/* FreeRTOS V9.0.1 - Copyright (C) 2017 Real Time Engineers Ltd. All rights reserved VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION. 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 on the following link: http://www.freertos.org/a00114.html *************************************************************************** * * * FreeRTOS provides completely free yet professionally developed, * * robust, strictly quality controlled, supported, and cross * * platform software that is more than just the market leader, it * * is the industry's de facto standard. * * * * Help yourself get started quickly while simultaneously helping * * to support the FreeRTOS project by purchasing a FreeRTOS * * tutorial book, reference manual, or both: * * http://www.FreeRTOS.org/Documentation * * * *************************************************************************** http://www.FreeRTOS.org/FAQHelp.html - Having a problem? Start by reading the FAQ page "My application does not run, what could be wrong?". Have you defined configASSERT()? http://www.FreeRTOS.org/support - In return for receiving this top quality embedded software for free we request you assist our global community by participating in the support forum. http://www.FreeRTOS.org/training - Investing in training allows your team to be as productive as possible as early as possible. Now you can receive FreeRTOS training directly from Richard Barry, CEO of Real Time Engineers Ltd, and the world's leading authority on the world's leading RTOS. 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.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate. Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS. http://www.OpenRTOS.com - Real Time Engineers ltd. license FreeRTOS to High Integrity Systems ltd. to sell under the OpenRTOS brand. Low cost OpenRTOS licenses offer ticketed support, indemnification and commercial 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 = ( uint8_t ) ( ( portTIMER_COMPARE_VALUE >> 8 ) & 0xff ); CCPR1L = ( uint8_t ) ( 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 = ( uint8_t ) 0x00; TMR1L = ( uint8_t ) 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 }