2 FreeRTOS V7.2.0 - Copyright (C) 2012 Real Time Engineers Ltd.
\r
5 ***************************************************************************
\r
7 * FreeRTOS tutorial books are available in pdf and paperback. *
\r
8 * Complete, revised, and edited pdf reference manuals are also *
\r
11 * Purchasing FreeRTOS documentation will not only help you, by *
\r
12 * ensuring you get running as quickly as possible and with an *
\r
13 * in-depth knowledge of how to use FreeRTOS, it will also help *
\r
14 * the FreeRTOS project to continue with its mission of providing *
\r
15 * professional grade, cross platform, de facto standard solutions *
\r
16 * for microcontrollers - completely free of charge! *
\r
18 * >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
\r
20 * Thank you for using FreeRTOS, and thank you for your support! *
\r
22 ***************************************************************************
\r
25 This file is part of the FreeRTOS distribution.
\r
27 FreeRTOS is free software; you can redistribute it and/or modify it under
\r
28 the terms of the GNU General Public License (version 2) as published by the
\r
29 Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
\r
30 >>>NOTE<<< The modification to the GPL is included to allow you to
\r
31 distribute a combined work that includes FreeRTOS without being obliged to
\r
32 provide the source code for proprietary components outside of the FreeRTOS
\r
33 kernel. FreeRTOS is distributed in the hope that it will be useful, but
\r
34 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
\r
35 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
\r
36 more details. You should have received a copy of the GNU General Public
\r
37 License and the FreeRTOS license exception along with FreeRTOS; if not it
\r
38 can be viewed here: http://www.freertos.org/a00114.html and also obtained
\r
39 by writing to Richard Barry, contact details for whom are available on the
\r
44 ***************************************************************************
\r
46 * Having a problem? Start by reading the FAQ "My application does *
\r
47 * not run, what could be wrong? *
\r
49 * http://www.FreeRTOS.org/FAQHelp.html *
\r
51 ***************************************************************************
\r
54 http://www.FreeRTOS.org - Documentation, training, latest information,
\r
55 license and contact details.
\r
57 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
\r
58 including FreeRTOS+Trace - an indispensable productivity tool.
\r
60 Real Time Engineers ltd license FreeRTOS to High Integrity Systems, who sell
\r
61 the code with commercial support, indemnification, and middleware, under
\r
62 the OpenRTOS brand: http://www.OpenRTOS.com. High Integrity Systems also
\r
63 provide a safety engineered and independently SIL3 certified version under
\r
64 the SafeRTOS brand: http://www.SafeRTOS.com.
\r
68 * This demo application creates seven co-routines and one task (two including
\r
69 * the idle task). The co-routines execute as part of the idle task hook.
\r
71 * Five of the created co-routines are the standard 'co-routine flash'
\r
72 * co-routines contained within the Demo/Common/Minimal/crflash.c file and
\r
73 * documented on the FreeRTOS.org WEB site.
\r
75 * The 'LCD Task' rotates a string on the LCD, delaying between each character
\r
76 * as necessitated by the slow interface, and delaying between each string just
\r
77 * long enough to enable the text to be read.
\r
79 * The sixth co-routine controls the transmission of a string to UART 0. The
\r
80 * co-routine periodically sends the first character of the string to the UART,
\r
81 * with the UART's TxEnd interrupt being used to transmit the remaining
\r
82 * characters. The UART's RxEnd interrupt receives the characters and places
\r
83 * them on a queue to be processed by the seventh and final co-routine. An
\r
84 * error is latched should an unexpected character be received, or any
\r
85 * character be received out of sequence.
\r
87 * A loopback connector is required to ensure that each character transmitted
\r
88 * on the UART is also received on the same UART. For test purposes the UART
\r
89 * FIFO's are not utalised in order to maximise the interrupt overhead. Also
\r
90 * a pseudo random interval is used between the start of each transmission in
\r
91 * order that the resultant interrupts are more randomly distributed and
\r
92 * therefore more likely to highlight any problems.
