2 FreeRTOS V7.1.1 - 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
70 + The function xPortInitMinimal() has been renamed to
\r
71 xSerialPortInitMinimal() and the function xPortInit() has been renamed
\r
72 to xSerialPortInit().
\r
76 + Delay periods are now specified using variables and constants of
\r
77 portTickType rather than unsigned long.
\r
78 + xQueueReceiveFromISR() used in place of xQueueReceive() within the ISR.
\r
82 + Replaced the inb() and outb() functions with direct memory
\r
83 access. This allows the port to be built with the 20050414 build of
\r
87 /* BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER. */
\r
91 #include <avr/interrupt.h>
\r
92 #include "FreeRTOS.h"
\r
97 #define serBAUD_DIV_CONSTANT ( ( unsigned long ) 16 )
\r
99 /* Constants for writing to UCSRB. */
\r
100 #define serRX_INT_ENABLE ( ( unsigned char ) 0x80 )
\r
101 #define serRX_ENABLE ( ( unsigned char ) 0x10 )
\r
102 #define serTX_ENABLE ( ( unsigned char ) 0x08 )
\r
103 #define serTX_INT_ENABLE ( ( unsigned char ) 0x20 )
\r
105 /* Constants for writing to UCSRC. */
\r
106 #define serUCSRC_SELECT ( ( unsigned char ) 0x80 )
\r
107 #define serEIGHT_DATA_BITS ( ( unsigned char ) 0x06 )
\r
109 static xQueueHandle xRxedChars;
\r
110 static xQueueHandle xCharsForTx;
\r
112 #define vInterruptOn() \
\r
114 unsigned char ucByte; \
\r
117 ucByte |= serTX_INT_ENABLE; \
\r
120 /*-----------------------------------------------------------*/
\r
122 #define vInterruptOff() \
\r
124 unsigned char ucInByte; \
\r
126 ucInByte = UCSRB; \
\r
127 ucInByte &= ~serTX_INT_ENABLE; \
\r
128 UCSRB = ucInByte; \
\r
130 /*-----------------------------------------------------------*/
\r
132 xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
\r
134 unsigned long ulBaudRateCounter;
\r
135 unsigned char ucByte;
\r
137 portENTER_CRITICAL();
\r
139 /* Create the queues used by the com test task. */
\r
140 xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
\r
141 xCharsForTx = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
\r
143 /* Calculate the baud rate register value from the equation in the
\r
145 ulBaudRateCounter = ( configCPU_CLOCK_HZ / ( serBAUD_DIV_CONSTANT * ulWantedBaud ) ) - ( unsigned long ) 1;
\r
147 /* Set the baud rate. */
\r
148 ucByte = ( unsigned char ) ( ulBaudRateCounter & ( unsigned long ) 0xff );
\r
151 ulBaudRateCounter >>= ( unsigned long ) 8;
\r
152 ucByte = ( unsigned char ) ( ulBaudRateCounter & ( unsigned long ) 0xff );
\r
155 /* Enable the Rx interrupt. The Tx interrupt will get enabled
\r
156 later. Also enable the Rx and Tx. */
\r
157 UCSRB = ( serRX_INT_ENABLE | serRX_ENABLE | serTX_ENABLE );
\r
159 /* Set the data bits to 8. */
\r
160 UCSRC = ( serUCSRC_SELECT | serEIGHT_DATA_BITS );
\r
162 portEXIT_CRITICAL();
\r
164 /* Unlike other ports, this serial code does not allow for more than one
\r
165 com port. We therefore don't return a pointer to a port structure and can
\r
166 instead just return NULL. */
\r
169 /*-----------------------------------------------------------*/
\r
171 signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, portTickType xBlockTime )
\r
173 /* Only one port is supported. */
\r
176 /* Get the next character from the buffer. Return false if no characters
\r
177 are available, or arrive before xBlockTime expires. */
\r
178 if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
\r
187 /*-----------------------------------------------------------*/
\r
189 signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, portTickType xBlockTime )
\r
191 /* Only one port is supported. */
\r
194 /* Return false if after the block time there is no room on the Tx queue. */
\r
195 if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
\r
204 /*-----------------------------------------------------------*/
\r
206 void vSerialClose( xComPortHandle xPort )
\r
208 unsigned char ucByte;
\r
210 /* The parameter is not used. */
\r
213 /* Turn off the interrupts. We may also want to delete the queues and/or
\r
214 re-install the original ISR. */
\r
216 portENTER_CRITICAL();
\r
220 ucByte &= ~serRX_INT_ENABLE;
\r
223 portEXIT_CRITICAL();
\r
225 /*-----------------------------------------------------------*/
\r
227 SIGNAL( SIG_UART_RECV )
\r
230 signed portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
\r
232 /* Get the character and post it on the queue of Rxed characters.
\r
233 If the post causes a task to wake force a context switch as the woken task
\r
234 may have a higher priority than the task we have interrupted. */
\r
237 xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
\r
239 if( xHigherPriorityTaskWoken != pdFALSE )
\r
244 /*-----------------------------------------------------------*/
\r
246 SIGNAL( SIG_UART_DATA )
\r
248 signed char cChar, cTaskWoken;
\r
250 if( xQueueReceiveFromISR( xCharsForTx, &cChar, &cTaskWoken ) == pdTRUE )
\r
252 /* Send the next character queued for Tx. */
\r
257 /* Queue empty, nothing to send. */
\r