FreeRTOS/Demo/WizNET_DEMO_TERN_186/serial/serial.c - third_party/github/FreeRTOS/FreeRTOS-Kernel - Git at Google

 /*
     FreeRTOS V7.4.0 - Copyright (C) 2013 Real Time Engineers Ltd.

     FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME.  PLEASE VISIT
     http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.

     ***************************************************************************
      *                                                                       *
      *    FreeRTOS tutorial books are available in pdf and paperback.        *
      *    Complete, revised, and edited pdf reference manuals are also       *
      *    available.                                                         *
      *                                                                       *
      *    Purchasing FreeRTOS documentation will not only help you, by       *
      *    ensuring you get running as quickly as possible and with an        *
      *    in-depth knowledge of how to use FreeRTOS, it will also help       *
      *    the FreeRTOS project to continue with its mission of providing     *
      *    professional grade, cross platform, de facto standard solutions    *
      *    for microcontrollers - completely free of charge!                  *
      *                                                                       *
      *    >>> See http://www.FreeRTOS.org/Documentation for details. <<<     *
      *                                                                       *
      *    Thank you for using FreeRTOS, and thank you for your support!      *
      *                                                                       *
     ***************************************************************************


     This file is part of the FreeRTOS distribution.

     FreeRTOS is free software; you can redistribute it and/or modify it under
     the terms of the GNU General Public License (version 2) as published by the
     Free Software Foundation AND MODIFIED BY the FreeRTOS exception.

     >>>>>>NOTE<<<<<< The modification to the GPL is included to allow you to
     distribute a combined work that includes FreeRTOS without being obliged to
     provide the source code for proprietary components outside of the FreeRTOS
     kernel.

     FreeRTOS 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
     and the FreeRTOS license exception along with FreeRTOS; if not itcan be
     viewed here: http://www.freertos.org/a00114.html and also obtained by
     writing to Real Time Engineers Ltd., contact details for whom are available
     on the FreeRTOS WEB site.

     1 tab == 4 spaces!

     ***************************************************************************
      *                                                                       *
      *    Having a problem?  Start by reading the FAQ "My application does   *
      *    not run, what could be wrong?"                                     *
      *                                                                       *
      *    http://www.FreeRTOS.org/FAQHelp.html                               *
      *                                                                       *
     ***************************************************************************


     http://www.FreeRTOS.org - Documentation, books, training, latest versions,
     license and Real Time Engineers Ltd. contact details.

     http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
     including FreeRTOS+Trace - an indispensable productivity tool, and our new
     fully thread aware and reentrant UDP/IP stack.

     http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
     Integrity Systems, who sell the code with commercial support,
     indemnification and middleware, under the OpenRTOS brand.

     http://www.SafeRTOS.com - High Integrity Systems also provide a safety
     engineered and independently SIL3 certified version for use in safety and
     mission critical applications that require provable dependability.
 */


 #include <stdlib.h>
 #include <embedded.h>
 #include "FreeRTOS.h"
 #include "portasm.h"
 #include "queue.h"
 #include "task.h"
 #include "semphr.h"

 #define serMAX_PORTS			( ( unsigned short ) 2 )

 #define serPORT_0_INT_REG		( 0xff44 )
 #define serPORT_0_BAUD_REG		( 0xff88 )
 #define serPORT_0_RX_REG		( 0xff86 )
 #define serPORT_0_TX_REG		( 0xff84 )
 #define serPORT_0_STATUS_REG	( 0xff82 )
 #define serPORT_0_CTRL_REG		( 0xff80 )
 #define serPORT_0_IRQ			( 0x14 )

 #define serPORT_1_INT_REG		( 0xff42 )
 #define serPORT_1_BAUD_REG		( 0xff18 )
 #define serPORT_1_RX_REG		( 0xff16 )
 #define serPORT_1_TX_REG		( 0xff14 )
 #define serPORT_1_STATUS_REG	( 0xff12 )
 #define serPORT_1_CTRL_REG		( 0xff10 )
 #define serPORT_1_IRQ			( 0x11 )

 #define serTX_EMPTY				( ( unsigned short ) 0x40 )
 #define serRX_READY				( ( unsigned short ) 0x80 )

 #define serRESET_PIC( usEOI_TYPE )	portOUTPUT_WORD( ( unsigned short ) 0xff22, usEOI_TYPE )
 #define serTX_HOLD_EMPTY_INT		( ( unsigned short ) 0x100 )

