2 FreeRTOS V7.3.0 - Copyright (C) 2012 Real Time Engineers Ltd.
\r
4 FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME. PLEASE VISIT
\r
5 http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
\r
7 ***************************************************************************
\r
9 * FreeRTOS tutorial books are available in pdf and paperback. *
\r
10 * Complete, revised, and edited pdf reference manuals are also *
\r
13 * Purchasing FreeRTOS documentation will not only help you, by *
\r
14 * ensuring you get running as quickly as possible and with an *
\r
15 * in-depth knowledge of how to use FreeRTOS, it will also help *
\r
16 * the FreeRTOS project to continue with its mission of providing *
\r
17 * professional grade, cross platform, de facto standard solutions *
\r
18 * for microcontrollers - completely free of charge! *
\r
20 * >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
\r
22 * Thank you for using FreeRTOS, and thank you for your support! *
\r
24 ***************************************************************************
\r
27 This file is part of the FreeRTOS distribution.
\r
29 FreeRTOS is free software; you can redistribute it and/or modify it under
\r
30 the terms of the GNU General Public License (version 2) as published by the
\r
31 Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
\r
32 >>>NOTE<<< The modification to the GPL is included to allow you to
\r
33 distribute a combined work that includes FreeRTOS without being obliged to
\r
34 provide the source code for proprietary components outside of the FreeRTOS
\r
35 kernel. FreeRTOS is distributed in the hope that it will be useful, but
\r
36 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
\r
37 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
\r
38 more details. You should have received a copy of the GNU General Public
\r
39 License and the FreeRTOS license exception along with FreeRTOS; if not it
\r
40 can be viewed here: http://www.freertos.org/a00114.html and also obtained
\r
41 by writing to Richard Barry, contact details for whom are available on the
\r
46 ***************************************************************************
\r
48 * Having a problem? Start by reading the FAQ "My application does *
\r
49 * not run, what could be wrong?" *
\r
51 * http://www.FreeRTOS.org/FAQHelp.html *
\r
53 ***************************************************************************
\r
56 http://www.FreeRTOS.org - Documentation, training, latest versions, license
\r
57 and contact details.
\r
59 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
\r
60 including FreeRTOS+Trace - an indispensable productivity tool.
\r
62 Real Time Engineers ltd license FreeRTOS to High Integrity Systems, who sell
\r
63 the code with commercial support, indemnification, and middleware, under
\r
64 the OpenRTOS brand: http://www.OpenRTOS.com. High Integrity Systems also
\r
65 provide a safety engineered and independently SIL3 certified version under
\r
66 the SafeRTOS brand: http://www.SafeRTOS.com.
\r
70 BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR UART0.
\r
72 ***Note*** This example uses queues to send each character into an interrupt
\r
73 service routine and out of an interrupt service routine individually. This
\r
74 is done to demonstrate queues being used in an interrupt, and to deliberately
\r
75 load the system to test the FreeRTOS port. It is *NOT* meant to be an
\r
76 example of an efficient implementation. An efficient implementation should
\r
77 use FIFO's or DMA if available, and only use FreeRTOS API functions when
\r
78 enough has been received to warrant a task being unblocked to process the
\r
82 /* Scheduler includes. */
\r
83 #include "FreeRTOS.h"
\r
86 #include "comtest2.h"
\r
88 /* Library includes. */
\r
89 #include "stm32l152_eval.h"
\r
91 /* Demo application includes. */
\r
93 /*-----------------------------------------------------------*/
\r
96 #define serINVALID_QUEUE ( ( xQueueHandle ) 0 )
\r
97 #define serNO_BLOCK ( ( portTickType ) 0 )
\r
99 /*-----------------------------------------------------------*/
\r
101 /* The queue used to hold received characters. */
\r
102 static xQueueHandle xRxedChars;
\r
103 static xQueueHandle xCharsForTx;
\r
105 /*-----------------------------------------------------------*/
\r
108 * See the serial2.h header file.
