registers
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84 * with a known value, then checks each register to ensure the held value is
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85 * still correct. As a low priority task this checking routine is likely to
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86 * get repeatedly swapped in and out. A register being found to contain an
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87 * incorrect value is therefore indicative of an error in the task switching
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92 /* Scheduler include files. */
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93 #include "FreeRTOS.h"
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96 #include "croutine.h"
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98 /* Demo application include files. */
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99 #include "partest.h"
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100 #include "crflash.h"
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102 /* Library include files. */
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103 #include "DriverLib.h"
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105 /* The time to delay between writing each character to the LCD. */
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106 #define mainCHAR_WRITE_DELAY ( 2 / portTICK_RATE_MS )
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108 /* The time to delay between writing each string to the LCD. */
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109 #define mainSTRING_WRITE_DELAY ( 400 / portTICK_RATE_MS )
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111 /* The number of flash co-routines to create. */
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112 #define mainNUM_FLASH_CO_ROUTINES ( 5 )
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114 /* The length of the queue used to pass received characters to the Comms Rx
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116 #define mainRX_QUEUE_LEN ( 5 )
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118 /* The priority of the co-routine used to initiate the transmission of the
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119 string on UART 0. */
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120 #define mainTX_CO_ROUTINE_PRIORITY ( 1 )
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122 /* The priority of the co-routine used to receive characters from the UART. */
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123 #define mainRX_CO_ROUTINE_PRIORITY ( 2 )
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125 /* Only one co-routine is created so its index is not important. */
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126 #define mainTX_CO_ROUTINE_INDEX ( 0 )
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127 #define mainRX_CO_ROUTINE_INDEX ( 0 )
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129 /* The time between transmissions of the string on UART 0. This is pseudo
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130 random in order to generate a bit or randomness to when the interrupts occur.*/
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131 #define mainMIN_TX_DELAY ( 40 / portTICK_RATE_MS )
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132 #define mainMAX_TX_DELAY ( ( portTickType ) 0x7f )
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133 #define mainOFFSET_TIME ( ( portTickType ) 3 )
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135 /* The time the Comms Rx task should wait to receive a character. This should
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136 be slightly longer than the time between transmissions. If we do not receive
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137 a character after this time then there must be an error in the transmission or
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138 the timing of the transmission. */
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139 #define mainCOMMS_RX_DELAY ( mainMAX_TX_DELAY + 20 )
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141 /* The task priorites. */
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142 #define mainLCD_TASK_PRIORITY ( tskIDLE_PRIORITY )
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143 #define mainCOMMS_RX_TASK_PRIORITY ( tskIDLE_PRIORITY + 1 )
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145 /* The LED's toggled by the various tasks. */
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146 #define mainCOMMS_FAIL_LED ( 7 )
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147 #define mainCOMMS_RX_LED ( 6 )
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148 #define mainCOMMS_TX_LED ( 5 )
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150 /* The baud rate used by the UART comms tasks/co-routine. */
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151 #define mainBAUD_RATE ( 57600 )
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153 /* FIFO setting for the UART. The FIFO is not used to create a better test. */
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154 #define mainFIFO_SET ( 0x10 )
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156 /* The string that is transmitted on the UART contains sequentially the
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157 characters from mainFIRST_TX_CHAR to mainLAST_TX_CHAR. */
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158 #define mainFIRST_TX_CHAR '0'
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159 #define mainLAST_TX_CHAR 'z'
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161 /* Just used to walk through the program memory in order that some random data
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162 can be generated. */
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163 #define mainTOTAL_PROGRAM_MEMORY ( ( unsigned portLONG * ) ( 8 * 1024 ) )
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164 #define mainFIRST_PROGRAM_BYTES ( ( unsigned portLONG * ) 4 )
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166 /* The error routine that is called if the driver library encounters an error. */
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169 __error__(char *pcFilename, unsigned long ulLine)
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174 /*-----------------------------------------------------------*/
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177 * The task that rotates text on the LCD.
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179 static void vLCDTask( void * pvParameters );
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182 * The task that receives the characters from UART 0.
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184 static void vCommsRxCoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex );
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187 * The co-routine that periodically initiates the transmission of the string on
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190 static void vSerialTxCoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex );
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193 * Writes a string the the LCD.
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195 static void prvWriteString( const portCHAR *pcString );
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198 * Initialisation routine for the UART.
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200 static void vSerialInit( void );
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203 * Thread safe write to the PDC.