 #define serENABLE_INTERRUPTS		( ( unsigned short ) 0x80 )
 #define serMODE						( ( unsigned short ) 0x01 )
 #define serENABLE_TX_MACHINES		( ( unsigned short ) 0x40 )
 #define serENABLE_RX_MACHINES		( ( unsigned short ) 0x20 )
 #define serINTERRUPT_MASK			( ( unsigned short ) 0x08 )
 #define serCLEAR_ALL_STATUS_BITS	( ( unsigned short ) 0x00 )
 #define serINTERRUPT_PRIORITY		( ( unsigned short ) 0x01 ) /*< Just below the scheduler priority. */

 #define serDONT_BLOCK				( ( portTickType ) 0 )

 typedef enum
 {
 	serCOM1 = 0,
 	serCOM2,
 	serCOM3,
 	serCOM4,
 	serCOM5,
 	serCOM6,
 	serCOM7,
 	serCOM8
 } eCOMPort;

 typedef enum
 {
 	serNO_PARITY,
 	serODD_PARITY,
 	serEVEN_PARITY,
 	serMARK_PARITY,
 	serSPACE_PARITY
 } eParity;

 typedef enum
 {
 	serSTOP_1,
 	serSTOP_2
 } eStopBits;

 typedef enum
 {
 	serBITS_5,
 	serBITS_6,
 	serBITS_7,
 	serBITS_8
 } eDataBits;

 typedef enum
 {
 	ser50 = 0,
 	ser75,
 	ser110,
 	ser134,
 	ser150,
 	ser200,
 	ser300,
 	ser600,
 	ser1200,
 	ser1800,
 	ser2400,
 	ser4800,
 	ser9600,
 	ser19200,
 	ser38400,
 	ser57600,
 	ser115200
 } eBaud;

 typedef struct xCOM_PORT
 {
 	/* Hardware parameters for this port. */
 	short sTxInterruptOn;
 	unsigned short usIntReg;
 	unsigned short usBaudReg;
 	unsigned short usRxReg;
 	unsigned short usTxReg;
 	unsigned short usStatusReg;
 	unsigned short usCtrlReg;

 	unsigned short usIRQVector;

 	/* Queues used for communications with com test task. */
 	xQueueHandle xRxedChars;
 	xQueueHandle xCharsForTx;

 	/* This semaphore does nothing useful except test a feature of the
 	scheduler. */
 	xSemaphoreHandle xTestSem;

 } xComPort;

 static xComPort xPorts[ serMAX_PORTS ] =
 {
 	{ pdFALSE, serPORT_0_INT_REG, serPORT_0_BAUD_REG, serPORT_0_RX_REG, serPORT_0_TX_REG, serPORT_0_STATUS_REG, serPORT_0_CTRL_REG, serPORT_0_IRQ, NULL, NULL, NULL },
 	{ pdFALSE, serPORT_1_INT_REG, serPORT_1_BAUD_REG, serPORT_1_RX_REG, serPORT_1_TX_REG, serPORT_1_STATUS_REG, serPORT_1_CTRL_REG, serPORT_1_IRQ, NULL, NULL, NULL }
 };

 typedef xComPort * xComPortHandle;

 /**
  * Lookup the baud rate from the enum.
  */
 static unsigned long prvBaud( eBaud eWantedBaud );

 /* These prototypes are repeated here so we don't have to include the serial header.  This allows
 the xComPortHandle structure details to be private to this file. */
 xComPortHandle xSerialPortInit( eCOMPort ePort, eBaud eWantedBaud, eParity eWantedParity, eDataBits eWantedDataBits, eStopBits eWantedStopBits, unsigned portBASE_TYPE uxBufferLength );
 portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, char *pcRxedChar, portTickType xBlockTime );
 portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, char cOutChar, portTickType xBlockTime );
 void vSerialClose( xComPortHandle xPort );
 short sSerialWaitForSemaphore( xComPortHandle xPort );
 /*-----------------------------------------------------------*/

 static short xComPortISR( xComPort * const pxPort );

 #define vInterruptOn( pxPort, usInterrupt )										\
 {																				\
 unsigned short usIn;														\
 																				\
 	portENTER_CRITICAL();														\
 	{																			\
 		if( pxPort->sTxInterruptOn == pdFALSE )									\
 		{																		\
 			usIn = portINPUT_WORD( pxPort->usCtrlReg );							\
 			portOUTPUT_WORD( pxPort->usCtrlReg, usIn | usInterrupt );			\
 																				\
 			pxPort->sTxInterruptOn = pdTRUE;									\
 		}																		\
 	}																			\
 	portEXIT_CRITICAL();														\
 }
 /*-----------------------------------------------------------*/