\r
94 * The flash co-routines control LED's zero to four. LED five is toggled each
\r
95 * time the string is transmitted on the UART. LED six is toggled each time
\r
96 * the string is CORRECTLY received on the UART. LED seven is latched on should
\r
97 * an error be detected in any task or co-routine.
\r
99 * In addition the idle task makes repetative calls to
\r
100 * prvSetAndCheckRegisters(). This simply loads the general purpose registers
\r
101 * with a known value, then checks each register to ensure the held value is
\r
102 * still correct. As a low priority task this checking routine is likely to
\r
103 * get repeatedly swapped in and out. A register being found to contain an
\r
104 * incorrect value is therefore indicative of an error in the task switching
\r
109 /* Scheduler include files. */
\r
110 #include "FreeRTOS.h"
\r
113 #include "croutine.h"
\r
115 /* Demo application include files. */
\r
116 #include "partest.h"
\r
117 #include "crflash.h"
\r
119 /* Library include files. */
\r
120 #include "DriverLib.h"
\r
122 /* The time to delay between writing each character to the LCD. */
\r
123 #define mainCHAR_WRITE_DELAY ( 2 / portTICK_RATE_MS )
\r
125 /* The time to delay between writing each string to the LCD. */
\r
126 #define mainSTRING_WRITE_DELAY ( 400 / portTICK_RATE_MS )
\r
128 /* The number of flash co-routines to create. */
\r
129 #define mainNUM_FLASH_CO_ROUTINES ( 5 )
\r
131 /* The length of the queue used to pass received characters to the Comms Rx
\r
133 #define mainRX_QUEUE_LEN ( 5 )
\r
135 /* The priority of the co-routine used to initiate the transmission of the
\r
136 string on UART 0. */
\r
137 #define mainTX_CO_ROUTINE_PRIORITY ( 1 )
\r
139 /* The priority of the co-routine used to receive characters from the UART. */
\r
140 #define mainRX_CO_ROUTINE_PRIORITY ( 2 )
\r
142 /* Only one co-routine is created so its index is not important. */
\r
143 #define mainTX_CO_ROUTINE_INDEX ( 0 )
\r
144 #define mainRX_CO_ROUTINE_INDEX ( 0 )
\r
146 /* The time between transmissions of the string on UART 0. This is pseudo
\r
147 random in order to generate a bit or randomness to when the interrupts occur.*/
\r
148 #define mainMIN_TX_DELAY ( 40 / portTICK_RATE_MS )
\r
149 #define mainMAX_TX_DELAY ( ( portTickType ) 0x7f )
\r
150 #define mainOFFSET_TIME ( ( portTickType ) 3 )
\r
152 /* The time the Comms Rx task should wait to receive a character. This should
\r
153 be slightly longer than the time between transmissions. If we do not receive
\r
154 a character after this time then there must be an error in the transmission or
\r
155 the timing of the transmission. */
\r
156 #define mainCOMMS_RX_DELAY ( mainMAX_TX_DELAY + 20 )
\r
158 /* The task priorites. */
\r
159 #define mainLCD_TASK_PRIORITY ( tskIDLE_PRIORITY )
\r
160 #define mainCOMMS_RX_TASK_PRIORITY ( tskIDLE_PRIORITY + 1 )
\r
162 /* The LED's toggled by the various tasks. */
\r
163 #define mainCOMMS_FAIL_LED ( 7 )
\r
164 #define mainCOMMS_RX_LED ( 6 )
\r
165 #define mainCOMMS_TX_LED ( 5 )
\r
167 /* The baud rate used by the UART comms tasks/co-routine. */
\r
168 #define mainBAUD_RATE ( 57600 )
\r
170 /* FIFO setting for the UART. The FIFO is not used to create a better test. */
\r
171 #define mainFIFO_SET ( 0x10 )
\r
173 /* The string that is transmitted on the UART contains sequentially the
\r
174 characters from mainFIRST_TX_CHAR to mainLAST_TX_CHAR. */
\r
175 #define mainFIRST_TX_CHAR '0'
\r
176 #define mainLAST_TX_CHAR 'z'
\r
178 /* Just used to walk through the program memory in order that some random data
\r
179 can be generated. */
\r
180 #define mainTOTAL_PROGRAM_MEMORY ( ( unsigned long * ) ( 8 * 1024 ) )
\r
181 #define mainFIRST_PROGRAM_BYTES ( ( unsigned long * ) 4 )
\r
183 /* The error routine that is called if the driver library encounters an error. */
\r
186 __error__(char *pcFilename, unsigned long ulLine)
\r
191 /*-----------------------------------------------------------*/
\r
194 * The task that rotates text on the LCD.
