2021年2月 – ページ 8

【タイマー管理クラス】

このタイマー管理クラスはタイマー０の比較一致割り込みにより動作する。

arduinoなどではタイマー０のOC0A/OC0B出力ピンをＰＷＭとして使用できるが、ＰＷＭとして使うとタイマー０の設定が書き換わり、このタイマー管理クラスが誤動作するので注意してほしい。

代表的なボードのＰＷＭとして使ってはいけないピンは次の通り。

UNO(ATmega328)       ... D5, D6
LEONARDO(ATmega32u4) ... D3, D11

1 2	UNO(ATmega328) ... D5, D6 LEONARDO(ATmega32u4) ... D3, D11

正確なシステム時刻を管理するため比較一致割り込みの一つを使い独自にシステム時刻カウンターを実装し、もう一つの比較一致割り込みはスリープやタイムアウトを管理するためのタイマーとして使用している。また、システム時刻の取得は割り込み処理内などの割り込み禁止状態からの呼び出しでも問題ないよう工夫している。

【概要】

static void begin(void);

1	static void begin(void);

※タイマー初期設定。内部用なので呼び出してはいけない。

static uint32_t micros(void);

1	static uint32_t micros(void);

arduino互換。システム起動後の経過時間をマイクロ秒で返す。

static uint32_t millis(void);

1	static uint32_t millis(void);

arduino互換。システム起動後の経過時間をミリ秒で返す。

static void delay(int32_t ms);

1	static void delay(int32_t ms);

arduino互換。指定ミリ秒の間、スリープする。

static void delayMicroseconds(int32_t us);

1	static void delayMicroseconds(int32_t us);

arduino互換。指定マイクロ秒の間、スリープする。

【ソース・コード】

/*
  timer.h - Timer Function Class

  Copyright (c) 2021 Sasapea's Lab. All right reserved.

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.

  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General
  Public License along with this library; if not, write to the
  Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  Boston, MA  02111-1307  USA
*/
#ifndef __TIMER_H
#define __TIMER_H

#include <stdint.h>
#include <stdbool.h>

#define WAIT_TIMEOUT 0xFF
#define WAIT_OBJECT  0

#define WAIT_INFINITE -1

class Timer : protected Task
{
  private:

    static void timer0_compb_vect(void);
    static uint32_t clock(bool us);
    static void init(int32_t count);
    static void restart(uint32_t time);
    static bool wakeup_match(TASK_T *task, uint32_t time);
    static bool insert_match(TASK_T *task, uint32_t time);

    friend void timer0_compb_vect(void);

  protected:

    static void setup(TASK_T *task, int32_t timeout, Timer *wait);
    static void cansel(TASK_T *task);

    virtual void timeout(TASK_T *task) = 0;

  public:

    static void begin(void);
    static uint32_t micros(void);
    static uint32_t millis(void);
    static void delay(int32_t ms);
    static void delayMicroseconds(int32_t us);
};

#endif

timer.h - Timer Function Class

This library is free software; you can redistribute it and/or

modify it under the terms of the GNU Lesser General Public

License as published by the Free Software Foundation; either

version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General

Public License along with this library; if not, write to the

Free Software Foundation, Inc., 59 Temple Place, Suite 330,

Boston, MA 02111-1307 USA

#ifndef __TIMER_H

#define __TIMER_H

#include <stdint.h>

#include <stdbool.h>

#define WAIT_TIMEOUT 0xFF

#define WAIT_OBJECT 0

#define WAIT_INFINITE -1

class Timer : protected Task

{

private:

static void timer0_compb_vect(void);

static uint32_t clock(bool us);

static void init(int32_t count);

static void restart(uint32_t time);

static bool wakeup_match(TASK_T *task, uint32_t time);

static bool insert_match(TASK_T *task, uint32_t time);

friend void timer0_compb_vect(void);

protected:

static void setup(TASK_T *task, int32_t timeout, Timer *wait);

static void cansel(TASK_T *task);

virtual void timeout(TASK_T *task) = 0;

public:

static void begin(void);

static uint32_t micros(void);

static uint32_t millis(void);

static void delay(int32_t ms);

static void delayMicroseconds(int32_t us);

};

#endif

/*
  timer.cpp - Timer Function Class

  Copyright (c) 2021 Sasapea's Lab. All right reserved.