 #define vInterruptOff( pxPort, usInterrupt )									\
 {																				\
 	unsigned short usIn = portINPUT_WORD( pxPort->usCtrlReg );				\
 	if( usIn & usInterrupt )													\
 	{																			\
 		portOUTPUT_WORD( pxPort->usCtrlReg, usIn & ~usInterrupt);				\
 		pxPort->sTxInterruptOn = pdFALSE;										\
 	}																			\
 }
 /*-----------------------------------------------------------*/


 /* Define an interrupt handler for each port */
 #define COM_IRQ_WRAPPER(N)										\
 	static void __interrupt COM_IRQ##N##_WRAPPER( void )		\
 	{															\
         if( xComPortISR( &( xPorts[##N##] ) ) )                 \
         {                                                       \
 			portEND_SWITCHING_ISR();                            \
 		}                                                       \
 	}


 COM_IRQ_WRAPPER( 0 )
 COM_IRQ_WRAPPER( 1 )

 static pxISR xISRs[ serMAX_PORTS ] =
 {
 	COM_IRQ0_WRAPPER,
 	COM_IRQ1_WRAPPER
 };

 /*-----------------------------------------------------------*/

 static unsigned long prvBaud( eBaud eWantedBaud )
 {
 	switch( eWantedBaud )
     {
 		case ser50			:	return 50UL;
 		case ser75			:	return 75UL;
 		case ser110			:	return 110UL;
 		case ser134			:	return 134UL;
 		case ser150			:	return 150UL;
 		case ser200			:	return 200UL;
 		case ser300			:	return 300UL;
 		case ser600			:	return 600UL;
 		case ser1200		:	return 1200UL;
 		case ser1800		:	return 1800UL;
 		case ser2400		:	return 2400UL;
 		case ser4800		:	return 4800UL;
 		case ser19200		:	return 19200UL;
 		case ser38400		:	return 38400UL;
 		case ser57600		:	return 57600UL;
 		case ser115200		:	return 115200UL;
 		default				:	return 9600UL;
     }
 }

 /*-----------------------------------------------------------*/

 xComPortHandle xSerialPortInit( eCOMPort ePort, eBaud eWantedBaud, eParity eWantedParity, eDataBits eWantedDataBits, eStopBits eWantedStopBits, unsigned portBASE_TYPE uxBufferLength )
 {
 unsigned short usPort;
 xComPortHandle pxPort = NULL;
 unsigned long ulBaudDiv;

 	/* BAUDDIV = ( Microprocessor Clock / Baud Rate ) / 16 */
     ulBaudDiv = ( configCPU_CLOCK_HZ / prvBaud( eWantedBaud ) ) / 16UL;

 	/* Only n, 8, 1 is supported so these parameters are not required for this
 	port. */
 	( void ) eWantedParity;
 	( void ) eWantedDataBits;
     ( void ) eWantedStopBits;

 	/* Currently only n,8,1 is supported. */

 	usPort = ( unsigned short ) ePort;

 	if( usPort < serMAX_PORTS )
 	{
 		pxPort = &( xPorts[ usPort ] );

 		portENTER_CRITICAL();
 		{
 			unsigned short usInWord;

 			/* Create the queues used by the com test task. */
 			pxPort->xRxedChars = xQueueCreate( uxBufferLength, ( unsigned portBASE_TYPE ) sizeof( char ) );
 			pxPort->xCharsForTx = xQueueCreate( uxBufferLength, ( unsigned portBASE_TYPE ) sizeof( char ) );

 			/* Create the test semaphore.  This does nothing useful except test a feature of the scheduler. */
 			vSemaphoreCreateBinary( pxPort->xTestSem );

