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/*
FreeRTOS.org V5.1.2 - Copyright (C) 2003-2009 Richard Barry.
This file is part of the FreeRTOS.org distribution.
FreeRTOS.org is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
FreeRTOS.org is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with FreeRTOS.org; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
A special exception to the GPL can be applied should you wish to distribute
a combined work that includes FreeRTOS.org, without being obliged to provide
the source code for any proprietary components. See the licensing section
of http://www.FreeRTOS.org for full details of how and when the exception
can be applied.
***************************************************************************
***************************************************************************
* *
* Get the FreeRTOS eBook! See http://www.FreeRTOS.org/Documentation *
* *
* This is a concise, step by step, 'hands on' guide that describes both *
* general multitasking concepts and FreeRTOS specifics. It presents and *
* explains numerous examples that are written using the FreeRTOS API. *
* Full source code for all the examples is provided in an accompanying *
* .zip file. *
* *
***************************************************************************
***************************************************************************
Please ensure to read the configuration and relevant port sections of the
online documentation.
http://www.FreeRTOS.org - Documentation, latest information, license and
contact details.
http://www.SafeRTOS.com - A version that is certified for use in safety
critical systems.
http://www.OpenRTOS.com - Commercial support, development, porting,
licensing and training services.
*/
/* BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER for port 1.
Note that this driver is written to test the RTOS port and is not intended
to represent an optimised solution. */
/* Processor Expert generated includes. */
#include "com0.h"
/* Scheduler include files. */
#include "FreeRTOS.h"
#include "queue.h"
#include "task.h"
/* Demo application include files. */
#include "serial.h"
/* The queues used to communicate between the task code and the interrupt
service routines. */
static xQueueHandle xRxedChars;
static xQueueHandle xCharsForTx;
/* Interrupt identification bits. */
#define serOVERRUN_INTERRUPT ( 0x08 )
#define serRX_INTERRUPT ( 0x20 )
#define serTX_INTERRUPT ( 0x80 )
/*-----------------------------------------------------------*/
/*
* Initialise port for interrupt driven communications.
*/
xComPortHandle xSerialPortInitMinimal( unsigned portLONG ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
{
/* Hardware setup is performed by the Processor Expert generated code.
This function just creates the queues used to communicate between the
interrupt code and the task code - then sets the required baud rate. */
xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
xCharsForTx = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
COM0_SetBaudRateMode( ( portCHAR ) ulWantedBaud );
return NULL;
}
/*-----------------------------------------------------------*/
signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed portCHAR *pcRxedChar, portTickType xBlockTime )
{
/* Get the next character from the buffer queue. Return false if no characters
are available, or arrive before xBlockTime expires. */
if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
{
return pdTRUE;
}
else
{
return pdFALSE;
}
}
/*-----------------------------------------------------------*/
signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed portCHAR cOutChar, portTickType xBlockTime )
{
/* Place the character in the queue of characters to be transmitted. */
if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
{
return pdFAIL;
}
/* Turn on the Tx interrupt so the ISR will remove the character from the
queue and send it. This does not need to be in a critical section as
if the interrupt has already removed the character the next interrupt
will simply turn off the Tx interrupt again. */
SCI0CR2_SCTIE = 1;;
return pdPASS;
}
/*-----------------------------------------------------------*/
void vSerialClose( xComPortHandle xPort )
{
/* Not supported. */
( void ) xPort;
}
/*-----------------------------------------------------------*/
/*
* Interrupt service routine for the serial port. Must be in non-banked
* memory.
*/
#pragma CODE_SEG __NEAR_SEG NON_BANKED
__interrupt void vCOM0_ISR( void )
{
volatile unsigned portCHAR ucByte, ucStatus;
portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
/* What caused the interrupt? */
ucStatus = SCI0SR1;
if( ucStatus & serOVERRUN_INTERRUPT )
{
/* The interrupt was caused by an overrun. Clear the error by reading
the data register. */
ucByte = SCI0DRL;
}
if( ucStatus & serRX_INTERRUPT )
{
/* The interrupt was caused by a character being received.
Read the received byte. */
ucByte = SCI0DRL;
/* Post the character onto the queue of received characters - noting
whether or not this wakes a task. */
xQueueSendFromISR( xRxedChars, ( void * ) &ucByte, &xHigherPriorityTaskWoken );
}
if( ( ucStatus & serTX_INTERRUPT ) && ( SCI0CR2_SCTIE ) )
{
/* The interrupt was caused by a character being transmitted. */
if( xQueueReceiveFromISR( xCharsForTx, ( void * ) &ucByte, &xHigherPriorityTaskWoken ) == pdTRUE )
{
/* Clear the SCRF bit. */
SCI0DRL = ucByte;
}
else
{
/* Disable transmit interrupt */
SCI0CR2_SCTIE = 0;
}
}
if( xHigherPriorityTaskWoken )
{
portYIELD();
}
}
#pragma CODE_SEG DEFAULT
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