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Re: HAL_DELAY_US()


Øyvind Harboe wrote:
Going through my changes to eCos, I ran into HAL_DELAY_US().

Does this function belong in the application or eCos?

If it can be implemented in a correct manner that does not require any
configuration, then I believe it belongs in the HAL.

If it needs to be tuned to the hardware in question, then I believe it
belongs in the application space.

The implementation in EB40a is busted because it is not
multithreading/interrupt safe.


Ref. earlier discussions HAL_DELAY_US() should take *at least* that many us, there is no upper limit or requirement on precision as such.

IMO, HAL_DELAY_US() should not be used if interrupts or thread switches can cause a perturbation. It's *only* function is to provide very simple timing when devices require it. It should not be used for arbitrary delays, certainly not in user/application code. For that, use 'cyg_thread_delay()'

--
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Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
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