 			/* There is no ISR here already to restore later. */
 			setvect( ( short ) pxPort->usIRQVector, xISRs[ usPort ] );

 			usInWord = portINPUT_WORD( pxPort->usIntReg );
 			usInWord &= ~serINTERRUPT_MASK;
 			usInWord |= serINTERRUPT_PRIORITY;
 			portOUTPUT_WORD( pxPort->usIntReg, usInWord );

 			portOUTPUT_WORD( pxPort->usBaudReg, ( unsigned short ) ulBaudDiv );
 			portOUTPUT_WORD( pxPort->usCtrlReg, serENABLE_INTERRUPTS | serMODE | serENABLE_TX_MACHINES | serENABLE_RX_MACHINES );

 			portOUTPUT_WORD( pxPort->usStatusReg, serCLEAR_ALL_STATUS_BITS );
 		}
 		portEXIT_CRITICAL();
 	}

 	return pxPort;
 } /*lint !e715 Some parameters are not used as only a subset of the serial port functionality is currently implemented. */
 /*-----------------------------------------------------------*/

 void vSerialPutString( xComPortHandle pxPort, const char * const pcString, unsigned short usStringLength )
 {
 unsigned short usByte;
 char *pcNextChar;

 	pcNextChar = ( char * ) pcString;

 	for( usByte = 0; usByte < usStringLength; usByte++ )
 	{
 		xQueueSend( pxPort->xCharsForTx, pcNextChar, serDONT_BLOCK );
 		pcNextChar++;
 	}

 	vInterruptOn( pxPort, serTX_HOLD_EMPTY_INT );
 }
 /*-----------------------------------------------------------*/

 portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, char *pcRxedChar, portTickType xBlockTime )
 {
 	/* Get the next character from the buffer, note that this routine is only
 	called having checked that the is (at least) one to get */
 	if( xQueueReceive( pxPort->xRxedChars, pcRxedChar, xBlockTime ) )
 	{
 		return pdTRUE;
 	}
 	else
 	{
 		return pdFALSE;
 	}
 }
 /*-----------------------------------------------------------*/

 portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, char cOutChar, portTickType xBlockTime )
 {
 	if( xQueueSend( pxPort->xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
 	{
 		return pdFAIL;
 	}

 	vInterruptOn( pxPort, serTX_HOLD_EMPTY_INT );

 	return pdPASS;
 }
 /*-----------------------------------------------------------*/

 portBASE_TYPE xSerialWaitForSemaphore( xComPortHandle xPort )
 {
 const portTickType xBlockTime = ( portTickType ) 0xffff;

 	/* This function does nothing interesting, but test the
 	semaphore from ISR mechanism. */
 	return xSemaphoreTake( xPort->xTestSem, xBlockTime );
 }
 /*-----------------------------------------------------------*/

 void vSerialClose( xComPortHandle xPort )
 {
 unsigned short usOutput;

 	/* Turn off the interrupts.  We may also want to delete the queues and/or
 	re-install the original ISR. */

 	portENTER_CRITICAL();
 	{
 		usOutput = portINPUT_WORD( xPort->usCtrlReg );

 		usOutput &= ~serENABLE_INTERRUPTS;
 		usOutput &= ~serENABLE_TX_MACHINES;
 		usOutput &= ~serENABLE_RX_MACHINES;
 		portOUTPUT_WORD( xPort->usCtrlReg, usOutput );

 		usOutput = portINPUT_WORD( xPort->usIntReg );
 		usOutput |= serINTERRUPT_MASK;
 		portOUTPUT_WORD( xPort->usIntReg, usOutput );
 	}
 	portEXIT_CRITICAL();
 }
 /*-----------------------------------------------------------*/
 unsigned short usStatus;
 static portBASE_TYPE xComPortISR( xComPort * const pxPort )
 {
 unsigned short usStatusRegister;
 char cChar;
 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;

 	/* NOTE:  THIS IS NOT AN EFFICIENT ISR AS IT IS DESIGNED SOLELY TO TEST
 	THE SCHEDULER FUNCTIONALITY.  REAL APPLICATIONS SHOULD NOT USE THIS
 	FUNCTION. */

 	usStatusRegister = portINPUT_WORD( pxPort->usStatusReg );

 	if( usStatusRegister & serRX_READY )
 	{
 		cChar = ( char ) portINPUT_WORD( pxPort->usRxReg );
 		xQueueSendFromISR( pxPort->xRxedChars, &cChar, &xHigherPriorityTaskWoken );

 		/* Also release the semaphore - this does nothing interesting and is just a test. */
 		xSemaphoreGiveFromISR( pxPort->xTestSem, &xHigherPriorityTaskWoken );
 	}
 	else if( pxPort->sTxInterruptOn && ( usStatusRegister & serTX_EMPTY ) )
 	{
 		if( xQueueReceiveFromISR( pxPort->xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )
 		{
 			portOUTPUT_WORD( pxPort->usTxReg, ( unsigned short ) cChar );
 		}
 		else
 		{
 			/* Queue empty, nothing to send */
 			vInterruptOff( pxPort, serTX_HOLD_EMPTY_INT );
 		}
 	}

     serRESET_PIC( pxPort->usIRQVector );

