[moodlight.git] / timers.h

/* $Id: timers.h,v 1.1 2010/06/27 22:18:26 simimeie Exp $
 * Functions for timing.
 * This mainly allows you to get a timestamp value
 */

#ifndef _TIMERS_H_
#define _TIMERS_H_

/* timestamps are usually delivered in 'ticks'.
 * At 8.0 MHz, there are ca. 122 ticks per second, and the 16 bit tick counter
 * overflows about every 536 seconds.
 * If you need exacter timing, you can also get a struct timestamp.
 * That will contain the tick value and the current counter value as
 * an uint16, giving you a precision of up to 1 cpu cycle. */

#define TICKSPERSECOND (CPUFREQ / 65536UL)
#define TICKSPERSECONDF ((float)CPUFREQ / 65536.0)

struct timestamp {
  uint16_t ticks;
  uint16_t partticks;
};

/* Init timers */
void timers_init(void);

/* get ticks.
 * Warning: Will reenable interrupts if they were disabled. */
uint16_t getticks(void);
/* The same, but won't touch the global interrupt enable bit.
 * MUST BE CALLED WITH INTERRUPTS DISABLED */
uint16_t getticks_noirq(void);

/* get timestamp
 * Warning: Will reenable interrupts if they were disabled. */
struct timestamp gettimestamp(void);
/* The same, but won't touch the global interrupt enable bit.
 * MUST BE CALLED WITH INTERRUPTS DISABLED */
struct timestamp gettimestamp_noirq(void);

#endif /* _TIMERS_H_ */
Commit	Line	Data
10ee5c5d	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_ */