/*!
* \file
* <!--
- * Copyright 2003,2004 Develer S.r.l. (http://www.develer.com/)
- * Copyright 2000 Bernardo Innocenti
- * All Rights Reserved.
+ * Copyright 2003, 2004, 2005 Develer S.r.l. (http://www.develer.com/)
+ * Copyright 2000 Bernardo Innocenti <bernie@develer.com>
+ * This file is part of DevLib - See README.devlib for information.
* -->
*
* \version $Id$
*
* \author Bernardo Innocenti <bernie@develer.com>
+ * \author Francesco Sacchi <batt@develer.com>
*
- * \brief Low-level timer module for AVR
- */
-
-/*
- * $Log$
- * Revision 1.1 2004/05/23 18:23:30 bernie
- * Import drv/timer module.
- *
+ * \brief Low-level timer module for AVR (interface).
*/
+/*#*
+ *#* $Log$
+ *#* Revision 1.27 2006/05/18 00:38:24 bernie
+ *#* Use hw_cpu.h instead of ubiquitous hw.h.
+ *#*
+ *#* Revision 1.26 2006/02/21 21:28:02 bernie
+ *#* New time handling based on TIMER_TICKS_PER_SEC to support slow timers with ticks longer than 1ms.
+ *#*
+ *#* Revision 1.25 2005/07/19 07:26:37 bernie
+ *#* Refactor to decouple timer ticks from milliseconds.
+ *#*
+ *#* Revision 1.24 2005/04/11 19:10:28 bernie
+ *#* Include top-level headers from cfg/ subdir.
+ *#*
+ *#* Revision 1.23 2005/03/01 23:24:51 bernie
+ *#* Tweaks for avr-libc 1.2.x.
+ *#*
+ *#* Revision 1.21 2004/12/13 12:07:06 bernie
+ *#* DISABLE_IRQSAVE/ENABLE_IRQRESTORE: Convert to IRQ_SAVE_DISABLE/IRQ_RESTORE.
+ *#*
+ *#* Revision 1.20 2004/11/16 20:59:46 bernie
+ *#* Include <avr/io.h> explicitly.
+ *#*
+ *#* Revision 1.19 2004/10/19 08:56:41 bernie
+ *#* TIMER_STROBE_ON, TIMER_STROBE_OFF, TIMER_STROBE_INIT: Move from timer_avr.h to timer.h, where they really belong.
+ *#*
+ *#* Revision 1.18 2004/09/20 03:31:03 bernie
+ *#* Fix racy racy code.
+ *#*/
#ifndef DRV_TIMER_AVR_H
#define DRV_TIMER_AVR_H
-#include <avr/wdt.h>
-
-# define TIMER_RETRIGGER /* Not needed, timer retriggers automatically */
-
- /*!
- * 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)
+#include <appconfig.h> /* CONFIG_TIMER */
+#include <cfg/compiler.h> /* uint8_t */
+#include <hw_cpu.h> /* CLOCK_FREQ */
-#else
-# error Choose witch timer to use with CONFIG_TIMER_ON_TIMERx
-#endif /* CONFIG_TIMER_ON_TIMERx */
+/*!
+ * \name Values for CONFIG_TIMER.
+ *
+ * Select which hardware timer interrupt to use for system clock and softtimers.
+ * \note The timer 1 overflow mode set the timer as a 24 kHz PWM.
+ *
+ * \{
+ */
+#define TIMER_ON_OUTPUT_COMPARE0 1
+#define TIMER_ON_OVERFLOW1 2
+#define TIMER_ON_OUTPUT_COMPARE2 3
+#define TIMER_ON_OVERFLOW3 4
+/* \} */
+/*
+ * Hardware dependent timer initialization.
+ */
+#if (CONFIG_TIMER == TIMER_ON_OUTPUT_COMPARE0)
-#if defined(CONFIG_TIMER_ON_TIMER1_OVERFLOW)
+ #define TIMER_PRESCALER 64
+ #define TIMER_HW_BITS 8
+ #define DEFINE_TIMER_ISR SIGNAL(SIG_OUTPUT_COMPARE0)
+ #define TIMER_TICKS_PER_SEC 1000
+ #define TIMER_HW_CNT OCR_DIVISOR
- #define DEFINE_TIMER_ISR \
- static void timer_handler(void)
+ //! Type of time expressed in ticks of the hardware high-precision timer
+ typedef uint8_t hptime_t;
- /*
- * Timer 1 overflow irq handler.