 	/* If posting to the queue woke a task that was blocked on the queue we may
 	want to switch to the woken task - depending on its priority relative to
 	the task interrupted by this ISR. */
 	return xHigherPriorityTaskWoken;
 }
	/*
	FreeRTOS V7.4.0 - Copyright (C) 2013 Real Time Engineers Ltd.

	FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME. PLEASE VISIT
	http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.

	***************************************************************************
	* *
	* FreeRTOS tutorial books are available in pdf and paperback. *
	* Complete, revised, and edited pdf reference manuals are also *
	* available. *
	* *
	* Purchasing FreeRTOS documentation will not only help you, by *
	* ensuring you get running as quickly as possible and with an *
	* in-depth knowledge of how to use FreeRTOS, it will also help *
	* the FreeRTOS project to continue with its mission of providing *
	* professional grade, cross platform, de facto standard solutions *
	* for microcontrollers - completely free of charge! *
	* *
	* >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
	* *
	* Thank you for using FreeRTOS, and thank you for your support! *
	* *
	***************************************************************************


	This file is part of the FreeRTOS distribution.

	FreeRTOS is free software; you can redistribute it and/or modify it under
	the terms of the GNU General Public License (version 2) as published by the
	Free Software Foundation AND MODIFIED BY the FreeRTOS exception.

	>>>>>>NOTE<<<<<< The modification to the GPL is included to allow you to
	distribute a combined work that includes FreeRTOS without being obliged to
	provide the source code for proprietary components outside of the FreeRTOS
	kernel.

	FreeRTOS 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
	and the FreeRTOS license exception along with FreeRTOS; if not itcan be
	viewed here: http://www.freertos.org/a00114.html and also obtained by
	writing to Real Time Engineers Ltd., contact details for whom are available
	on the FreeRTOS WEB site.

	1 tab == 4 spaces!

	***************************************************************************
	* *
	* Having a problem? Start by reading the FAQ "My application does *
	* not run, what could be wrong?" *
	* *
	* http://www.FreeRTOS.org/FAQHelp.html *
	* *
	***************************************************************************


	http://www.FreeRTOS.org - Documentation, books, training, latest versions,
	license and Real Time Engineers Ltd. contact details.

	http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
	including FreeRTOS+Trace - an indispensable productivity tool, and our new
	fully thread aware and reentrant UDP/IP stack.

	http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
	Integrity Systems, who sell the code with commercial support,
	indemnification and middleware, under the OpenRTOS brand.

	http://www.SafeRTOS.com - High Integrity Systems also provide a safety
	engineered and independently SIL3 certified version for use in safety and
	mission critical applications that require provable dependability.
	*/


	#include <stdlib.h>
	#include <embedded.h>
	#include "FreeRTOS.h"
	#include "portasm.h"
	#include "queue.h"
	#include "task.h"
	#include "semphr.h"

	#define serMAX_PORTS ( ( unsigned short ) 2 )

	#define serPORT_0_INT_REG ( 0xff44 )
	#define serPORT_0_BAUD_REG ( 0xff88 )
	#define serPORT_0_RX_REG ( 0xff86 )
	#define serPORT_0_TX_REG ( 0xff84 )
	#define serPORT_0_STATUS_REG ( 0xff82 )
	#define serPORT_0_CTRL_REG ( 0xff80 )
	#define serPORT_0_IRQ ( 0x14 )

	#define serPORT_1_INT_REG ( 0xff42 )
	#define serPORT_1_BAUD_REG ( 0xff18 )
	#define serPORT_1_RX_REG ( 0xff16 )
	#define serPORT_1_TX_REG ( 0xff14 )
	#define serPORT_1_STATUS_REG ( 0xff12 )
	#define serPORT_1_CTRL_REG ( 0xff10 )
	#define serPORT_1_IRQ ( 0x11 )

	#define serTX_EMPTY ( ( unsigned short ) 0x40 )
	#define serRX_READY ( ( unsigned short ) 0x80 )

