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CMSIS-RTOS time slice: Is any way to use ticks or microseconds

W L

Hi,

I want to use STM32427 instead of STM32407, but uVision V4 doesn't supports that chip.
So I upgrade uVision from V4 to V5, and plan to use CMSIS-RTOS RTX instead of RTX.

But now I have some questions after read the paper named "Migrate RTX to CMSIS-RTOS":

1.How can I delay a thread or pend a semphone less then 1ms?
(I have a thread need to do periodic things and pend some thread messages, so the timeout should less then 1ms)

2.If CMSIS-RTOS RTX doesn't support, can I still use RTX on STM32M427 by uVision V5, is there any problem?

Thanks!
Best regards

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  • 0 in reply to Makoto K

    Thanks for your reply!
    Yes, it work when I used the old RTX.
    I set OS_TICK value to 10[us] and used rt_dly_wait function to delay faster than 1000[us]:

    void rt_dly_wait(U16 delay_time)


    But now if I use the new API in CMSIS-RTOS:

    osStatus osDelay(uint32_t millisec)

    it can't delay faster then 1000[us].


    Because in rt_CMSIS.c, it defined the generic wait function:

    SVC_1_1(svcDelay, osStatus, unit32_t, RET_osStatus)

    the svcDelayy called rt_dly_wait(rt_ms2tick(millisec)) to implemented the time delay.
    The rt_ms2tick function convent timeout in millisec to system ticks:

    static uint32_t rt_ms2tick(uint32_t millisec){
 uint32_t tick;
 ...//some if conditions
 tick = ((1000*millisec) + os_clockrate -1) / os_clockrate;
 ...//
 return tick;
}

    I dont't think use this osDelay function can delay faster then 1000[us].


    So if I want to dealy faster then 1000[us], do I have to use old RTX API and include RTL.H instead of cmsis_os.h ?

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  • 0 in reply to Makoto K

    Thanks for your reply!
    Yes, it work when I used the old RTX.
    I set OS_TICK value to 10[us] and used rt_dly_wait function to delay faster than 1000[us]:

    void rt_dly_wait(U16 delay_time)


    But now if I use the new API in CMSIS-RTOS:

    osStatus osDelay(uint32_t millisec)

    it can't delay faster then 1000[us].


    Because in rt_CMSIS.c, it defined the generic wait function:

    SVC_1_1(svcDelay, osStatus, unit32_t, RET_osStatus)

    the svcDelayy called rt_dly_wait(rt_ms2tick(millisec)) to implemented the time delay.
    The rt_ms2tick function convent timeout in millisec to system ticks:

    static uint32_t rt_ms2tick(uint32_t millisec){
 uint32_t tick;
 ...//some if conditions
 tick = ((1000*millisec) + os_clockrate -1) / os_clockrate;
 ...//
 return tick;
}

    I dont't think use this osDelay function can delay faster then 1000[us].


    So if I want to dealy faster then 1000[us], do I have to use old RTX API and include RTL.H instead of cmsis_os.h ?

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