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delay milisecond

Hi all Iam using STR912FW44 based board and I want a delay function that should give the delay in milisecond I made a function


void delay_ms (unsigned long nCount){   /* Wait function                    */
  nCount=nCount+16000000L;

  while (nCount--);
}

when I call

delay_ms(10000);

it gives arround 10 second delay but when I call

delay_ms(20000);
it should give arround 20 second delay but it does not happen

but when I call

delay_ms(10000);
delay_ms(10000);

it gives arround 15 sec delay

please tell me exact way to build a delay function

regards
rupesh

Parents

0 Catcus Blip over 16 years ago

// this system call is an asynchronous call that is used to register a callback for exact
// time-based notifications. any timer can serve as either in 'exact' mode or in 'poll'
// mode.
// 'a_index' if the index of the timer in 's_timers', a_timoeut should be given
// using the MILLISECONDS_X_10 macro, 'a_timer' is a struct that contains a pointer to a
// callback that shall be invoked once the timer elapses and the required parameter to be
// send alog, and 'a_mode' is the timer more - must be either 'e_timer_exact_period_mode' or
// 'e_timer_exact_oneshot_mode' when using the system call.
// note that the first 1 + MAX_TASKS timers are dedicated to internal timers of tasks, and
// should not be used for any other purpose. user timers having an index USER_TIMER_0,
// USER_TIMER_1 etc. should be used instead.
int32s timer_exact(int32s a_index, int32s a_timeout, timer_callback_prop_t a_timer, timer_mode a_mode)
{
        int32u   l_scheduler_state ;
        timer_t *lp_timer ;

        if ( (a_timeout < 0) ||
                 (!a_timer.callback) ||
                 ( (a_mode != e_timer_exact_period_mode) && (a_mode != e_timer_exact_oneshot_mode) ) )
        {
                software_error("%d %s %d", ERR_INVALID_PARAMETER, __FILE__, __LINE__) ;
        }

        scheduler_disable(&l_scheduler_state) ;
        system_timer_disable() ;

        lp_timer = (s_timers + a_index) ;
        lp_timer->state = e_timer_ticking ;
        lp_timer->deadline_countdown = a_timeout ;
        lp_timer->period = a_timeout ;
        lp_timer->callback = a_timer.callback ;
        lp_timer->callback_parameter = a_timer.parameter ;
        lp_timer->mode = a_mode ;

        system_timer_enable() ;
        scheduler_restore(l_scheduler_state) ;

        return 0 ;
}

Reply

0 Catcus Blip over 16 years ago

// this system call is an asynchronous call that is used to register a callback for exact
// time-based notifications. any timer can serve as either in 'exact' mode or in 'poll'
// mode.
// 'a_index' if the index of the timer in 's_timers', a_timoeut should be given
// using the MILLISECONDS_X_10 macro, 'a_timer' is a struct that contains a pointer to a
// callback that shall be invoked once the timer elapses and the required parameter to be
// send alog, and 'a_mode' is the timer more - must be either 'e_timer_exact_period_mode' or
// 'e_timer_exact_oneshot_mode' when using the system call.
// note that the first 1 + MAX_TASKS timers are dedicated to internal timers of tasks, and
// should not be used for any other purpose. user timers having an index USER_TIMER_0,
// USER_TIMER_1 etc. should be used instead.
int32s timer_exact(int32s a_index, int32s a_timeout, timer_callback_prop_t a_timer, timer_mode a_mode)
{
        int32u   l_scheduler_state ;
        timer_t *lp_timer ;

        if ( (a_timeout < 0) ||
                 (!a_timer.callback) ||
                 ( (a_mode != e_timer_exact_period_mode) && (a_mode != e_timer_exact_oneshot_mode) ) )
        {
                software_error("%d %s %d", ERR_INVALID_PARAMETER, __FILE__, __LINE__) ;
        }

        scheduler_disable(&l_scheduler_state) ;
        system_timer_disable() ;

        lp_timer = (s_timers + a_index) ;
        lp_timer->state = e_timer_ticking ;
        lp_timer->deadline_countdown = a_timeout ;
        lp_timer->period = a_timeout ;
        lp_timer->callback = a_timer.callback ;
        lp_timer->callback_parameter = a_timer.parameter ;
        lp_timer->mode = a_mode ;

        system_timer_enable() ;
        scheduler_restore(l_scheduler_state) ;

        return 0 ;
}

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