\r
196 static void vLCDTask( void * pvParameters );
\r
199 * The task that receives the characters from UART 0.
\r
201 static void vCommsRxCoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex );
\r
204 * The co-routine that periodically initiates the transmission of the string on
\r
207 static void vSerialTxCoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex );
\r
210 * Writes a string the the LCD.
\r
212 static void prvWriteString( const char *pcString );
\r
215 * Initialisation routine for the UART.
\r
217 static void vSerialInit( void );
\r
220 * Thread safe write to the PDC.
\r
222 static void prvPDCWrite( char cAddress, char cData );
\r
225 * Function to simply set a known value into the general purpose registers
\r
226 * then read them back to ensure they remain set correctly. An incorrect value
\r
227 * being indicative of an error in the task switching mechanism.
\r
229 void prvSetAndCheckRegisters( void );
\r
232 * Latch the LED that indicates that an error has occurred.
\r
234 void vSetErrorLED( void );
\r
237 * Sets up the PLL and ports used by the demo.
\r
239 static void prvSetupHardware( void );
\r
241 /*-----------------------------------------------------------*/
\r
243 /* Error flag set to pdFAIL if an error is encountered in the tasks/co-routines
\r
244 defined within this file. */
\r
245 unsigned portBASE_TYPE uxErrorStatus = pdPASS;
\r
247 /* The next character to transmit. */
\r
248 static char cNextChar;
\r
250 /* The queue used to transmit characters from the interrupt to the Comms Rx
\r
252 static xQueueHandle xCommsQueue;
\r
254 /*-----------------------------------------------------------*/
\r
258 /* Create the queue used to communicate between the UART ISR and the Comms
\r
260 xCommsQueue = xQueueCreate( mainRX_QUEUE_LEN, sizeof( char ) );
\r
262 /* Setup the ports used by the demo and the clock. */
\r
263 prvSetupHardware();
\r
265 /* Create the co-routines that flash the LED's. */
\r
266 vStartFlashCoRoutines( mainNUM_FLASH_CO_ROUTINES );
\r
268 /* Create the co-routine that initiates the transmission of characters
\r
270 xCoRoutineCreate( vSerialTxCoRoutine, mainTX_CO_ROUTINE_PRIORITY, mainTX_CO_ROUTINE_INDEX );
\r
272 /* Create the co-routine that receives characters from the UART. */
\r
273 xCoRoutineCreate( vCommsRxCoRoutine, mainRX_CO_ROUTINE_PRIORITY, mainRX_CO_ROUTINE_INDEX );
\r
275 /* Create the LCD task. */
\r
276 xTaskCreate( vLCDTask, "LCD", configMINIMAL_STACK_SIZE, NULL, mainLCD_TASK_PRIORITY, NULL );
\r
278 /* Start the scheduler running the tasks and co-routines just created. */
\r
279 vTaskStartScheduler();
\r
281 /* Should not get here unless we did not have enough memory to start the
\r
286 /*-----------------------------------------------------------*/
\r
288 static void prvSetupHardware( void )
\r
290 /* Setup the PLL. */
\r
291 SysCtlClockSet( SYSCTL_SYSDIV_10 | SYSCTL_USE_PLL | SYSCTL_OSC_MAIN | SYSCTL_XTAL_6MHZ );
\r
293 /* Initialise the hardware used to talk to the LCD, LED's and UART. */
\r
295 vParTestInitialise();
\r
