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 BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR UART0.
\r
70 *NOTE* - This file is designed to test some of the RTOS features - it is
\r
71 not intended to represent an efficient implementation!
\r
74 /* Standard includes. */
\r
77 /* Scheduler includes. */
\r
78 #include "FreeRTOS.h"
\r
81 /* Demo application includes. */
\r
85 /* Hardware specifics. */
\r
86 #define serRX_DATA_PIN ( 0x01 )
\r
87 #define serTX_DATA_PIN ( 0x02 )
\r
88 #define serCLOCK_Fxx_DIV_8 0x03
\r
89 #define serUPWR ( 0x80 )
\r
90 #define serUTXE ( 0x40 )
\r
91 #define serURXE ( 0x20 )
\r
92 #define serUCL ( 0x02 )
\r
93 #define serLSB ( 0x10 )
\r
96 #define serINVALID_QUEUE ( ( xQueueHandle ) 0 )
\r
97 #define serHANDLE ( ( xComPortHandle ) 1 )
\r
98 #define serNO_BLOCK ( ( portTickType ) 0 )
\r
100 /*-----------------------------------------------------------*/
\r
102 /* Queues used to hold received characters, and characters waiting to be
\r
104 static xQueueHandle xRxedChars;
\r
105 static xQueueHandle xCharsForTx;
\r
107 /*-----------------------------------------------------------*/
\r
109 /* Interrupt entry point written in the assembler file serialISR.s85. */
\r
110 extern void vSerialISREntry( void );
\r
112 /* Flag to indicate whether or not there are characters already queued to send. */
\r
113 static volatile unsigned long ulTxInProgress = pdFALSE;
\r
115 /*-----------------------------------------------------------*/
\r
118 * See the serial2.h header file.
\r
120 xComPortHandle xSerialPortInitMinimal( unsigned portLONG ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
\r
122 xComPortHandle xReturn = serHANDLE;
\r
123 const unsigned portLONG ulFuclk = ( configCPU_CLOCK_HZ / 2 ) / 8UL;
\r
125 /* Create the queues used to hold Rx and Tx characters. */
\r
126 xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
\r
127 xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
\r
129 /* If the queues were created correctly then setup the serial port
\r
131 if( ( xRxedChars != serINVALID_QUEUE ) && ( xCharsForTx != serINVALID_QUEUE ) )
\r
133 portENTER_CRITICAL();
\r
135 /* Set the UART0 Rx and Tx pins to their alternative function. */
\r
136 PMC3 |= ( serRX_DATA_PIN | serTX_DATA_PIN );
\r
137 PM3 &= ~( serTX_DATA_PIN );
\r
139 /* Setup clock for required baud. */
\r
140 UD0CTL1 = serCLOCK_Fxx_DIV_8;
\r
141 UD0CTL2 = ulFuclk / ( 2 * ulWantedBaud );
\r
143 /* Enable, n81. */
\r
144 UD0CTL0 = ( serUPWR | serUTXE | serURXE | serUCL | serLSB );
\r
146 /* Enable interrupts for both Rx and Tx. */
\r
150 ulTxInProgress = pdFALSE;
\r
152 portEXIT_CRITICAL();
\r
156 xReturn = ( xComPortHandle ) 0;
\r
159 /* This demo file only supports a single port but we have to return
\r
160 something to comply with the standard demo header file. */
\r
163 /*-----------------------------------------------------------*/
\r
165 signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed portCHAR *pcRxedChar, portTickType xBlockTime )
\r
167 /* The port handle is not required as this driver only supports one port. */
\r
170 /* Get the next character from the buffer. Return false if no characters
\r
171 are available, or arrive before xBlockTime expires. */
\r
172 if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
\r
181 /*-----------------------------------------------------------*/
\r
183 void vSerialPutString( xComPortHandle pxPort, const signed portCHAR * const pcString, unsigned portSHORT usStringLength )
\r
185 signed portCHAR *pxNext;
\r
187 /* A couple of parameters that this port does not use. */
\r
188 ( void ) usStringLength;
\r
191 /* NOTE: This implementation does not handle the queue being full as no
\r
192 block time is used! */
\r
194 /* The port handle is not required as this driver only supports UART0. */
\r
197 /* Send each character in the string, one at a time. */
\r
198 pxNext = ( signed portCHAR * ) pcString;
\r
201 xSerialPutChar( pxPort, *pxNext, serNO_BLOCK );
\r
205 /*-----------------------------------------------------------*/
\r
207 signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed portCHAR cOutChar, portTickType xBlockTime )
\r
209 portBASE_TYPE xReturn = pdPASS;
\r
211 portENTER_CRITICAL();
\r
213 /* There are currently no characters queued up to send so write the
\r
214 character directly to the UART. */
\r
215 if( ulTxInProgress == pdFALSE )
\r
218 ulTxInProgress = pdTRUE;
\r
222 /* The UART is already busy so write the character to the Tx queue.
\r
223 The queue is drained from within the Tx interrupt. */
\r
224 if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
\r
230 portEXIT_CRITICAL();
\r
234 /*-----------------------------------------------------------*/
\r
236 void vSerialClose( xComPortHandle xPort )
\r
238 /* Not supported as not required by the demo application. */
\r
240 /*-----------------------------------------------------------*/
\r
242 /* Tx interrupt handler. This is called from the asm file wrapper. */
\r
243 void vUARTTxISRHandler( void )
\r
246 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
\r
248 /* Are there any more characters queue to transmit? */
\r
249 if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )
\r
251 /* Send the next character. */
\r
256 /* The UART is no longer active. */
\r
257 ulTxInProgress = pdFALSE;
\r
260 /* If reading a character from the Rx queue caused a task to unblock, and
\r
261 the unblocked task has a priority higher than the currently running task,
\r
262 then xHigherPriorityTaskWoken will have been set to true and a context
\r
263 switch should occur now. */
\r
264 portYIELD_FROM_ISR( xHigherPriorityTaskWoken );
\r
266 /*-----------------------------------------------------------*/
\r
268 /* Rx interrupt handler. This is called from the asm file wrapper. */
\r
269 void vUARTRxISRHandler( void )
\r
272 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
\r
274 /* Send the received character to the Rx queue. */
\r
276 xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
\r
278 /* If sending a character to the Tx queue caused a task to unblock, and
\r
279 the unblocked task has a priority higher than the currently running task,
\r
280 then xHigherPriorityTaskWoken will have been set to true and a context
\r
281 switch should occur now. */
\r
282 portYIELD_FROM_ISR( xHigherPriorityTaskWoken );
\r