/* FreeRTOS V8.0.0:rc1 - Copyright (C) 2014 Real Time Engineers Ltd. All rights reserved VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION. *************************************************************************** * * * FreeRTOS provides completely free yet professionally developed, * * robust, strictly quality controlled, supported, and cross * * platform software that has become a de facto standard. * * * * Help yourself get started quickly and support the FreeRTOS * * project by purchasing a FreeRTOS tutorial book, reference * * manual, or both from: http://www.FreeRTOS.org/Documentation * * * * Thank you! * * * *************************************************************************** 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. Full license text is available from the following link: http://www.freertos.org/a00114.html 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, a DOS compatible FAT file system, and our tiny thread aware UDP/IP stack. http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS licenses offer ticketed support, indemnification and middleware. 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. 1 tab == 4 spaces! */ /* BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR DEMO PURPOSES */ #include #include "FreeRTOS.h" #include "queue.h" #include "task.h" #include "serial.h" /* Constants required to setup the serial control register. */ #define ser8_BIT_MODE ( ( unsigned char ) 0x40 ) #define serRX_ENABLE ( ( unsigned char ) 0x10 ) /* Constants to setup the timer used to generate the baud rate. */ #define serCLOCK_DIV_48 ( ( unsigned char ) 0x03 ) #define serUSE_PRESCALED_CLOCK ( ( unsigned char ) 0x10 ) #define ser8BIT_WITH_RELOAD ( ( unsigned char ) 0x20 ) #define serSMOD ( ( unsigned char ) 0x10 ) static xQueueHandle xRxedChars; static xQueueHandle xCharsForTx; data static unsigned portBASE_TYPE uxTxEmpty; /*-----------------------------------------------------------*/ xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength ) { unsigned long ulReloadValue; const portFLOAT fBaudConst = ( portFLOAT ) configCPU_CLOCK_HZ * ( portFLOAT ) 2.0; unsigned char ucOriginalSFRPage; portENTER_CRITICAL(); { ucOriginalSFRPage = SFRPAGE; SFRPAGE = 0; uxTxEmpty = pdTRUE; /* Create the queues used by the com test task. */ xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( char ) ); xCharsForTx = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( char ) ); /* Calculate the baud rate to use timer 1. */ ulReloadValue = ( unsigned long ) ( ( ( portFLOAT ) 256 - ( fBaudConst / ( portFLOAT ) ( 32 * ulWantedBaud ) ) ) + ( portFLOAT ) 0.5 ); /* Set timer one for desired mode of operation. */ TMOD &= 0x08; TMOD |= ser8BIT_WITH_RELOAD; SSTA0 |= serSMOD; /* Set the reload and start values for the time. */ TL1 = ( unsigned char ) ulReloadValue; TH1 = ( unsigned char ) ulReloadValue; /* Setup the control register for standard n, 8, 1 - variable baud rate. */ SCON = ser8_BIT_MODE | serRX_ENABLE; /* Enable the serial port interrupts */ ES = 1; /* Start the timer. */ TR1 = 1; SFRPAGE = ucOriginalSFRPage; } portEXIT_CRITICAL(); /* Unlike some ports, this serial code does not allow for more than one com port. We therefore don't return a pointer to a port structure and can instead just return NULL. */ return NULL; } /*-----------------------------------------------------------*/ void vSerialISR( void ) interrupt 4 { char cChar; portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE; /* 8051 port interrupt routines MUST be placed within a critical section if taskYIELD() is used within the ISR! */ portENTER_CRITICAL(); { if( RI ) { /* Get the character and post it on the queue of Rxed characters. If the post causes a task to wake force a context switch if the woken task has a higher priority than the task we have interrupted. */ cChar = SBUF; RI = 0; xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken ); } if( TI ) { if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == ( portBASE_TYPE ) pdTRUE ) { /* Send the next character queued for Tx. */ SBUF = cChar; } else { /* Queue empty, nothing to send. */ uxTxEmpty = pdTRUE; } TI = 0; } if( xHigherPriorityTaskWoken ) { portYIELD(); } } portEXIT_CRITICAL(); } /*-----------------------------------------------------------*/ portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, portTickType xBlockTime ) { /* There is only one port supported. */ ( void ) pxPort; /* Get the next character from the buffer. Return false if no characters are available, or arrive before xBlockTime expires. */ if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) ) { return ( portBASE_TYPE ) pdTRUE; } else { return ( portBASE_TYPE ) pdFALSE; } } /*-----------------------------------------------------------*/ portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, portTickType xBlockTime ) { portBASE_TYPE xReturn; /* There is only one port supported. */ ( void ) pxPort; portENTER_CRITICAL(); { if( uxTxEmpty == pdTRUE ) { SBUF = cOutChar; uxTxEmpty = pdFALSE; xReturn = ( portBASE_TYPE ) pdTRUE; } else { xReturn = xQueueSend( xCharsForTx, &cOutChar, xBlockTime ); if( xReturn == ( portBASE_TYPE ) pdFALSE ) { xReturn = ( portBASE_TYPE ) pdTRUE; } } } portEXIT_CRITICAL(); return xReturn; } /*-----------------------------------------------------------*/ void vSerialClose( xComPortHandle xPort ) { /* Not implemented in this port. */ ( void ) xPort; } /*-----------------------------------------------------------*/