- */
- SIGNAL(SIG_OVERFLOW1)
- {
- /*!
- * How many overflow we have to count before calling the true timer handler.
- * If timer overflow is at 24 kHz, with a value of 24 we have 1 ms between
- * each call.
- */
- #define TIMER1_OVF_COUNT 24
+#elif (CONFIG_TIMER == TIMER_ON_OVERFLOW1)
- static uint8_t count = TIMER1_OVF_COUNT;
+ #define TIMER_PRESCALER 1
+ #define TIMER_HW_BITS 8
+ /*! This value is the maximum in overflow based timers. */
+ #define TIMER_HW_CNT (1 << TIMER_HW_BITS)
+ #define DEFINE_TIMER_ISR SIGNAL(SIG_OVERFLOW1)
+ #define TIMER_TICKS_PER_SEC ((TIMER_HW_HPTICKS_PER_SEC + TIMER_HW_CNT / 2) / TIMER_HW_CNT)
- count--;
- if (!count)
- {
- timer_handler();
- count = TIMER1_OVF_COUNT;
- }
- }
+ //! Type of time expressed in ticks of the hardware high precision timer
+ typedef uint16_t hptime_t;
-#elif defined (CONFIG_TIMER_ON_TIMER0)
+#elif (CONFIG_TIMER == TIMER_ON_OUTPUT_COMPARE2)
- #define DEFINE_TIMER_ISR \
- SIGNAL(SIG_OUTPUT_COMPARE0)
+ #define TIMER_PRESCALER 64
+ #define TIMER_HW_BITS 8
+ #define DEFINE_TIMER_ISR SIGNAL(SIG_OUTPUT_COMPARE2)
+ #define TIMER_TICKS_PER_SEC 1000
+ /*! Value for OCR register in output-compare based timers. */
+ #define TIMER_HW_CNT OCR_DIVISOR
-#elif defined(CONFIG_TIMER_ON_TIMER2)
- #define DEFINE_TIMER_ISR \
- SIGNAL(SIG_OUTPUT_COMPARE2)
+ //! Type of time expressed in ticks of the hardware high precision timer
+ typedef uint8_t hptime_t;
+#elif (CONFIG_TIMER == TIMER_ON_OVERFLOW3)
+
+ #define TIMER_PRESCALER 1
+ #define TIMER_HW_BITS 8
+ /*! This value is the maximum in overflow based timers. */
+ #define TIMER_HW_CNT (1 << TIMER_HW_BITS)
+ #define DEFINE_TIMER_ISR SIGNAL(SIG_OVERFLOW3)
+ #define TIMER_TICKS_PER_SEC ((TIMER_HW_HPTICKS_PER_SEC + TIMER_HW_CNT / 2) / TIMER_HW_CNT)
+
+ //! Type of time expressed in ticks of the hardware high precision timer
+ typedef uint16_t hptime_t;
#else
-# error Choose witch timer to use with CONFIG_TIMER_ON_TIMERx
-#endif /* CONFIG_TIMER_ON_TIMERx */
+
+ #error Unimplemented value for CONFIG_TIMER
+#endif /* CONFIG_TIMER */
+
+
+/*! Frequency of the hardware high precision timer. */
+#define TIMER_HW_HPTICKS_PER_SEC ((CLOCK_FREQ + TIMER_PRESCALER / 2) / TIMER_PRESCALER)
+
+/*!
+ * System timer: additional division after the prescaler
+ * 12288000 / 64 / 192 (0..191) = 1 ms
+ */
+#define OCR_DIVISOR (((CLOCK_FREQ + TIMER_PRESCALER / 2) / TIMER_PRESCALER + TIMER_TICKS_PER_SEC / 2) / TIMER_TICKS_PER_SEC - 1)
+
+/*! Not needed, IRQ timer flag cleared automatically */
+#define timer_hw_irq() do {} while (0)
+
#endif /* DRV_TIMER_AVR_H */
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