298 /*-----------------------------------------------------------*/
\r
300 void vApplicationIdleHook( void )
\r
302 /* The co-routines are executed in the idle task using the idle task
\r
306 /* Schedule the co-routines. */
\r
307 vCoRoutineSchedule();
\r
309 /* Run the register check function between each co-routine. */
\r
310 prvSetAndCheckRegisters();
\r
313 /*-----------------------------------------------------------*/
\r
315 static void prvWriteString( const char *pcString )
\r
317 /* Write pcString to the LED, pausing between each character. */
\r
318 prvPDCWrite(PDC_LCD_CSR, LCD_CLEAR);
\r
321 vTaskDelay( mainCHAR_WRITE_DELAY );
\r
322 prvPDCWrite( PDC_LCD_RAM, *pcString );
\r
326 /*-----------------------------------------------------------*/
\r
328 void vLCDTask( void * pvParameters )
\r
330 unsigned portBASE_TYPE uxIndex;
\r
331 const unsigned char ucCFGData[] = {
\r
332 0x30, /* Set data bus to 8-bits. */
\r
335 0x3C, /* Number of lines/font. */
\r
336 0x08, /* Display off. */
\r
337 0x01, /* Display clear. */
\r
338 0x06, /* Entry mode [cursor dir][shift]. */
\r
339 0x0C /* Display on [display on][curson on][blinking on]. */
\r
342 /* The strings that are written to the LCD. */
\r
343 const char *pcStringsToDisplay[] = {
\r
347 "www.FreeRTOS.org",
\r
351 /* Configure the LCD. */
\r
353 while( uxIndex < sizeof( ucCFGData ) )
\r
355 prvPDCWrite( PDC_LCD_CSR, ucCFGData[ uxIndex ] );
\r
357 vTaskDelay( mainCHAR_WRITE_DELAY );
\r
360 /* Turn the LCD Backlight on. */
\r
361 prvPDCWrite( PDC_CSR, 0x01 );
\r
363 /* Clear display. */
\r
364 vTaskDelay( mainCHAR_WRITE_DELAY );
\r
365 prvPDCWrite( PDC_LCD_CSR, LCD_CLEAR );
\r
370 /* Display the string on the LCD. */
\r
371 prvWriteString( pcStringsToDisplay[ uxIndex ] );
\r
373 /* Move on to the next string - wrapping if necessary. */
\r
375 if( *( pcStringsToDisplay[ uxIndex ] ) == 0x00 )
\r
378 /* Longer pause on the last string to be sent. */
\r
379 vTaskDelay( mainSTRING_WRITE_DELAY * 2 );
\r
382 /* Wait until it is time to move onto the next string. */
\r
383 vTaskDelay( mainSTRING_WRITE_DELAY );
\r
386 /*-----------------------------------------------------------*/
\r
388 static void vCommsRxCoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex )
\r
390 static char cRxedChar, cExpectedChar = mainFIRST_TX_CHAR;
\r
391 portBASE_TYPE xResult;
\r
393 crSTART( xHandle );
\r
397 /* Wait for a character to be received. */
\r
398 crQUEUE_RECEIVE( xHandle, xCommsQueue, ( void * ) &cRxedChar, mainCOMMS_RX_DELAY, &xResult );
\r
400 /* Was the character recived (if any) the expected character. */
\r
401 if( ( cRxedChar != cExpectedChar ) || ( xResult != pdPASS ) )
\r
403 /* Got an unexpected character. This can sometimes occur when
\r
404 reseting the system using the debugger leaving characters already
\r
405 in the UART regsters. */
\r
406 uxErrorStatus = pdFAIL;
\r
408 /* Resync by waiting for the end of the current string. */
\r
409 while( cRxedChar != mainLAST_TX_CHAR )
\r
411 crQUEUE_RECEIVE( xHandle, xCommsQueue, ( void * ) &cRxedChar, mainCOMMS_RX_DELAY, &xResult );