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205 static void prvPDCWrite( portCHAR cAddress, portCHAR cData );
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208 * Function to simply set a known value into the general purpose registers
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209 * then read them back to ensure they remain set correctly. An incorrect value
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210 * being indicative of an error in the task switching mechanism.
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212 void prvSetAndCheckRegisters( void );
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215 * Latch the LED that indicates that an error has occurred.
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217 void vSetErrorLED( void );
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220 * Sets up the PLL and ports used by the demo.
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222 static void prvSetupHardware( void );
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224 /*-----------------------------------------------------------*/
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226 /* Error flag set to pdFAIL if an error is encountered in the tasks/co-routines
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227 defined within this file. */
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228 unsigned portBASE_TYPE uxErrorStatus = pdPASS;
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230 /* The next character to transmit. */
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231 static portCHAR cNextChar;
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233 /* The queue used to transmit characters from the interrupt to the Comms Rx
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235 static xQueueHandle xCommsQueue;
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237 /*-----------------------------------------------------------*/
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241 /* Create the queue used to communicate between the UART ISR and the Comms
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243 xCommsQueue = xQueueCreate( mainRX_QUEUE_LEN, sizeof( portCHAR ) );
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245 /* Setup the ports used by the demo and the clock. */
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246 prvSetupHardware();
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248 /* Create the co-routines that flash the LED's. */
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249 vStartFlashCoRoutines( mainNUM_FLASH_CO_ROUTINES );
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251 /* Create the co-routine that initiates the transmission of characters
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253 xCoRoutineCreate( vSerialTxCoRoutine, mainTX_CO_ROUTINE_PRIORITY, mainTX_CO_ROUTINE_INDEX );
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255 /* Create the co-routine that receives characters from the UART. */
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256 xCoRoutineCreate( vCommsRxCoRoutine, mainRX_CO_ROUTINE_PRIORITY, mainRX_CO_ROUTINE_INDEX );
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258 /* Create the LCD task. */
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259 xTaskCreate( vLCDTask, "LCD", configMINIMAL_STACK_SIZE, NULL, mainLCD_TASK_PRIORITY, NULL );
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261 /* Start the scheduler running the tasks and co-routines just created. */
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262 vTaskStartScheduler();
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264 /* Should not get here unless we did not have enough memory to start the
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268 /*-----------------------------------------------------------*/
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270 static void prvSetupHardware( void )
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272 /* Setup the PLL. */
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273 SysCtlClockSet( SYSCTL_SYSDIV_10 | SYSCTL_USE_PLL | SYSCTL_OSC_MAIN | SYSCTL_XTAL_6MHZ );
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275 /* Initialise the hardware used to talk to the LCD, LED's and UART. */
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277 vParTestInitialise();
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280 /*-----------------------------------------------------------*/
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282 void vApplicationIdleHook( void )
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284 /* The co-routines are executed in the idle task using the idle task
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288 /* Schedule the co-routines. */
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289 vCoRoutineSchedule();
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291 /* Run the register check function between each co-routine. */
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292 prvSetAndCheckRegisters();
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295 /*-----------------------------------------------------------*/
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297 static void prvWriteString( const portCHAR *pcString )
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299 /* Write pcString to the LED, pausing between each character. */
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300 prvPDCWrite(PDC_LCD_CSR, LCD_CLEAR);
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303 vTaskDelay( mainCHAR_WRITE_DELAY );
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304 prvPDCWrite( PDC_LCD_RAM, *pcString );
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308 /*-----------------------------------------------------------*/
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310 void vLCDTask( void * pvParameters )
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312 unsigned portBASE_TYPE uxIndex;
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313 const unsigned portCHAR ucCFGData[] = {
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314 0x30, /* Set data bus to 8-bits. */
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317 0x3C, /* Number of lines/font. */
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318 0x08, /* Display off. */
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319 0x01, /* Display clear. */
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320 0x06, /* Entry mode [cursor dir][shift]. */
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321 0x0C /* Display on [display on][curson on][blinking on]. */
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324 /* The strings that are written to the LCD. */
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325 const portCHAR *pcStringsToDisplay[] = {
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329 "www.FreeRTOS.org",
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333 /* Configure the LCD. */
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335 while( uxIndex < sizeof( ucCFGData ) )
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337 prvPDCWrite( PDC_LCD_CSR, ucCFGData[ uxIndex ] );
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339 vTaskDelay( mainCHAR_WRITE_DELAY );
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342 /* Turn the LCD Backlight on. */