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.

  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General
  Public License along with this library; if not, write to the
  Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  Boston, MA  02111-1307  USA
*/
#include <stdint.h>
#include <stdbool.h>
#include <avr/io.h>
#include <util/delay.h>
#include <util/atomic.h>
#include "avros.h"

#define TIMER_PRESCALER  64
#define TIMER_MICROS(ps) ((ps) * 1000000 / F_CPU)
#define TIMER_COUNT(us)  ((us) / TIMER_MICROS(TIMER_PRESCALER))
#define TIMER_MILLIS     TIMER_COUNT(1000)
#define TIMER_WAIT_MIN   (uint8_t)(120 * F_CPU / 16000000) // minimum limit
#define TIMER_WAIT_PTC   (uint8_t)( 78 * F_CPU / 16000000) // processing time correction

#if defined(TIMSK)
  #define TIMSK0 TIMSK
#endif
#if defined(TIFR)
  #define TIFR0 TIFR
#endif

static volatile uint32_t    _micros;
static volatile uint32_t    _millis;
static uint32_t             _ovfcnt;
static SEQUE(TASK_T, timer) _queue;

#define TIMER_ISR_CLOCK() \
  do \
  { \
    OCR0A += TIMER_MILLIS; \
    _micros += 1000; \
    _millis += 1; \
  } \
  while (0)

ISR(TIMER0_COMPA_vect)
{
  TIMER_ISR_CLOCK();
}

uint32_t Timer::clock(bool us)
{
  uint32_t m;
  uint8_t  c, t;
  do
  {
    // nointerrupts ?
    if (TIFR0 & _BV(OCF0A))
    {
      TIFR0 |= _BV(OCF0A);
      TIMER_ISR_CLOCK();
    }
    // read counter
    t = OCR0A;
    c = TCNT0;
    m = us ? _micros : _millis;
  }
  while ((t != OCR0A) || (TIFR0 & _BV(OCF0A)));
  return us ? m + ((uint8_t)(TIMER_MILLIS - 1) - (uint8_t)(t - c)) * TIMER_MICROS(TIMER_PRESCALER) : m;
}

void timer0_compb_vect(void)
{
  Timer::timer0_compb_vect();
}

ISR(TIMER0_COMPB_vect)
{
  timer0_compb_vect();
}

bool Timer::wakeup_match(TASK_T *task, uint32_t time)
{
  time = task->x.time - time;
  if ((int32_t)time > 0)
  {
    init(TIMER_COUNT(time));
    return false;
  }
  if (task->wait)
    task->wait->timeout(task);
  task->wcode = WAIT_TIMEOUT;
  Task::enqueue(task);
  return true;
}

void Timer::timer0_compb_vect(void)
{
  if (_ovfcnt > 2)
    _ovfcnt -= 2;
  else if (--_ovfcnt)
    OCR0B += 0x80;
  else
  {
    if (_queue.removeUntil<uint32_t>(wakeup_match, micros()))
      TIMSK0 &= ~_BV(OCIE0B);
    Task::switching();
  }
}

void Timer::init(int32_t count)
{
  if (--count < 2)
    count = 2;
  _ovfcnt = ((count >> 8) << 1) | ((uint8_t)count & 0x80 ? 1 : 0);
  if (_ovfcnt)
    OCR0B = TCNT0 + ((uint8_t)count | 0x80);
  else
  {
    *((uint8_t *)&_ovfcnt) = 1;
    OCR0B = TCNT0 + (uint8_t)count;
  }
}