	#define serRESET_PIC( usEOI_TYPE ) portOUTPUT_WORD( ( unsigned short ) 0xff22, usEOI_TYPE )
	#define serTX_HOLD_EMPTY_INT ( ( unsigned short ) 0x100 )

	#define serENABLE_INTERRUPTS ( ( unsigned short ) 0x80 )
	#define serMODE ( ( unsigned short ) 0x01 )
	#define serENABLE_TX_MACHINES ( ( unsigned short ) 0x40 )
	#define serENABLE_RX_MACHINES ( ( unsigned short ) 0x20 )
	#define serINTERRUPT_MASK ( ( unsigned short ) 0x08 )
	#define serCLEAR_ALL_STATUS_BITS ( ( unsigned short ) 0x00 )
	#define serINTERRUPT_PRIORITY ( ( unsigned short ) 0x01 ) /< Just below the scheduler priority. /

	#define serDONT_BLOCK ( ( portTickType ) 0 )

	typedef enum
	{
	serCOM1 = 0,
	serCOM2,
	serCOM3,
	serCOM4,
	serCOM5,
	serCOM6,
	serCOM7,
	serCOM8
	} eCOMPort;

	typedef enum
	{
	serNO_PARITY,
	serODD_PARITY,
	serEVEN_PARITY,
	serMARK_PARITY,
	serSPACE_PARITY
	} eParity;

	typedef enum
	{
	serSTOP_1,
	serSTOP_2
	} eStopBits;

	typedef enum
	{
	serBITS_5,
	serBITS_6,
	serBITS_7,
	serBITS_8
	} eDataBits;

	typedef enum
	{
	ser50 = 0,
	ser75,
	ser110,
	ser134,
	ser150,
	ser200,
	ser300,
	ser600,
	ser1200,
	ser1800,
	ser2400,
	ser4800,
	ser9600,
	ser19200,
	ser38400,
	ser57600,
	ser115200
	} eBaud;

	typedef struct xCOM_PORT
	{
	/* Hardware parameters for this port. */
	short sTxInterruptOn;
	unsigned short usIntReg;
	unsigned short usBaudReg;
	unsigned short usRxReg;
	unsigned short usTxReg;
	unsigned short usStatusReg;
	unsigned short usCtrlReg;

	unsigned short usIRQVector;

	/* Queues used for communications with com test task. */
	xQueueHandle xRxedChars;
	xQueueHandle xCharsForTx;

	/* This semaphore does nothing useful except test a feature of the
	scheduler. */
	xSemaphoreHandle xTestSem;

	} xComPort;

	static xComPort xPorts[ serMAX_PORTS ] =
	{
	{ pdFALSE, serPORT_0_INT_REG, serPORT_0_BAUD_REG, serPORT_0_RX_REG, serPORT_0_TX_REG, serPORT_0_STATUS_REG, serPORT_0_CTRL_REG, serPORT_0_IRQ, NULL, NULL, NULL },
	{ pdFALSE, serPORT_1_INT_REG, serPORT_1_BAUD_REG, serPORT_1_RX_REG, serPORT_1_TX_REG, serPORT_1_STATUS_REG, serPORT_1_CTRL_REG, serPORT_1_IRQ, NULL, NULL, NULL }
	};

	typedef xComPort * xComPortHandle;

	/**
	* Lookup the baud rate from the enum.
	*/
	static unsigned long prvBaud( eBaud eWantedBaud );

	/* These prototypes are repeated here so we don't have to include the serial header. This allows
	the xComPortHandle structure details to be private to this file. */
	xComPortHandle xSerialPortInit( eCOMPort ePort, eBaud eWantedBaud, eParity eWantedParity, eDataBits eWantedDataBits, eStopBits eWantedStopBits, unsigned portBASE_TYPE uxBufferLength );
	portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, char *pcRxedChar, portTickType xBlockTime );
	portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, char cOutChar, portTickType xBlockTime );
	void vSerialClose( xComPortHandle xPort );
	short sSerialWaitForSemaphore( xComPortHandle xPort );
	/-----------------------------------------------------------/

	static short xComPortISR( xComPort * const pxPort );

	#define vInterruptOn( pxPort, usInterrupt ) \
	{ \
	unsigned short usIn; \
	\
	portENTER_CRITICAL(); \
	{ \
	if( pxPort->sTxInterruptOn == pdFALSE ) \
	{ \
	usIn = portINPUT_WORD( pxPort->usCtrlReg ); \
	portOUTPUT_WORD( pxPort->usCtrlReg, usIn \| usInterrupt ); \
	\
	pxPort->sTxInterruptOn = pdTRUE; \
	} \
	} \
	portEXIT_CRITICAL(); \
	}
	/-----------------------------------------------------------/