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343 prvPDCWrite( PDC_CSR, 0x01 );
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345 /* Clear display. */
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346 vTaskDelay( mainCHAR_WRITE_DELAY );
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347 prvPDCWrite( PDC_LCD_CSR, LCD_CLEAR );
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352 /* Display the string on the LCD. */
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353 prvWriteString( pcStringsToDisplay[ uxIndex ] );
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355 /* Move on to the next string - wrapping if necessary. */
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357 if( *( pcStringsToDisplay[ uxIndex ] ) == 0x00 )
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360 /* Longer pause on the last string to be sent. */
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361 vTaskDelay( mainSTRING_WRITE_DELAY * 2 );
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364 /* Wait until it is time to move onto the next string. */
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365 vTaskDelay( mainSTRING_WRITE_DELAY );
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368 /*-----------------------------------------------------------*/
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370 static void vCommsRxCoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex )
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372 static portCHAR cRxedChar, cExpectedChar = mainFIRST_TX_CHAR;
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373 portBASE_TYPE xResult;
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375 crSTART( xHandle );
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379 /* Wait for a character to be received. */
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380 crQUEUE_RECEIVE( xHandle, xCommsQueue, ( void * ) &cRxedChar, mainCOMMS_RX_DELAY, &xResult );
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382 /* Was the character recived (if any) the expected character. */
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383 if( ( cRxedChar != cExpectedChar ) || ( xResult != pdPASS ) )
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385 /* Got an unexpected character. This can sometimes occur when
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386 reseting the system using the debugger leaving characters already
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387 in the UART regsters. */
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388 uxErrorStatus = pdFAIL;
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390 /* Resync by waiting for the end of the current string. */
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391 while( cRxedChar != mainLAST_TX_CHAR )
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393 crQUEUE_RECEIVE( xHandle, xCommsQueue, ( void * ) &cRxedChar, mainCOMMS_RX_DELAY, &xResult );
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396 /* The next expected character is the start of the string again. */
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397 cExpectedChar = mainFIRST_TX_CHAR;
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401 if( cExpectedChar == mainLAST_TX_CHAR )
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403 /* We have reached the end of the string - we now expect to
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404 receive the first character in the string again. The LED is
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405 toggled to indicate that the entire string was received without
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407 vParTestToggleLED( mainCOMMS_RX_LED );
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408 cExpectedChar = mainFIRST_TX_CHAR;
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412 /* We got the expected character, we now expect to receive the
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413 next character in the string. */
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421 /*-----------------------------------------------------------*/
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423 static void vSerialTxCoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex )
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425 portTickType xDelayPeriod;
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426 static unsigned portLONG *pulRandomBytes = mainFIRST_PROGRAM_BYTES;
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428 /* Co-routine MUST start with a call to crSTART. */
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429 crSTART( xHandle );
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433 /* Was the previously transmitted string received correctly? */
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434 if( uxErrorStatus != pdPASS )
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436 /* An error was encountered so set the error LED. */
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440 /* The next character to Tx is the first in the string. */
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441 cNextChar = mainFIRST_TX_CHAR;
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443 UARTIntDisable( UART0_BASE, UART_INT_TX );
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445 /* Send the first character. */
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446 if( !( HWREG( UART0_BASE + UART_O_FR ) & UART_FR_TXFF ) )
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448 HWREG( UART0_BASE + UART_O_DR ) = cNextChar;
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451 /* Move the variable to the char to Tx on so the ISR transmits
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452 the next character in the string once this one has completed. */
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455 UARTIntEnable(UART0_BASE, UART_INT_TX);
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457 /* Toggle the LED to show a new string is being transmitted. */
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458 vParTestToggleLED( mainCOMMS_TX_LED );
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460 /* Delay before we start the string off again. A pseudo-random delay
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461 is used as this will provide a better test. */
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462 xDelayPeriod = xTaskGetTickCount() + ( *pulRandomBytes );
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465 if( pulRandomBytes > mainTOTAL_PROGRAM_MEMORY )
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467 pulRandomBytes = mainFIRST_PROGRAM_BYTES;
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470 /* Make sure we don't wait too long... */
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471 xDelayPeriod &= mainMAX_TX_DELAY;
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473 /* ...but we do want to wait. */
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474 if( xDelayPeriod < mainMIN_TX_DELAY )
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476 xDelayPeriod = mainMIN_TX_DELAY;
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479 /* Block for the random(ish) time. */
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480 crDELAY( xHandle, xDelayPeriod );
