Re: [avr-libc-dev] Optimization safe access to the timers

[Paulo Marques]

Enoch H. Wexler wrote:
> Hello libc maintainers,

Hi, Enoch.

Not a libc maintainer, more of a lurker, but maybe I can help ;)

> May I suggest adding to libc an optimization safe access method to the
> timers, for example:
>
> typedef volatile int16_t (*pTCNT);
> #define TCNT(n) *(pTCNT)(&TCNT ## n) /* e.g., TCNT(3) */
>
> Without this a 100 "tick" delay loop like this would run forever:

Have you verified this?

It shouldn't run forever since TCNT3 should already be declared as 
volatile, like all the hardware registers that can change value without 
the compiler knowing.

If for some reason it is not declared volatile, that would be a bug.

--
Paulo Marques