blob: c83cc4226adb539e52536d5d2a8354c9c296f4c0 (
plain)
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
|
#define HAVE_TICK
static union {
uint32_t u32;
uint8_t u8[4];
} systick = { .u32 = 0 };
#ifndef SYSTICK_USER_1HZ
#define systick_user_1hz()
#endif
static uint8_t tick_sub;
ISR(TIMER1_COMPA_vect)
{
#ifdef SYSTICK_USER_100HZ
systick_user_100hz();
if (++tick_sub < 100)
return;
tick_sub = 0;
#endif
systick.u32++;
systick_user_1hz();
}
static void uart_puttick(void)
{
uint16_t frac = TCNT1;
_uart_putch('@');
uart_puthex(systick.u8[3]);
uart_puthex(systick.u8[2]);
uart_puthex(systick.u8[1]);
uart_puthex(systick.u8[0]);
_uart_putch('.');
#ifdef SYSTICK_USER_100HZ
uart_puthex(tick_sub);
#else
uart_puthex16(frac);
#endif
#if DEBUG_SP
_uart_putch('~');
uint8_t spl, sph;
asm ("\n\
in %[spl], 0x3d\n\
in %[sph], 0x3e\n\
" : [spl] "=r" (spl), [sph] "=r" (sph));
uart_puthex(sph);
uart_puthex(spl);
#endif
_uart_putch(' ');
}
static void tick_init(void)
{
TCCR1A = 0;
#ifdef SYSTICK_USER_100HZ
TCCR1B = (1 << WGM12) | (0 << CS12) | (1 << CS11) | (0 << CS10); // 8 MHz / 8 = 1 MHz
asm volatile ("" ::: "memory");
TCNT1 = 0;
OCR1A = 9999; // 100 Hz
#else
TCCR1B = (1 << WGM12) | (1 << CS12) | (0 << CS11) | (0 << CS10); // 8 MHz / 256 = 31250 Hz
asm volatile ("" ::: "memory");
TCNT1 = 0;
OCR1A = 31249; // 1 Hz
#endif
asm volatile ("" ::: "memory");
TIFR1 = (1 << OCF1A);
TIMSK1 = (1 << OCIE1A);
}
|