void Timer::restart(uint32_t time)
{
  init(TIMER_COUNT((int32_t)(time - micros())));
  TIFR0  |= _BV(OCF0B);
  TIMSK0 |= _BV(OCIE0B);
}

bool Timer::insert_match(TASK_T *task, uint32_t time)
{
  return (int32_t)(task->x.time - time) > 0;
}

void Timer::setup(TASK_T *task, int32_t timeout, Timer *wait)
{
  if (timeout <= 0)
    task->wait = nullptr;
  else
  {
    task->wait   = wait;
    task->x.time = micros() + timeout - TIMER_WAIT_PTC;
    if (_queue.insert<uint32_t>(task, insert_match, task->x.time) == QUEUE_STATUS_FIRST)
      restart(task->x.time);
  }
}

void Timer::cansel(TASK_T *task)
{
  if (task->wait)
  {
    task->wait = nullptr;
    if (_queue.remove(task) == QUEUE_STATUS_FIRST)
    {
      TASK_T *task = _queue.head();
      if (task)
        restart(task->x.time);
    }
  }
}

void Timer::begin(void)
{
  TCCR0A = 0; // standard mode. (not pwm mode)
  OCR0A  = TCNT0 + TIMER_MILLIS - 1;
  TIFR0  |= _BV(OCF0A);
  TIMSK0 |= _BV(OCIE0A);
  // start timer. if not started.
  if ((TCCR0B & (_BV(CS02) | _BV(CS01) | _BV(CS00))) == 0)
    TCCR0B = _BV(CS01) | _BV(CS00); // 1/64
}

uint32_t Timer::micros(void)
{
  return clock(true);
}

uint32_t Timer::millis(void)
{
  return clock(false);
}

void Timer::delay(int32_t ms)
{
  delayMicroseconds(ms * 1000);
}

void Timer::delayMicroseconds(int32_t us)
{
  if (us >= TIMER_WAIT_MIN)
  {
    ATOMIC_BLOCK(ATOMIC_RESTORESTATE)
    {
      TASK_T *task = Task::dequeue();
      if (task)
      {
        setup(task, us, nullptr);
        Task::switching();
      }
    }
  }
  else if (us > 0)
    _delay_loop_2(us * (F_CPU / 4000000));
}

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timer.cpp - Timer Function Class

This library is free software; you can redistribute it and/or

modify it under the terms of the GNU Lesser General Public

License as published by the Free Software Foundation; either

version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General

Public License along with this library; if not, write to the

Free Software Foundation, Inc., 59 Temple Place, Suite 330,

Boston, MA 02111-1307 USA

#include <stdint.h>

#include <stdbool.h>

#include <avr/io.h>

#include <util/delay.h>

#include <util/atomic.h>

#include "avros.h"

#define TIMER_PRESCALER 64

#define TIMER_MICROS(ps) ((ps) * 1000000 / F_CPU)

#define TIMER_COUNT(us) ((us) / TIMER_MICROS(TIMER_PRESCALER))

#define TIMER_MILLIS TIMER_COUNT(1000)

#define TIMER_WAIT_MIN (uint8_t)(120 * F_CPU / 16000000) // minimum limit

#define TIMER_WAIT_PTC (uint8_t)( 78 * F_CPU / 16000000) // processing time correction

#if defined(TIMSK)

#define TIMSK0 TIMSK

#endif

#if defined(TIFR)

#define TIFR0 TIFR

#endif

static volatile uint32_t _micros;

static volatile uint32_t _millis;

static uint32_t _ovfcnt;

static SEQUE(TASK_T, timer) _queue;

#define TIMER_ISR_CLOCK() \

do \

{ \

OCR0A += TIMER_MILLIS; \

_micros += 1000; \

_millis += 1; \

} \

while (0)

ISR(TIMER0_COMPA_vect)

{

TIMER_ISR_CLOCK();

}

uint32_t Timer::clock(bool us)

{

uint32_t m;

uint8_t c, t;

{

// nointerrupts ?

if (TIFR0 & _BV(OCF0A))

