timer_xmega.h

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#ifndef DRV_TIMER_XMEGA_H
#define DRV_TIMER_XMEGA_H

#include <hw/hw_cpufreq.h>   /* CPU_FREQ */

#include "cfg/cfg_timer.h"   /* CONFIG_TIMER */
#include <cfg/compiler.h>    /* uint8_t */
#include <cfg/macros.h>      /* DIV_ROUND */

#include <avr/io.h>
#include <avr/interrupt.h>

/*
 * \name Values for CONFIG_TIMER.
 *
 * Select which hardware timer interrupt to use for system clock and softtimers.
 * $WIZ$ timer_select = "TIMER_USE_TCC0", "TIMER_USE_TCC1", "TIMER_USE_TCD0", "TIMER_USE_TCE0", "TIMER_USE_TCD1", "TIMER_DEFAULT"
 */
#define TIMER_USE_TCC0    1
#define TIMER_USE_TCC1    2
#define TIMER_USE_TCD0    3
#define TIMER_USE_TCE0    4
// The XMEGA A Family has one extra timer
#ifdef CPU_AVR_XMEGA_A
    #define TIMER_USE_TCD1    5
#endif

#define TIMER_DEFAULT TIMER_USE_TCC1 ///< Default system timer

/*
 * Hardware dependent timer initialization.
 */
#if (CONFIG_TIMER == TIMER_USE_TCC0)
    #define TIMER_OVF_VECT  TCC0_OVF_vect
    #define TIMERCOUNTER    TCC0
#elif (CONFIG_TIMER == TIMER_USE_TCC1)
    #define TIMER_OVF_VECT  TCC1_OVF_vect
    #define TIMERCOUNTER    TCC1
#elif (CONFIG_TIMER == TIMER_USE_TCD0)
    #define TIMER_OVF_VECT  TCD0_OVF_vect
    #define TIMERCOUNTER    TCD0
#elif (CONFIG_TIMER == TIMER_USE_TCE0)
    #define TIMER_OVF_VECT  TCE0_OVF_vect
    #define TIMERCOUNTER    TCE0
#elif (CONFIG_TIMER == TIMER_USE_TCD1)
    #define TIMER_OVF_VECT  TCD1_OVF_vect
    #define TIMERCOUNTER    TCD1
#else
    #error Unimplemented value for CONFIG_TIMER
#endif /* CONFIG_TIMER */

//define the Interrupt Service Routine for this Timer Mode
#define DEFINE_TIMER_ISR            DECLARE_ISR_CONTEXT_SWITCH(TIMER_OVF_VECT)
//define the Ticks per second we want
#define TIMER_TICKS_PER_SEC         1000
//define the Prescaler to use, which is dependend on the amount
//of ticks per second, the maximum value for the TOP value of the
//timer (0xFFFF) and the clock frequency.
//The maximum clock frequency is 32Mhz, so as long as the TIMER_TICKS_PER_SEC
//is larger then (about) 500 no prescaler is required.
#define TIMER_PRESCALER             1
//define the TOP/PERIOD value
#define TIMER_PERIOD_VALUE          DIV_ROUND(DIV_ROUND(CPU_FREQ, TIMER_PRESCALER), TIMER_TICKS_PER_SEC)
//check if the TIMER_PRESCALER is large enough to accomate for the TIMER_TICKS_PER_SEC
#if TIMER_PERIOD_VALUE > 0xFFFF
    #error Timer cannot generate the required Ticks per second, please adjust TIMER_PRESCALER
#endif
//define TIMER_HW_CNT it is used by the timer.c module to determine the 'edge' of the hardware counter
#define TIMER_HW_CNT                TIMER_PERIOD_VALUE

#define TIMER_HW_HPTICKS_PER_SEC    DIV_ROUND(CPU_FREQ, TIMER_PRESCALER)

// Type of time expressed in ticks of the hardware high-precision timer
typedef uint16_t hptime_t;
#define SIZEOF_HPTIME_T 2

INLINE hptime_t timer_hw_hpread(void)
{
    return (TIMERCOUNTER).CNT;
}

/* Not needed, IRQ timer flag cleared automatically */
#define timer_hw_irq() do {} while (0)

/* Not needed, timer IRQ handler called only for timer source */
#define timer_hw_triggered() (true)

void timer_hw_init(void);

#endif /* DRV_TIMER_XMEGA_H */