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483 /* Co-routine MUST end with a call to crEND. */
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486 /*-----------------------------------------------------------*/
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488 static void vSerialInit( void )
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490 /* Enable the UART. GPIOA has already been initialised. */
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491 SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);
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493 /* Set GPIO A0 and A1 as peripheral function. They are used to output the
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495 GPIODirModeSet( GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1, GPIO_DIR_MODE_HW );
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497 /* Configure the UART for 8-N-1 operation. */
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498 UARTConfigSet( UART0_BASE, mainBAUD_RATE, UART_CONFIG_WLEN_8 | UART_CONFIG_PAR_NONE | UART_CONFIG_STOP_ONE );
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500 /* We dont want to use the fifo. This is for test purposes to generate
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501 as many interrupts as possible. */
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502 HWREG( UART0_BASE + UART_O_LCR_H ) &= ~mainFIFO_SET;
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504 /* Enable both Rx and Tx interrupts. */
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505 HWREG( UART0_BASE + UART_O_IM ) |= ( UART_INT_TX | UART_INT_RX );
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506 IntEnable( INT_UART0 );
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508 /*-----------------------------------------------------------*/
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510 void vUART_ISR(void)
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512 unsigned portLONG ulStatus;
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513 portCHAR cRxedChar;
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514 portBASE_TYPE xTaskWokenByPost = pdFALSE;
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516 /* What caused the interrupt. */
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517 ulStatus = UARTIntStatus( UART0_BASE, pdTRUE );
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519 /* Clear the interrupt. */
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520 UARTIntClear( UART0_BASE, ulStatus );
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522 /* Was an Rx interrpt pending? */
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523 if( ulStatus & UART_INT_RX )
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525 if( ( HWREG(UART0_BASE + UART_O_FR ) & UART_FR_RXFF ) )
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527 /* Get the char from the buffer and post it onto the queue of
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528 Rxed chars. Posting the character should wake the task that is
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529 blocked on the queue waiting for characters. */
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530 cRxedChar = ( portCHAR ) HWREG( UART0_BASE + UART_O_DR );
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531 xTaskWokenByPost = crQUEUE_SEND_FROM_ISR( xCommsQueue, &cRxedChar, xTaskWokenByPost );
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535 /* Was a Tx interrupt pending? */
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536 if( ulStatus & UART_INT_TX )
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538 /* Send the next character in the string. We are not using the FIFO. */
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539 if( cNextChar <= mainLAST_TX_CHAR )
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541 if( !( HWREG( UART0_BASE + UART_O_FR ) & UART_FR_TXFF ) )
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543 HWREG( UART0_BASE + UART_O_DR ) = cNextChar;
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549 if( xTaskWokenByPost )
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551 /* We are posting to a co-routine rather than a task so don't bother
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552 causing a task switch. */
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555 /*-----------------------------------------------------------*/
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557 static void prvPDCWrite( portCHAR cAddress, portCHAR cData )
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561 PDCWrite( cAddress, cData );
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565 /*-----------------------------------------------------------*/
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567 void vSetErrorLED( void )
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569 vParTestSetLED( mainCOMMS_FAIL_LED, pdTRUE );
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571 /*-----------------------------------------------------------*/
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573 void prvSetAndCheckRegisters( void )
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575 /* Fill the general purpose registers with known values. */
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576 __asm volatile( " mov r11, #10\n"
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577 " add r0, r11, #1\n"
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578 " add r1, r11, #2\n"
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579 " add r2, r11, #3\n"
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580 " add r3, r11, #4\n"
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581 " add r4, r11, #5\n"
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582 " add r5, r11, #6\n"
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583 " add r6, r11, #7\n"
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584 " add r7, r11, #8\n"
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585 " add r12, r11, #12" );
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587 /* Check the values are as expected. */
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588 __asm volatile( " cmp r11, #10\n"
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589 " bne set_error_led\n"
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591 " bne set_error_led\n"
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593 " bne set_error_led\n"
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595 " bne set_error_led\n"
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597 " bne set_error_led\n"
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599 " bne set_error_led\n"
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601 " bne set_error_led\n"
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603 " bne set_error_led\n"
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605 " bne set_error_led\n"
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607 " bne set_error_led\n"
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610 __asm volatile( "set_error_led:\n"
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612 " ldr r1, =vSetErrorLED\n"
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617 /*-----------------------------------------------------------*/
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projects / freertos / blob