-# define TIMER_INIT \
- do { \
- DISABLE_INTS; \
- \
- /* Reset Timer flags */ \
- TIFR = BV(OCF2) | BV(TOV2); \
- \
- /* Setup Timer/Counter interrupt */ \
- TCCR2 = BV(WGM21) | BV(CS21) | BV(CS20); \
- /* Clear on Compare match & prescaler = 64, internal sys clock */ \
- TCNT2 = 0x00; /* initialization of Timer/Counter */ \
- OCR2 = OCR_DIVISOR; /* Timer/Counter Output Compare Register */ \
- \
- /* Enable timer interrupts: Timer/Counter2 Output Compare (OCIE2) */ \
- TIMSK &= ~BV(TOIE2); \
- TIMSK |= BV(OCIE2); \
- \
- ENABLE_INTS; \
- } while (0)
+ //! Type of time expressed in ticks of the hardware high precision timer
+ typedef uint8_t hptime_t;
+
+ static void timer_hw_init(void)
+ {
+ cpuflags_t flags;
+ DISABLE_IRQSAVE(flags);
+
+ /* Reset Timer flags */
+ TIFR = BV(OCF2) | BV(TOV2);
+
+ /* Setup Timer/Counter interrupt */
+ TCCR2 = BV(WGM21) | BV(CS21) | BV(CS20);
+ /* Clear on Compare match & prescaler = 64, internal sys clock.
+ When changing prescaler change TIMER_HW_HPTICKS_PER_SEC too */
+ TCNT2 = 0x00; /* initialization of Timer/Counter */
+ OCR2 = OCR_DIVISOR; /* Timer/Counter Output Compare Register */
+
+ /* Enable timer interrupts: Timer/Counter2 Output Compare (OCIE2) */
+ TIMSK &= ~BV(TOIE2);
+ TIMSK |= BV(OCIE2);
+
+ ENABLE_IRQRESTORE(flags);
+ }
+
+ //! Frequency of the hardware high precision timer
+ #define TIMER_HW_HPTICKS_PER_SEC (CLOCK_FREQ / 64)
+
+ INLINE hptime_t timer_hw_hpread(void);
+ INLINE hptime_t timer_hw_hpread(void)
+ {
+ return TCNT2;
+ }