\r
110 xComPortHandle xSerialPortInitMinimal( unsigned portLONG ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
\r
112 USART_InitTypeDef USART_InitStructure;
\r
113 xComPortHandle xReturn;
\r
114 NVIC_InitTypeDef NVIC_InitStructure;
\r
116 /* Create the queues used to hold Rx/Tx characters. */
\r
117 xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
\r
118 xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
\r
120 /* If the queues were created correctly then setup the serial port
\r
122 if( ( xRxedChars != serINVALID_QUEUE ) && ( xCharsForTx != serINVALID_QUEUE ) )
\r
124 USART_InitStructure.USART_BaudRate = ulWantedBaud;
\r
125 USART_InitStructure.USART_WordLength = USART_WordLength_8b;
\r
126 USART_InitStructure.USART_StopBits = USART_StopBits_1;
\r
127 USART_InitStructure.USART_Parity = USART_Parity_No;
\r
128 USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
\r
129 USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
\r
131 /* The Eval board COM2 is being used, which in reality is the STM32
\r
133 STM_EVAL_COMInit( COM2, &USART_InitStructure );
\r
135 NVIC_InitStructure.NVIC_IRQChannel = USART3_IRQn;
\r
136 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY;
\r
137 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; /* Not used as 4 bits are used for the pre-emption priority. */;
\r
138 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
\r
139 NVIC_Init( &NVIC_InitStructure );
\r
140 USART_ITConfig( USART3, USART_IT_RXNE, ENABLE );
\r
144 xReturn = ( xComPortHandle ) 0;
\r
147 /* This demo file only supports a single port but we have to return
\r
148 something to comply with the standard demo header file. */
\r
151 /*-----------------------------------------------------------*/
\r
153 signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed portCHAR *pcRxedChar, portTickType xBlockTime )
\r
155 /* The port handle is not required as this driver only supports one port. */
\r
158 /* Get the next character from the buffer. Return false if no characters
\r
159 are available, or arrive before xBlockTime expires. */
\r
160 if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
\r
169 /*-----------------------------------------------------------*/
\r
171 void vSerialPutString( xComPortHandle pxPort, const signed portCHAR * const pcString, unsigned portSHORT usStringLength )
\r
173 signed portCHAR *pxNext;
\r
175 /* A couple of parameters that this port does not use. */
\r
176 ( void ) usStringLength;
\r
179 /* NOTE: This implementation does not handle the queue being full as no
\r
180 block time is used! */
\r
182 /* The port handle is not required as this driver only supports UART1. */
\r
185 /* Send each character in the string, one at a time. */
\r
186 pxNext = ( signed portCHAR * ) pcString;
\r
189 xSerialPutChar( pxPort, *pxNext, serNO_BLOCK );
\r
193 /*-----------------------------------------------------------*/
\r
195 signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed portCHAR cOutChar, portTickType xBlockTime )
\r
197 signed portBASE_TYPE xReturn;
\r
199 if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) == pdPASS )
\r
202 USART_ITConfig( USART3, USART_IT_TXE, ENABLE );
\r
211 /*-----------------------------------------------------------*/
\r
213 void vSerialClose( xComPortHandle xPort )
\r
215 /* Not supported as not required by the demo application. */
\r
217 /*-----------------------------------------------------------*/
\r
219 void USART3_IRQHandler( void )
\r
221 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
\r
224 if( USART_GetITStatus( USART3, USART_IT_TXE ) == SET )
\r
226 /* The interrupt was caused by the TX register becoming empty. Are
\r
227 there any more characters to transmit? */
\r
228 if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )
\r
230 /* A character was retrieved from the queue so can be sent to the
\r
232 USART_SendData( USART3, cChar );
\r
236 USART_ITConfig( USART3, USART_IT_TXE, DISABLE );
\r
240 if( USART_GetITStatus( USART3, USART_IT_RXNE ) == SET )
\r
242 /* A character has been received on the USART, send it to the Rx
\r
244 cChar = USART_ReceiveData( USART3 );
\r
245 xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
\r
248 /* If sending or receiving from a queue has caused a task to unblock, and
\r
249 the unblocked task has a priority equal to or higher than the currently
\r
250 running task (the task this ISR interrupted), then xHigherPriorityTaskWoken
\r
251 will have automatically been set to pdTRUE within the queue send or receive
\r
252 function. portEND_SWITCHING_ISR() will then ensure that this ISR returns
\r
253 directly to the higher priority unblocked task. */
\r
254 portEND_SWITCHING_ISR( xHigherPriorityTaskWoken );
\r