MQX Idle task and Low power question

tybos — Wed, 04 Dec 2013 16:33:20 GMT

Hi Freescale Community,

I recently managed to run MQX (4.0.2) on a custom board based on K10 (50 MHz silicon) device.

This board is dedicated to measuring chip consumption so I wanted to activate Low Power mode for MQX.

Looking at Idle task code and mqx.h, I found something that doesn't seem to make sense.

In src/include/mqx.h (line 162):

#define MQX_IDLE_TASK_PARAMETER 0

#if (MQX_USE_IDLE_TASK) && (MQX_ENABLE_LOW_POWER) && (MQX_IDLE_TASK_PARAMETER != 0)

#error MQX_IDLE_TASK_PARAMETER must be 0 when Low Power feature is enabled!

#endif

And in src/kernel/idletask.c:

void _mqx_idle_task

    (

        uint_32 parameter

    )

{ /* Body */

    [...]

    while (1) {
          [...]
     #if MQX_ENABLE_LOW_POWER
        if (parameter)

        {

            _ASM_SLEEP();

        }

     #endif

    } /* Endwhile */

} /* Endbody */

If I understand this well, mqx.h forces me to let MQX_IDLE_TASK_PARAMETER to 0 while idle task will test this parameter to be not 0 to enter wait mode.

So basically, I can not enter wait mode in idle task unless I modify idletask.c.

Do I miss something here ?

Thank you in advance for those who will read and discuss this point.

Tybos

Re: MQX Idle task and Low power question

tybos — Thu, 05 Dec 2013 09:15:38 GMT

Looking at mqx/examples/lowpower, everything makes sense !

Low power driver (io/lpm/lpm.c) defines a routine

_mqx_uint _lpm_idle_sleep_setup

    (

        /* [IN] Whether to turn on/off the idle sleep feature */

        boolean idle_sleep

    )

that restarts Idle task (if needed) with updated parameter.

I only need to call _lpm_idle_sleep_setup(TRUE) at beginnning of my task to allow entering wait mode.

MQX Software SolutionsのトピックMQX Idle task and Low power question

MQX Idle task and Low power question

Re: MQX Idle task and Low power question