2 FreeRTOS V8.1.2 - Copyright (C) 2014 Real Time Engineers Ltd.
\r
5 VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
\r
7 ***************************************************************************
\r
9 * FreeRTOS provides completely free yet professionally developed, *
\r
10 * robust, strictly quality controlled, supported, and cross *
\r
11 * platform software that has become a de facto standard. *
\r
13 * Help yourself get started quickly and support the FreeRTOS *
\r
14 * project by purchasing a FreeRTOS tutorial book, reference *
\r
15 * manual, or both from: http://www.FreeRTOS.org/Documentation *
\r
19 ***************************************************************************
\r
21 This file is part of the FreeRTOS distribution.
\r
23 FreeRTOS is free software; you can redistribute it and/or modify it under
\r
24 the terms of the GNU General Public License (version 2) as published by the
\r
25 Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
\r
27 >>! NOTE: The modification to the GPL is included to allow you to !<<
\r
28 >>! distribute a combined work that includes FreeRTOS without being !<<
\r
29 >>! obliged to provide the source code for proprietary components !<<
\r
30 >>! outside of the FreeRTOS kernel. !<<
\r
32 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
\r
33 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
\r
34 FOR A PARTICULAR PURPOSE. Full license text is available from the following
\r
35 link: http://www.freertos.org/a00114.html
\r
39 ***************************************************************************
\r
41 * Having a problem? Start by reading the FAQ "My application does *
\r
42 * not run, what could be wrong?" *
\r
44 * http://www.FreeRTOS.org/FAQHelp.html *
\r
46 ***************************************************************************
\r
48 http://www.FreeRTOS.org - Documentation, books, training, latest versions,
\r
49 license and Real Time Engineers Ltd. contact details.
\r
51 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
\r
52 including FreeRTOS+Trace - an indispensable productivity tool, a DOS
\r
53 compatible FAT file system, and our tiny thread aware UDP/IP stack.
\r
55 http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
\r
56 Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
\r
57 licenses offer ticketed support, indemnification and middleware.
\r
59 http://www.SafeRTOS.com - High Integrity Systems also provide a safety
\r
60 engineered and independently SIL3 certified version for use in safety and
\r
61 mission critical applications that require provable dependability.
\r
67 BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR UART0.
\r
69 ***Note*** This example uses queues to send each character into an interrupt
\r
70 service routine and out of an interrupt service routine individually. This
\r
71 is done to demonstrate queues being used in an interrupt, and to deliberately
\r
72 load the system to test the FreeRTOS port. It is *NOT* meant to be an
\r
73 example of an efficient implementation. An efficient implementation should
\r
74 use FIFO's or DMA if available, and only use FreeRTOS API functions when
\r
75 enough has been received to warrant a task being unblocked to process the
\r
79 /* Scheduler includes. */
\r
80 #include "FreeRTOS.h"
\r
83 #include "comtest2.h"
\r
85 /* Library includes. */
\r
86 #include "stm32l152_eval.h"
\r
88 /* Demo application includes. */
\r
90 /*-----------------------------------------------------------*/
\r
93 #define serINVALID_QUEUE ( ( QueueHandle_t ) 0 )
\r
94 #define serNO_BLOCK ( ( TickType_t ) 0 )
\r
96 /*-----------------------------------------------------------*/
\r
98 /* The queue used to hold received characters. */
\r
99 static QueueHandle_t xRxedChars;
\r
100 static QueueHandle_t xCharsForTx;
\r
102 /*-----------------------------------------------------------*/
\r
105 * See the serial2.h header file.