	#define vInterruptOff( pxPort, usInterrupt ) \
	{ \
	unsigned short usIn = portINPUT_WORD( pxPort->usCtrlReg ); \
	if( usIn & usInterrupt ) \
	{ \
	portOUTPUT_WORD( pxPort->usCtrlReg, usIn & ~usInterrupt); \
	pxPort->sTxInterruptOn = pdFALSE; \
	} \
	}
	/-----------------------------------------------------------/


	/* Define an interrupt handler for each port */
	#define COM_IRQ_WRAPPER(N) \
	static void __interrupt COM_IRQ##N##_WRAPPER( void ) \
	{ \
	if( xComPortISR( &( xPorts[##N##] ) ) ) \
	{ \
	portEND_SWITCHING_ISR(); \
	} \
	}



	COM_IRQ_WRAPPER( 0 )
	COM_IRQ_WRAPPER( 1 )

	static pxISR xISRs[ serMAX_PORTS ] =
	{
	COM_IRQ0_WRAPPER,
	COM_IRQ1_WRAPPER
	};

	/-----------------------------------------------------------/

	static unsigned long prvBaud( eBaud eWantedBaud )
	{
	switch( eWantedBaud )
	{
	case ser50 : return 50UL;
	case ser75 : return 75UL;
	case ser110 : return 110UL;
	case ser134 : return 134UL;
	case ser150 : return 150UL;
	case ser200 : return 200UL;
	case ser300 : return 300UL;
	case ser600 : return 600UL;
	case ser1200 : return 1200UL;
	case ser1800 : return 1800UL;
	case ser2400 : return 2400UL;
	case ser4800 : return 4800UL;
	case ser19200 : return 19200UL;
	case ser38400 : return 38400UL;
	case ser57600 : return 57600UL;
	case ser115200 : return 115200UL;
	default : return 9600UL;
	}
	}

	/-----------------------------------------------------------/

	xComPortHandle xSerialPortInit( eCOMPort ePort, eBaud eWantedBaud, eParity eWantedParity, eDataBits eWantedDataBits, eStopBits eWantedStopBits, unsigned portBASE_TYPE uxBufferLength )
	{
	unsigned short usPort;
	xComPortHandle pxPort = NULL;
	unsigned long ulBaudDiv;

	/* BAUDDIV = ( Microprocessor Clock / Baud Rate ) / 16 */
	ulBaudDiv = ( configCPU_CLOCK_HZ / prvBaud( eWantedBaud ) ) / 16UL;

	/* Only n, 8, 1 is supported so these parameters are not required for this
	port. */
	( void ) eWantedParity;
	( void ) eWantedDataBits;
	( void ) eWantedStopBits;

	/* Currently only n,8,1 is supported. */

	usPort = ( unsigned short ) ePort;

	if( usPort < serMAX_PORTS )
	{
	pxPort = &( xPorts[ usPort ] );

	portENTER_CRITICAL();
	{
	unsigned short usInWord;

	/* Create the queues used by the com test task. */
	pxPort->xRxedChars = xQueueCreate( uxBufferLength, ( unsigned portBASE_TYPE ) sizeof( char ) );
	pxPort->xCharsForTx = xQueueCreate( uxBufferLength, ( unsigned portBASE_TYPE ) sizeof( char ) );

	/* Create the test semaphore. This does nothing useful except test a feature of the scheduler. */
	vSemaphoreCreateBinary( pxPort->xTestSem );

	/* There is no ISR here already to restore later. */
	setvect( ( short ) pxPort->usIRQVector, xISRs[ usPort ] );

	usInWord = portINPUT_WORD( pxPort->usIntReg );
	usInWord &= ~serINTERRUPT_MASK;
	usInWord \|= serINTERRUPT_PRIORITY;
	portOUTPUT_WORD( pxPort->usIntReg, usInWord );

	portOUTPUT_WORD( pxPort->usBaudReg, ( unsigned short ) ulBaudDiv );
	portOUTPUT_WORD( pxPort->usCtrlReg, serENABLE_INTERRUPTS \| serMODE \| serENABLE_TX_MACHINES \| serENABLE_RX_MACHINES );

