/* FreeRTOS V7.6.0 - Copyright (C) 2013 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! */ /* 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 }