00001 /* 00002 00003 Copyright (c) 2010, Embedded Adventures, www.embeddedadventures.com 00004 All rights reserved. 00005 00006 Redistribution and use in source and binary forms, with or without 00007 modification, are permitted provided that the following conditions are met: 00008 00009 - Redistributions of source code must retain the above copyright notice, 00010 this list of conditions and the following disclaimer. 00011 00012 - Redistributions in binary form must reproduce the above copyright 00013 notice, this list of conditions and the following disclaimer in the 00014 documentation and/or other materials provided with the distribution. 00015 00016 - Neither the name of Embedded Adventures nor the names of its contributors 00017 may be used to endorse or promote products derived from this software 00018 without specific prior written permission. 00019 00020 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 00021 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 00022 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 00023 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 00024 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 00025 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 00026 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 00027 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 00028 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 00029 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 00030 THE POSSIBILITY OF SUCH DAMAGE. 00031 00032 Contact us at admin@embeddedadventures.com 00033 00034 */ 00035 00041 #include "pic_tick.h" 00042 00043 void timer_0_callback() { 00044 handle_tick_inline(); 00045 } 00046 00047 uns16 tick_get_count() { 00048 00049 uns16 result; 00050 00051 start_crit_sec(); 00052 result = tick; // Grab a copy 00053 00054 end_crit_sec(); // interrupts back to normal 00055 return result; // return the result 00056 } 00057 00058 uns16 tick_calc_diff(uns16 a, uns16 b) { 00059 if (a <= b) { // simple case 00060 return b-a; 00061 } else { 00062 return 65535 - a + b + 1; // more complex case 00063 } 00064 } 00065 00066 void handle_tick() { 00067 tick++; // we assume that interrupts are off at this point 00068 } 00069 00070