2 FreeRTOS.org V4.8.0 - Copyright (C) 2003-2008 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
\r
7 it under the terms of the GNU General Public License as published by
\r
8 the Free Software Foundation; either version 2 of the License, or
\r
9 (at your option) any later version.
\r
11 FreeRTOS.org is distributed in the hope that it will be useful,
\r
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
\r
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
\r
14 GNU General Public License for more details.
\r
16 You should have received a copy of the GNU General Public License
\r
17 along with FreeRTOS.org; if not, write to the Free Software
\r
18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
\r
20 A special exception to the GPL can be applied should you wish to distribute
\r
21 a combined work that includes FreeRTOS.org, without being obliged to provide
\r
22 the source code for any proprietary components. See the licensing section
\r
23 of http://www.FreeRTOS.org for full details of how and when the exception
\r
26 ***************************************************************************
\r
27 ***************************************************************************
\r
29 * SAVE TIME AND MONEY! Why not get us to quote to get FreeRTOS.org *
\r
30 * running on your hardware - or even write all or part of your application*
\r
31 * for you? See http://www.OpenRTOS.com for details. *
\r
33 ***************************************************************************
\r
34 ***************************************************************************
\r
36 Please ensure to read the configuration and relevant port sections of the
\r
37 online documentation.
\r
39 http://www.FreeRTOS.org - Documentation, latest information, license and
\r
42 http://www.SafeRTOS.com - A version that is certified for use in safety
\r
45 http://www.OpenRTOS.com - Commercial support, development, porting,
\r
46 licensing and training services.
\r
51 * BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER.
\r
53 * This file only supports UART 2
\r
56 /* Standard includes. */
\r
59 /* Scheduler includes. */
\r
60 #include "FreeRTOS.h"
\r
64 /* Demo application includes. */
\r
67 /* The queue used to hold received characters. */
\r
68 static xQueueHandle xRxedChars;
\r
70 /* The queue used to hold characters waiting transmission. */
\r
71 static xQueueHandle xCharsForTx;
\r
73 static volatile portSHORT sTHREEmpty;
\r
75 /*-----------------------------------------------------------*/
\r
77 xComPortHandle xSerialPortInitMinimal( unsigned portLONG ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
\r
79 portENTER_CRITICAL();
\r
81 /* Create the queues used by the com test task. */
\r
82 xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
\r
83 xCharsForTx = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
\r
85 /* Initialize UART asynchronous mode */
\r
86 BGR02 = configPER_CLOCK_HZ / ulWantedBaud;
\r
88 SCR02 = 0x17; /* 8N1 */
\r
89 SMR02 = 0x0d; /* enable SOT3, Reset, normal mode */
\r
90 SSR02 = 0x02; /* LSB first, enable receive interrupts */
\r
92 PFR20_D0 = 1; /* enable UART */
\r
93 PFR20_D1 = 1; /* enable UART */
\r
95 EPFR20_D1 = 0; /* enable UART */
\r
97 portEXIT_CRITICAL();
\r
99 /* Unlike other ports, this serial code does not allow for more than one
\r
100 com port. We therefore don't return a pointer to a port structure and can
\r
101 instead just return NULL. */
\r
104 /*-----------------------------------------------------------*/
\r
106 signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed portCHAR *pcRxedChar, portTickType xBlockTime )
\r
108 /* Get the next character from the buffer. Return false if no characters
\r
109 are available, or arrive before xBlockTime expires. */
\r
110 if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
\r
119 /*-----------------------------------------------------------*/
\r
121 signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed portCHAR cOutChar, portTickType xBlockTime )
\r
123 signed portBASE_TYPE xReturn;
\r
125 /* Transmit a character. */
\r
126 portENTER_CRITICAL();
\r
128 if( sTHREEmpty == pdTRUE )
\r
130 /* If sTHREEmpty is true then the UART Tx ISR has indicated that
\r
131 there are no characters queued to be transmitted - so we can
\r
132 write the character directly to the shift Tx register. */
\r
133 sTHREEmpty = pdFALSE;
\r
139 /* sTHREEmpty is false, so there are still characters waiting to be
\r
140 transmitted. We have to queue this character so it gets
\r
141 transmitted in turn. */
\r
143 /* Return false if after the block time there is no room on the Tx
\r
144 queue. It is ok to block inside a critical section as each task
\r
145 maintains it's own critical section status. */
\r
146 if (xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) == pdTRUE)
\r
156 if (pdPASS == xReturn)
\r
158 /* Turn on the Tx interrupt so the ISR will remove the character from the
\r
159 queue and send it. This does not need to be in a critical section as
\r
160 if the interrupt has already removed the character the next interrupt
\r
161 will simply turn off the Tx interrupt again. */
\r
166 portEXIT_CRITICAL();
\r
170 /*-----------------------------------------------------------*/
\r
173 * UART RX interrupt service routine.
\r
175 __interrupt void UART2_RxISR (void)
\r
177 signed portCHAR cChar;
\r
179 /* Get the character from the UART and post it on the queue of Rxed
\r
183 if( xQueueSendFromISR( xRxedChars, &cChar, pdFALSE ) )
\r
185 /*If the post causes a task to wake force a context switch
\r
186 as the woken task may have a higher priority than the task we have
\r
188 portYIELD_FROM_ISR();
\r
192 /*-----------------------------------------------------------*/
\r
195 * UART Tx interrupt service routine.
\r
197 __interrupt void UART2_TxISR (void)
\r
199 signed portCHAR cChar;
\r
200 signed portBASE_TYPE xTaskWoken;
\r
202 /* The previous character has been transmitted. See if there are any
\r
203 further characters waiting transmission. */
\r
204 if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xTaskWoken ) == pdTRUE )
\r
206 /* There was another character queued - transmit it now. */
\r
211 /* There were no other characters to transmit. */
\r
212 sTHREEmpty = pdTRUE;
\r
214 /* Disable transmit interrupts */
\r