2 Copyright 2011 Jun Wako <wakojun@gmail.com>
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation, either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>.
19 #include <avr/interrupt.h>
20 #include <util/atomic.h>
22 #include "timer_avr.h"
26 // counter resolution 1ms
27 // NOTE: union { uint32_t timer32; struct { uint16_t dummy; uint16_t timer16; }}
28 volatile uint32_t timer_count;
30 /** \brief timer initialization
36 #if TIMER_PRESCALER == 1
37 uint8_t prescaler = 0x01;
38 #elif TIMER_PRESCALER == 8
39 uint8_t prescaler = 0x02;
40 #elif TIMER_PRESCALER == 64
41 uint8_t prescaler = 0x03;
42 #elif TIMER_PRESCALER == 256
43 uint8_t prescaler = 0x04;
44 #elif TIMER_PRESCALER == 1024
45 uint8_t prescaler = 0x05;
47 # error "Timer prescaler value is NOT vaild."
50 #ifndef __AVR_ATmega32A__
56 OCR0A = TIMER_RAW_TOP;
60 TCCR0 = (1 << WGM01) | prescaler;
67 /** \brief timer clear
72 void timer_clear(void)
74 ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
84 uint16_t timer_read(void)
88 ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
95 /** \brief timer read32
100 uint32_t timer_read32(void)
104 ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
111 /** \brief timer elapsed
116 uint16_t timer_elapsed(uint16_t last)
120 ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
124 return TIMER_DIFF_16((t & 0xFFFF), last);
127 /** \brief timer elapsed32
132 uint32_t timer_elapsed32(uint32_t last)
136 ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
140 return TIMER_DIFF_32(t, last);
143 // excecuted once per 1ms.(excess for just timer count?)
144 #ifndef __AVR_ATmega32A__
145 #define TIMER_INTERRUPT_VECTOR TIMER0_COMPA_vect
147 #define TIMER_INTERRUPT_VECTOR TIMER0_COMP_vect
149 ISR(TIMER_INTERRUPT_VECTOR, ISR_NOBLOCK)