blob: 88fa1dfa65feefb6457137d6d52805f07243d177 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
|
/*
Copyright 2011 Jun Wako <wakojun@gmail.com>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.
This program 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
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <avr/io.h>
#include <avr/interrupt.h>
#include <util/atomic.h>
#include <stdint.h>
#include "timer_avr.h"
#include "timer.h"
// counter resolution 1ms
// NOTE: union { uint32_t timer32; struct { uint16_t dummy; uint16_t timer16; }}
volatile uint32_t timer_count;
/** \brief timer initialization
*
* FIXME: needs doc
*/
void timer_init(void) {
#if TIMER_PRESCALER == 1
uint8_t prescaler = _BV(CS00);
#elif TIMER_PRESCALER == 8
uint8_t prescaler = _BV(CS01);
#elif TIMER_PRESCALER == 64
uint8_t prescaler = _BV(CS00) | _BV(CS01);
#elif TIMER_PRESCALER == 256
uint8_t prescaler = _BV(CS02);
#elif TIMER_PRESCALER == 1024
uint8_t prescaler = _BV(CS00) | _BV(CS02);
#else
# error "Timer prescaler value is not valid"
#endif
#ifndef __AVR_ATmega32A__
// Timer0 CTC mode
TCCR0A = _BV(WGM01);
TCCR0B = prescaler;
OCR0A = TIMER_RAW_TOP;
TIMSK0 = _BV(OCIE0A);
#else
// Timer0 CTC mode
TCCR0 = _BV(WGM01) | prescaler;
OCR0 = TIMER_RAW_TOP;
TIMSK = _BV(OCIE0);
#endif
}
/** \brief timer clear
*
* FIXME: needs doc
*/
inline void timer_clear(void) {
ATOMIC_BLOCK(ATOMIC_RESTORESTATE) { timer_count = 0; }
}
/** \brief timer read
*
* FIXME: needs doc
*/
inline uint16_t timer_read(void) {
uint32_t t;
ATOMIC_BLOCK(ATOMIC_RESTORESTATE) { t = timer_count; }
return (t & 0xFFFF);
}
/** \brief timer read32
*
* FIXME: needs doc
*/
inline uint32_t timer_read32(void) {
uint32_t t;
ATOMIC_BLOCK(ATOMIC_RESTORESTATE) { t = timer_count; }
return t;
}
/** \brief timer elapsed
*
* FIXME: needs doc
*/
inline uint16_t timer_elapsed(uint16_t last) {
uint32_t t;
ATOMIC_BLOCK(ATOMIC_RESTORESTATE) { t = timer_count; }
return TIMER_DIFF_16((t & 0xFFFF), last);
}
/** \brief timer elapsed32
*
* FIXME: needs doc
*/
inline uint32_t timer_elapsed32(uint32_t last) {
uint32_t t;
ATOMIC_BLOCK(ATOMIC_RESTORESTATE) { t = timer_count; }
return TIMER_DIFF_32(t, last);
}
// excecuted once per 1ms.(excess for just timer count?)
#ifndef __AVR_ATmega32A__
# define TIMER_INTERRUPT_VECTOR TIMER0_COMPA_vect
#else
# define TIMER_INTERRUPT_VECTOR TIMER0_COMP_vect
#endif
ISR(TIMER_INTERRUPT_VECTOR, ISR_NOBLOCK) { timer_count++; }
|