{

TIFR0 |= _BV(OCF0A);

TIMER_ISR_CLOCK();

}

// read counter

t = OCR0A;

c = TCNT0;

m = us ? _micros : _millis;

}

while ((t != OCR0A) || (TIFR0 & _BV(OCF0A)));

return us ? m + ((uint8_t)(TIMER_MILLIS - 1) - (uint8_t)(t - c)) * TIMER_MICROS(TIMER_PRESCALER) : m;

}

void timer0_compb_vect(void)

{

Timer::timer0_compb_vect();

}

ISR(TIMER0_COMPB_vect)

{

timer0_compb_vect();

}

bool Timer::wakeup_match(TASK_T *task, uint32_t time)

{

time = task->x.time - time;

if ((int32_t)time > 0)

{

init(TIMER_COUNT(time));

return false;

}

if (task->wait)

task->wait->timeout(task);

task->wcode = WAIT_TIMEOUT;

Task::enqueue(task);

return true;

}

void Timer::timer0_compb_vect(void)

{

if (_ovfcnt > 2)

_ovfcnt -= 2;

else if (--_ovfcnt)

OCR0B += 0x80;

else

{

if (_queue.removeUntil<uint32_t>(wakeup_match, micros()))

TIMSK0 &= ~_BV(OCIE0B);

Task::switching();

}

void Timer::init(int32_t count)

{

if (--count < 2)

count = 2;

_ovfcnt = ((count >> 8) << 1) | ((uint8_t)count & 0x80 ? 1 : 0);

if (_ovfcnt)

OCR0B = TCNT0 + ((uint8_t)count | 0x80);

else

{

*((uint8_t *)&_ovfcnt) = 1;

OCR0B = TCNT0 + (uint8_t)count;

}

void Timer::restart(uint32_t time)

{

init(TIMER_COUNT((int32_t)(time - micros())));

TIFR0 |= _BV(OCF0B);

TIMSK0 |= _BV(OCIE0B);

}

bool Timer::insert_match(TASK_T *task, uint32_t time)

{

return (int32_t)(task->x.time - time) > 0;

}

void Timer::setup(TASK_T *task, int32_t timeout, Timer *wait)

{

if (timeout <= 0)

task->wait = nullptr;

else

{

task->wait = wait;

task->x.time = micros() + timeout - TIMER_WAIT_PTC;

if (_queue.insert<uint32_t>(task, insert_match, task->x.time) == QUEUE_STATUS_FIRST)

restart(task->x.time);

}

void Timer::cansel(TASK_T *task)

{

if (task->wait)

{

task->wait = nullptr;

if (_queue.remove(task) == QUEUE_STATUS_FIRST)

{

TASK_T *task = _queue.head();

if (task)

restart(task->x.time);

}

void Timer::begin(void)

{

TCCR0A = 0; // standard mode. (not pwm mode)

OCR0A = TCNT0 + TIMER_MILLIS - 1;

TIFR0 |= _BV(OCF0A);

TIMSK0 |= _BV(OCIE0A);

// start timer. if not started.

if ((TCCR0B & (_BV(CS02) | _BV(CS01) | _BV(CS00))) == 0)

TCCR0B = _BV(CS01) | _BV(CS00); // 1/64

}

uint32_t Timer::micros(void)

{

return clock(true);

}

uint32_t Timer::millis(void)

{

return clock(false);

}

void Timer::delay(int32_t ms)

{

delayMicroseconds(ms * 1000);

}

void Timer::delayMicroseconds(int32_t us)

{

if (us >= TIMER_WAIT_MIN)

{

ATOMIC_BLOCK(ATOMIC_RESTORESTATE)

{

TASK_T *task = Task::dequeue();

if (task)

{

setup(task, us, nullptr);

Task::switching();

}

else if (us > 0)

_delay_loop_2(us * (F_CPU / 4000000));

}

月: 2021年2月

理想のＲＴＯＳを自作する (5)