- /*!
- * System timer: additional division after the prescaler
- * 12288000 / 64 / 192 (0..191) = 1 ms
- */
-# define OCR_DIVISOR 191
-
- /*! HW dependent timer initialization */
-#if defined(CONFIG_TIMER_ON_TIMER0)
-
-# define TIMER_INIT \
- do { \
- DISABLE_INTS; \
- \
- /* Reset Timer flags */ \
- TIFR = BV(OCF0) | BV(TOV0); \
- \
- /* Setup Timer/Counter interrupt */ \
- ASSR = 0x00; /* internal system clock */ \
- TCCR0 = BV(WGM01) | BV(CS02); /* Clear on Compare match & prescaler = 64 */ \
- TCNT0 = 0x00; /* initialization of Timer/Counter */ \
- OCR0 = OCR_DIVISOR; /* Timer/Counter Output Compare Register */ \
- \
- /* Enable timer interrupts: Timer/Counter2 Output Compare (OCIE2) */ \
- TIMSK &= ~BV(TOIE0); \
- TIMSK |= BV(OCIE0); \
- \
- ENABLE_INTS; \
- } while (0)
-
-#elif defined(CONFIG_TIMER_ON_TIMER1_OVERFLOW)
-
-# define TIMER_INIT \
- do { \
- DISABLE_INTS; \
- \
- /* Reset Timer overflow flag */ \
- TIFR |= BV(TOV1); \
- \
- /* Fast PWM mode, 24 kHz, no prescaling */ \
- TCCR1A |= BV(WGM11); \
- TCCR1A &= ~BV(WGM10); \
- TCCR1B |= BV(WGM12) | BV(CS10); \
- TCCR1B &= ~(BV(WGM13) | BV(CS11) | BV(CS12)); \
- \
- TCNT1 = 0x00; /* initialization of Timer/Counter */ \
- \
- /* Enable timer interrupt: Timer/Counter1 Overflow */ \
- TIMSK |= BV(TOIE1); \
- \
- ENABLE_INTS; \
- } while (0)
-
-#elif defined(CONFIG_TIMER_ON_TIMER2)
-
-# 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)
+/*!
+ * System timer: additional division after the prescaler
+ * 12288000 / 64 / 192 (0..191) = 1 ms
+ */
+#define OCR_DIVISOR (CLOCK_FREQ / TIMER_PRESCALER / TICKS_PER_SEC - 1) /* 191 */
+
+/*! HW dependent timer initialization */
+#if (CONFIG_TIMER == TIMER_ON_OUTPUT_COMPARE0)
+
+ //! 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(OCF0) | BV(TOV0);
+
+ /* Setup Timer/Counter interrupt */
+ ASSR = 0x00; /* Internal system clock */
+ TCCR0 = BV(WGM01) /* Clear on Compare match */
+ #if TIMER_PRESCALER == 64
+ | BV(CS02)
+ #else
+ #error Unsupported value of TIMER_PRESCALER
+ #endif
+ ;
+ TCNT0 = 0x00; /* Initialization of Timer/Counter */
+ OCR0 = OCR_DIVISOR; /* Timer/Counter Output Compare Register */
+
+ /* Enable timer interrupts: Timer/Counter2 Output Compare (OCIE2) */
+ TIMSK &= ~BV(TOIE0);
+ TIMSK |= BV(OCIE0);
+
+ ENABLE_IRQRESTORE(flags);
+ }
+
+ //! Frequency of the hardware high precision timer
+ #define TIMER_HW_HPTICKS_PER_SEC (CLOCK_FREQ / TIMER_PRESCALER)
+
+ INLINE hptime_t timer_hw_hpread(void)
+ {
+ return TCNT0;
+ }
+
+#elif (CONFIG_TIMER == TIMER_ON_OVERFLOW1)
+
+ //! Type of time expressed in ticks of the hardware high precision timer
+ typedef uint16_t hptime_t;
+
+ static void timer_hw_init(void)
+ {
+ cpuflags_t flags;
+ DISABLE_IRQSAVE(flags);
+
+ /* Reset Timer overflow flag */
+ TIFR |= BV(TOV1);
+
+ /* Fast PWM mode, 9 bit, 24 kHz, no prescaling. When changing freq or
+ resolution (top of TCNT), change TIMER_HW_HPTICKS_PER_SEC too */
+ TCCR1A |= BV(WGM11);
+ TCCR1A &= ~BV(WGM10);
+ TCCR1B |= BV(WGM12) | BV(CS10);
+ TCCR1B &= ~(BV(WGM13) | BV(CS11) | BV(CS12));
+
+ TCNT1 = 0x00; /* initialization of Timer/Counter */
+
+ /* Enable timer interrupt: Timer/Counter1 Overflow */
+ TIMSK |= BV(TOIE1);
+
+ ENABLE_IRQRESTORE(flags);
+ }
+
+ //! Frequency of the hardware high precision timer
+ #define TIMER_HW_HPTICKS_PER_SEC (24000ul * 512)
+
+ INLINE hptime_t timer_hw_hpread(void)
+ {
+ return TCNT1;
+ }
+
+#elif (CONFIG_TIMER == TIMER_ON_OUTPUT_COMPARE2)
+
+ //! 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)
+ #if TIMER_PRESCALER == 64
+ | BV(CS21) | BV(CS20)
+ #else
+ #error Unsupported value of TIMER_PRESCALER
+ #endif
+ ;
+ /* 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 / TIMER_PRESCALER)
+
+ INLINE hptime_t timer_hw_hpread(void)
+ {
+ return TCNT2;
+ }