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1 | /* $Id: timers.h,v 1.1 2010/06/27 22:18:26 simimeie Exp $ |
2 | * Functions for timing. |
3 | * This mainly allows you to get a timestamp value |
4 | */ |
5 | |
6 | #ifndef _TIMERS_H_ |
7 | #define _TIMERS_H_ |
8 | |
9 | /* timestamps are usually delivered in 'ticks'. |
10 | * At 8.0 MHz, there are ca. 122 ticks per second, and the 16 bit tick counter |
11 | * overflows about every 536 seconds. |
12 | * If you need exacter timing, you can also get a struct timestamp. |
13 | * That will contain the tick value and the current counter value as |
14 | * an uint16, giving you a precision of up to 1 cpu cycle. */ |
15 | |
16 | #define TICKSPERSECOND (CPUFREQ / 65536UL) |
17 | #define TICKSPERSECONDF ((float)CPUFREQ / 65536.0) |
18 | |
19 | struct timestamp { |
20 | uint16_t ticks; |
21 | uint16_t partticks; |
22 | }; |
23 | |
24 | /* Init timers */ |
25 | void timers_init(void); |
26 | |
27 | /* get ticks. |
28 | * Warning: Will reenable interrupts if they were disabled. */ |
29 | uint16_t getticks(void); |
30 | /* The same, but won't touch the global interrupt enable bit. |
31 | * MUST BE CALLED WITH INTERRUPTS DISABLED */ |
32 | uint16_t getticks_noirq(void); |
33 | |
34 | /* get timestamp |
35 | * Warning: Will reenable interrupts if they were disabled. */ |
36 | struct timestamp gettimestamp(void); |
37 | /* The same, but won't touch the global interrupt enable bit. |
38 | * MUST BE CALLED WITH INTERRUPTS DISABLED */ |
39 | struct timestamp gettimestamp_noirq(void); |
40 | |
41 | #endif /* _TIMERS_H_ */ |