/* FreeRTOS V7.4.2 - 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 it can 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. */ /* Changes from V3.0.0 + ISRcode is pulled inline and portTICKisr() is therefore deleted from this file. + Prescaler logic for Timer1 added to allow for a wider range of TickRates. Changes from V3.0.1 */ #include #include /* IO port constants. */ #define portBIT_SET (1) #define portBIT_CLEAR (0) /* * Hardware setup for the tick. * We use a compare match on timer1. Depending on MPU-frequency * and requested tickrate, a prescaled value with a matching * prescaler are determined. */ #define portTIMER_COMPARE_BASE ((APROCFREQ/4)/configTICK_RATE_HZ) #if portTIMER_COMPARE_BASE < 0x10000 #define portTIMER_COMPARE_VALUE (portTIMER_COMPARE_BASE) #define portTIMER_COMPARE_PS1 (portBIT_CLEAR) #define portTIMER_COMPARE_PS0 (portBIT_CLEAR) #elif portTIMER_COMPARE_BASE < 0x20000 #define portTIMER_COMPARE_VALUE (portTIMER_COMPARE_BASE / 2) #define portTIMER_COMPARE_PS1 (portBIT_CLEAR) #define portTIMER_COMPARE_PS0 (portBIT_SET) #elif portTIMER_COMPARE_BASE < 0x40000 #define portTIMER_COMPARE_VALUE (portTIMER_COMPARE_BASE / 4) #define portTIMER_COMPARE_PS1 (portBIT_SET) #define portTIMER_COMPARE_PS0 (portBIT_CLEAR) #elif portTIMER_COMPARE_BASE < 0x80000 #define portTIMER_COMPARE_VALUE (portTIMER_COMPARE_BASE / 8) #define portTIMER_COMPARE_PS1 (portBIT_SET) #define portTIMER_COMPARE_PS0 (portBIT_SET) #else #error "TickRate out of range" #endif /*-----------------------------------------------------------*/ /* * Setup a timer for a regular tick. */ void portSetupTick( void ) { /* * Interrupts are disabled when this function is called. */ /* * Setup CCP1 * Provide the tick interrupt using a compare match on timer1. */ /* * Set the compare match value. */ CCPR1H = ( unsigned char ) ( ( portTIMER_COMPARE_VALUE >> 8 ) & 0xff ); CCPR1L = ( unsigned char ) ( portTIMER_COMPARE_VALUE & 0xff ); /* * Set Compare Special Event Trigger Mode */ bCCP1M3 = portBIT_SET; bCCP1M2 = portBIT_CLEAR; bCCP1M1 = portBIT_SET; bCCP1M0 = portBIT_SET; /* * Enable CCP1 interrupt */ bCCP1IE = portBIT_SET; /* * We are only going to use the global interrupt bit, so disable * interruptpriorities and enable peripheral interrupts. */ bIPEN = portBIT_CLEAR; bPEIE = portBIT_SET; /* * Set up timer1 * It will produce the system tick. */ /* * Clear the time count */ TMR1H = ( unsigned char ) 0x00; TMR1L = ( unsigned char ) 0x00; /* * Setup the timer */ bRD16 = portBIT_SET; // 16-bit bT1CKPS1 = portTIMER_COMPARE_PS1; // prescaler bT1CKPS0 = portTIMER_COMPARE_PS0; // prescaler bT1OSCEN = portBIT_SET; // Oscillator enable bT1SYNC = portBIT_SET; // No external clock sync bTMR1CS = portBIT_CLEAR; // Internal clock bTMR1ON = portBIT_SET; // Start timer1 }