\r
414 /* The next expected character is the start of the string again. */
\r
415 cExpectedChar = mainFIRST_TX_CHAR;
\r
419 if( cExpectedChar == mainLAST_TX_CHAR )
\r
421 /* We have reached the end of the string - we now expect to
\r
422 receive the first character in the string again. The LED is
\r
423 toggled to indicate that the entire string was received without
\r
425 vParTestToggleLED( mainCOMMS_RX_LED );
\r
426 cExpectedChar = mainFIRST_TX_CHAR;
\r
430 /* We got the expected character, we now expect to receive the
\r
431 next character in the string. */
\r
439 /*-----------------------------------------------------------*/
\r
441 static void vSerialTxCoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex )
\r
443 portTickType xDelayPeriod;
\r
444 static unsigned long *pulRandomBytes = mainFIRST_PROGRAM_BYTES;
\r
446 /* Co-routine MUST start with a call to crSTART. */
\r
447 crSTART( xHandle );
\r
451 /* Was the previously transmitted string received correctly? */
\r
452 if( uxErrorStatus != pdPASS )
\r
454 /* An error was encountered so set the error LED. */
\r
458 /* The next character to Tx is the first in the string. */
\r
459 cNextChar = mainFIRST_TX_CHAR;
\r
461 UARTIntDisable( UART0_BASE, UART_INT_TX );
\r
463 /* Send the first character. */
\r
464 if( !( HWREG( UART0_BASE + UART_O_FR ) & UART_FR_TXFF ) )
\r
466 HWREG( UART0_BASE + UART_O_DR ) = cNextChar;
\r
469 /* Move the variable to the char to Tx on so the ISR transmits
\r
470 the next character in the string once this one has completed. */
\r
473 UARTIntEnable(UART0_BASE, UART_INT_TX);
\r
475 /* Toggle the LED to show a new string is being transmitted. */
\r
476 vParTestToggleLED( mainCOMMS_TX_LED );
\r
478 /* Delay before we start the string off again. A pseudo-random delay
\r
479 is used as this will provide a better test. */
\r
480 xDelayPeriod = xTaskGetTickCount() + ( *pulRandomBytes );
\r
483 if( pulRandomBytes > mainTOTAL_PROGRAM_MEMORY )
\r
485 pulRandomBytes = mainFIRST_PROGRAM_BYTES;
\r
488 /* Make sure we don't wait too long... */
\r
489 xDelayPeriod &= mainMAX_TX_DELAY;
\r
491 /* ...but we do want to wait. */
\r
492 if( xDelayPeriod < mainMIN_TX_DELAY )
\r
494 xDelayPeriod = mainMIN_TX_DELAY;
\r
497 /* Block for the random(ish) time. */
\r
498 crDELAY( xHandle, xDelayPeriod );
\r
501 /* Co-routine MUST end with a call to crEND. */
\r
504 /*-----------------------------------------------------------*/
\r
506 static void vSerialInit( void )
\r
508 /* Enable the UART. GPIOA has already been initialised. */
\r
509 SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);
\r
511 /* Set GPIO A0 and A1 as peripheral function. They are used to output the
\r
513 GPIODirModeSet( GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1, GPIO_DIR_MODE_HW );
\r
515 /* Configure the UART for 8-N-1 operation. */
\r
516 UARTConfigSet( UART0_BASE, mainBAUD_RATE, UART_CONFIG_WLEN_8 | UART_CONFIG_PAR_NONE | UART_CONFIG_STOP_ONE );
\r
518 /* We dont want to use the fifo. This is for test purposes to generate
