2 FreeRTOS.org V5.3.1 - Copyright (C) 2003-2009 Richard Barry.
\r
4 This file is part of the FreeRTOS.org distribution.
\r
6 FreeRTOS.org is free software; you can redistribute it and/or modify it
\r
7 under the terms of the GNU General Public License (version 2) as published
\r
8 by the Free Software Foundation and modified by the FreeRTOS exception.
\r
9 **NOTE** The exception to the GPL is included to allow you to distribute a
\r
10 combined work that includes FreeRTOS.org without being obliged to provide
\r
11 the source code for any proprietary components. Alternative commercial
\r
12 license and support terms are also available upon request. See the
\r
13 licensing section of http://www.FreeRTOS.org for full details.
\r
15 FreeRTOS.org is distributed in the hope that it will be useful, but WITHOUT
\r
16 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
\r
17 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
\r
20 You should have received a copy of the GNU General Public License along
\r
21 with FreeRTOS.org; if not, write to the Free Software Foundation, Inc., 59
\r
22 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
\r
25 ***************************************************************************
\r
27 * Get the FreeRTOS eBook! See http://www.FreeRTOS.org/Documentation *
\r
29 * This is a concise, step by step, 'hands on' guide that describes both *
\r
30 * general multitasking concepts and FreeRTOS specifics. It presents and *
\r
31 * explains numerous examples that are written using the FreeRTOS API. *
\r
32 * Full source code for all the examples is provided in an accompanying *
\r
35 ***************************************************************************
\r
39 Please ensure to read the configuration and relevant port sections of the
\r
40 online documentation.
\r
42 http://www.FreeRTOS.org - Documentation, latest information, license and
\r
45 http://www.SafeRTOS.com - A version that is certified for use in safety
\r
48 http://www.OpenRTOS.com - Commercial support, development, porting,
\r
49 licensing and training services.
\r
53 BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR UART0.
\r
55 *NOTE* - This file is designed to test some of the RTOS features - it is
\r
56 not intended to represent an efficient implementation!
\r
59 /* Standard includes. */
\r
62 /* Scheduler includes. */
\r
63 #include "FreeRTOS.h"
\r
66 /* Demo application includes. */
\r
70 /* Hardware specifics. */
\r
71 #define serRX_DATA_PIN ( 0x01 )
\r
72 #define serTX_DATA_PIN ( 0x02 )
\r
73 #define serCLOCK_Fxx_DIV_8 0x03
\r
74 #define serUPWR ( 0x80 )
\r
75 #define serUTXE ( 0x40 )
\r
76 #define serURXE ( 0x20 )
\r
77 #define serUCL ( 0x02 )
\r
78 #define serLSB ( 0x10 )
\r
81 #define serINVALID_QUEUE ( ( xQueueHandle ) 0 )
\r
82 #define serHANDLE ( ( xComPortHandle ) 1 )
\r
83 #define serNO_BLOCK ( ( portTickType ) 0 )
\r
85 /*-----------------------------------------------------------*/
\r
87 /* Queues used to hold received characters, and characters waiting to be
\r
89 static xQueueHandle xRxedChars;
\r
90 static xQueueHandle xCharsForTx;
\r
92 /*-----------------------------------------------------------*/
\r
94 /* Interrupt entry point written in the assembler file serialISR.s85. */
\r
95 extern void vSerialISREntry( void );
\r
97 /* Flag to indicate whether or not there are characters already queued to send. */
\r
98 static volatile unsigned long ulTxInProgress = pdFALSE;
\r
100 /*-----------------------------------------------------------*/
\r
103 * See the serial2.h header file.
\r
105 xComPortHandle xSerialPortInitMinimal( unsigned portLONG ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
\r
107 xComPortHandle xReturn = serHANDLE;
\r
108 const unsigned portLONG ulFuclk = ( configCPU_CLOCK_HZ / 2 ) / 8UL;
\r
110 /* Create the queues used to hold Rx and Tx characters. */
\r
111 xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
\r
112 xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
\r
114 /* If the queues were created correctly then setup the serial port
\r
116 if( ( xRxedChars != serINVALID_QUEUE ) && ( xCharsForTx != serINVALID_QUEUE ) )
\r
118 portENTER_CRITICAL();
\r
120 /* Set the UART0 Rx and Tx pins to their alternative function. */
\r
121 PMC3 |= ( serRX_DATA_PIN | serTX_DATA_PIN );
\r
122 PM3 &= ~( serTX_DATA_PIN );
\r
124 /* Setup clock for required baud. */
\r
125 UD0CTL1 = serCLOCK_Fxx_DIV_8;
\r
126 UD0CTL2 = ulFuclk / ( 2 * ulWantedBaud );
\r
128 /* Enable, n81. */
\r
129 UD0CTL0 = ( serUPWR | serUTXE | serURXE | serUCL | serLSB );
\r
131 /* Enable interrupts for both Rx and Tx. */
\r
135 ulTxInProgress = pdFALSE;
\r
137 portEXIT_CRITICAL();
\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 portCHAR *pcRxedChar, portTickType 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 portCHAR * const pcString, unsigned portSHORT usStringLength )
\r
170 signed portCHAR *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 UART0. */
\r
182 /* Send each character in the string, one at a time. */
\r
183 pxNext = ( signed portCHAR * ) pcString;
\r
186 xSerialPutChar( pxPort, *pxNext, serNO_BLOCK );
\r
190 /*-----------------------------------------------------------*/
\r
192 signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed portCHAR cOutChar, portTickType xBlockTime )
\r
194 portBASE_TYPE xReturn = pdPASS;
\r
196 portENTER_CRITICAL();
\r
198 /* There are currently no characters queued up to send so write the
\r
199 character directly to the UART. */
\r
200 if( ulTxInProgress == pdFALSE )
\r
203 ulTxInProgress = pdTRUE;
\r
207 /* The UART is already busy so write the character to the Tx queue.
\r
208 The queue is drained from within the Tx interrupt. */
\r
209 if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
\r
215 portEXIT_CRITICAL();
\r
219 /*-----------------------------------------------------------*/
\r
221 void vSerialClose( xComPortHandle xPort )
\r
223 /* Not supported as not required by the demo application. */
\r
225 /*-----------------------------------------------------------*/
\r
227 /* Tx interrupt handler. This is called from the asm file wrapper. */
\r
228 void vUARTTxISRHandler( void )
\r
231 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
\r
233 /* Are there any more characters queue to transmit? */
\r
234 if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )
\r
236 /* Send the next character. */
\r
241 /* The UART is no longer active. */
\r
242 ulTxInProgress = pdFALSE;
\r
245 /* If reading a character from the Rx queue caused a task to unblock, and
\r
246 the unblocked task has a priority higher than the currently running task,
\r
247 then xHigherPriorityTaskWoken will have been set to true and a context
\r
248 switch should occur now. */
\r
249 portYIELD_FROM_ISR( xHigherPriorityTaskWoken );
\r
251 /*-----------------------------------------------------------*/
\r
253 /* Rx interrupt handler. This is called from the asm file wrapper. */
\r
254 void vUARTRxISRHandler( void )
\r
257 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
\r
259 /* Send the received character to the Rx queue. */
\r
261 xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
\r
263 /* If sending a character to the Tx queue caused a task to unblock, and
\r
264 the unblocked task has a priority higher than the currently running task,
\r
265 then xHigherPriorityTaskWoken will have been set to true and a context
\r
266 switch should occur now. */
\r
267 portYIELD_FROM_ISR( xHigherPriorityTaskWoken );
\r