	portOUTPUT_WORD( pxPort->usStatusReg, serCLEAR_ALL_STATUS_BITS );
	}
	portEXIT_CRITICAL();
	}

	return pxPort;
	} /lint !e715 Some parameters are not used as only a subset of the serial port functionality is currently implemented. /
	/-----------------------------------------------------------/

	void vSerialPutString( xComPortHandle pxPort, const char * const pcString, unsigned short usStringLength )
	{
	unsigned short usByte;
	char *pcNextChar;

	pcNextChar = ( char * ) pcString;

	for( usByte = 0; usByte < usStringLength; usByte++ )
	{
	xQueueSend( pxPort->xCharsForTx, pcNextChar, serDONT_BLOCK );
	pcNextChar++;
	}

	vInterruptOn( pxPort, serTX_HOLD_EMPTY_INT );
	}
	/-----------------------------------------------------------/

	portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, char *pcRxedChar, portTickType xBlockTime )
	{
	/* Get the next character from the buffer, note that this routine is only
	called having checked that the is (at least) one to get */
	if( xQueueReceive( pxPort->xRxedChars, pcRxedChar, xBlockTime ) )
	{
	return pdTRUE;
	}
	else
	{
	return pdFALSE;
	}
	}
	/-----------------------------------------------------------/

	portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, char cOutChar, portTickType xBlockTime )
	{
	if( xQueueSend( pxPort->xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
	{
	return pdFAIL;
	}

	vInterruptOn( pxPort, serTX_HOLD_EMPTY_INT );

	return pdPASS;
	}
	/-----------------------------------------------------------/

	portBASE_TYPE xSerialWaitForSemaphore( xComPortHandle xPort )
	{
	const portTickType xBlockTime = ( portTickType ) 0xffff;

	/* This function does nothing interesting, but test the
	semaphore from ISR mechanism. */
	return xSemaphoreTake( xPort->xTestSem, xBlockTime );
	}
	/-----------------------------------------------------------/

	void vSerialClose( xComPortHandle xPort )
	{
	unsigned short usOutput;

	/* Turn off the interrupts. We may also want to delete the queues and/or
	re-install the original ISR. */

	portENTER_CRITICAL();
	{
	usOutput = portINPUT_WORD( xPort->usCtrlReg );

	usOutput &= ~serENABLE_INTERRUPTS;
	usOutput &= ~serENABLE_TX_MACHINES;
	usOutput &= ~serENABLE_RX_MACHINES;
	portOUTPUT_WORD( xPort->usCtrlReg, usOutput );

	usOutput = portINPUT_WORD( xPort->usIntReg );
	usOutput \|= serINTERRUPT_MASK;
	portOUTPUT_WORD( xPort->usIntReg, usOutput );
	}
	portEXIT_CRITICAL();
	}
	/-----------------------------------------------------------/
	unsigned short usStatus;
	static portBASE_TYPE xComPortISR( xComPort * const pxPort )
	{
	unsigned short usStatusRegister;
	char cChar;
	portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;

	/* NOTE: THIS IS NOT AN EFFICIENT ISR AS IT IS DESIGNED SOLELY TO TEST
	THE SCHEDULER FUNCTIONALITY. REAL APPLICATIONS SHOULD NOT USE THIS
	FUNCTION. */

	usStatusRegister = portINPUT_WORD( pxPort->usStatusReg );

	if( usStatusRegister & serRX_READY )
	{
	cChar = ( char ) portINPUT_WORD( pxPort->usRxReg );
	xQueueSendFromISR( pxPort->xRxedChars, &cChar, &xHigherPriorityTaskWoken );

	/* Also release the semaphore - this does nothing interesting and is just a test. */
	xSemaphoreGiveFromISR( pxPort->xTestSem, &xHigherPriorityTaskWoken );
	}
	else if( pxPort->sTxInterruptOn && ( usStatusRegister & serTX_EMPTY ) )
	{
	if( xQueueReceiveFromISR( pxPort->xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )
	{
	portOUTPUT_WORD( pxPort->usTxReg, ( unsigned short ) cChar );
	}
	else
	{
	/* Queue empty, nothing to send */
	vInterruptOff( pxPort, serTX_HOLD_EMPTY_INT );
	}
	}

	serRESET_PIC( pxPort->usIRQVector );

	/* If posting to the queue woke a task that was blocked on the queue we may
	want to switch to the woken task - depending on its priority relative to
	the task interrupted by this ISR. */
	return xHigherPriorityTaskWoken;
	}