\r
519 as many interrupts as possible. */
\r
520 HWREG( UART0_BASE + UART_O_LCR_H ) &= ~mainFIFO_SET;
\r
522 /* Enable both Rx and Tx interrupts. */
\r
523 HWREG( UART0_BASE + UART_O_IM ) |= ( UART_INT_TX | UART_INT_RX );
\r
524 IntEnable( INT_UART0 );
\r
526 /*-----------------------------------------------------------*/
\r
528 void vUART_ISR(void)
\r
530 unsigned long ulStatus;
\r
532 portBASE_TYPE xTaskWokenByPost = pdFALSE;
\r
534 /* What caused the interrupt. */
\r
535 ulStatus = UARTIntStatus( UART0_BASE, pdTRUE );
\r
537 /* Clear the interrupt. */
\r
538 UARTIntClear( UART0_BASE, ulStatus );
\r
540 /* Was an Rx interrpt pending? */
\r
541 if( ulStatus & UART_INT_RX )
\r
543 if( ( HWREG(UART0_BASE + UART_O_FR ) & UART_FR_RXFF ) )
\r
545 /* Get the char from the buffer and post it onto the queue of
\r
546 Rxed chars. Posting the character should wake the task that is
\r
547 blocked on the queue waiting for characters. */
\r
548 cRxedChar = ( char ) HWREG( UART0_BASE + UART_O_DR );
\r
549 xTaskWokenByPost = crQUEUE_SEND_FROM_ISR( xCommsQueue, &cRxedChar, xTaskWokenByPost );
\r
553 /* Was a Tx interrupt pending? */
\r
554 if( ulStatus & UART_INT_TX )
\r
556 /* Send the next character in the string. We are not using the FIFO. */
\r
557 if( cNextChar <= mainLAST_TX_CHAR )
\r
559 if( !( HWREG( UART0_BASE + UART_O_FR ) & UART_FR_TXFF ) )
\r
561 HWREG( UART0_BASE + UART_O_DR ) = cNextChar;
\r
567 if( xTaskWokenByPost )
\r
569 /* We are posting to a co-routine rather than a task so don't bother
\r
570 causing a task switch. */
\r
573 /*-----------------------------------------------------------*/
\r
575 static void prvPDCWrite( char cAddress, char cData )
\r
579 PDCWrite( cAddress, cData );
\r
583 /*-----------------------------------------------------------*/
\r
585 void vSetErrorLED( void )
\r
587 vParTestSetLED( mainCOMMS_FAIL_LED, pdTRUE );
\r
589 /*-----------------------------------------------------------*/
\r
591 void prvSetAndCheckRegisters( void )
\r
593 /* Fill the general purpose registers with known values. */
\r
597 " add r0, r11, #1 \n"
\r
598 " add r1, r11, #2 \n"
\r
599 " add r2, r11, #3 \n"
\r
600 " add r3, r11, #4 \n"
\r
601 " add r4, r11, #5 \n"
\r
602 " add r5, r11, #6 \n"
\r
603 " add r6, r11, #7 \n"
\r
604 " add r7, r11, #8 \n"
\r
605 " add r8, r11, #9 \n"
\r
606 " add r9, r11, #10 \n"
\r
607 " add r10, r11, #11 \n"
\r
608 " add r12, r11, #12"
\r
611 /* Check the values are as expected. */
\r
615 " bne set_error_led \n"
\r
617 " bne set_error_led \n"
\r
619 " bne set_error_led \n"
\r
621 " bne set_error_led \n"
\r
623 " bne set_error_led \n"
\r
625 " bne set_error_led \n"
\r
627 " bne set_error_led \n"
\r
629 " bne set_error_led \n"
\r
631 " bne set_error_led \n"
\r
633 " bne set_error_led \n"
\r
635 " bne set_error_led \n"
\r
637 " bne set_error_led \n"
\r
639 " bne set_error_led \n"
\r
645 "set_error_led: \n"
\r
647 " ldr r1, vSetErrorLEDConst\n"
\r
653 "vSetErrorLEDConst: .word vSetErrorLED"
\r
656 /*-----------------------------------------------------------*/
\r