\r
107 xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
\r
109 USART_InitTypeDef USART_InitStructure;
\r
110 xComPortHandle xReturn;
\r
111 NVIC_InitTypeDef NVIC_InitStructure;
\r
113 /* Create the queues used to hold Rx/Tx characters. */
\r
114 xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
\r
115 xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
\r
117 /* If the queues were created correctly then setup the serial port
\r
119 if( ( xRxedChars != serINVALID_QUEUE ) && ( xCharsForTx != serINVALID_QUEUE ) )
\r
121 USART_InitStructure.USART_BaudRate = ulWantedBaud;
\r
122 USART_InitStructure.USART_WordLength = USART_WordLength_8b;
\r
123 USART_InitStructure.USART_StopBits = USART_StopBits_1;
\r
124 USART_InitStructure.USART_Parity = USART_Parity_No;
\r
125 USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
\r
126 USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
\r
128 /* The Eval board COM2 is being used, which in reality is the STM32
\r
130 STM_EVAL_COMInit( COM2, &USART_InitStructure );
\r
132 NVIC_InitStructure.NVIC_IRQChannel = USART3_IRQn;
\r
133 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY;
\r
134 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; /* Not used as 4 bits are used for the pre-emption priority. */;
\r
135 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
\r
136 NVIC_Init( &NVIC_InitStructure );
\r
137 USART_ITConfig( USART3, USART_IT_RXNE, ENABLE );
\r
141 xReturn = ( xComPortHandle ) 0;
\r
144 /* This demo file only supports a single port but we have to return
\r
145 something to comply with the standard demo header file. */
\r
148 /*-----------------------------------------------------------*/
\r
150 signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, TickType_t xBlockTime )
\r
152 /* The port handle is not required as this driver only supports one port. */
\r
155 /* Get the next character from the buffer. Return false if no characters
\r
156 are available, or arrive before xBlockTime expires. */
\r
157 if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
\r
166 /*-----------------------------------------------------------*/
\r
168 void vSerialPutString( xComPortHandle pxPort, const signed char * const pcString, unsigned short usStringLength )
\r
170 signed char *pxNext;
\r
172 /* A couple of parameters that this port does not use. */
\r
173 ( void ) usStringLength;
\r
176 /* NOTE: This implementation does not handle the queue being full as no
\r
177 block time is used! */
\r
179 /* The port handle is not required as this driver only supports UART1. */
\r
182 /* Send each character in the string, one at a time. */
\r
183 pxNext = ( signed char * ) pcString;
\r
186 xSerialPutChar( pxPort, *pxNext, serNO_BLOCK );
\r
190 /*-----------------------------------------------------------*/
\r
192 signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, TickType_t xBlockTime )
\r
194 signed portBASE_TYPE xReturn;
\r
196 if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) == pdPASS )
\r
199 USART_ITConfig( USART3, USART_IT_TXE, ENABLE );
\r
208 /*-----------------------------------------------------------*/
\r
210 void vSerialClose( xComPortHandle xPort )
\r
212 /* Not supported as not required by the demo application. */
\r
214 /*-----------------------------------------------------------*/
\r
216 void USART3_IRQHandler( void )
\r
218 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
\r
221 if( USART_GetITStatus( USART3, USART_IT_TXE ) == SET )
\r
223 /* The interrupt was caused by the TX register becoming empty. Are
\r
224 there any more characters to transmit? */
\r
225 if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )
\r
227 /* A character was retrieved from the queue so can be sent to the
\r
229 USART_SendData( USART3, cChar );
\r
233 USART_ITConfig( USART3, USART_IT_TXE, DISABLE );
\r
237 if( USART_GetITStatus( USART3, USART_IT_RXNE ) == SET )
\r
239 /* A character has been received on the USART, send it to the Rx
\r
241 cChar = USART_ReceiveData( USART3 );
\r
242 xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
\r
245 /* If sending or receiving from a queue has caused a task to unblock, and
\r
246 the unblocked task has a priority equal to or higher than the currently
\r
247 running task (the task this ISR interrupted), then xHigherPriorityTaskWoken
\r
248 will have automatically been set to pdTRUE within the queue send or receive
\r
249 function. portEND_SWITCHING_ISR() will then ensure that this ISR returns
\r
250 directly to the higher priority unblocked task. */
\r
251 portEND_SWITCHING_ISR( xHigherPriorityTaskWoken );
\r