Hi everyone,
I think everyone agrees that if a relative timer is set, it is expected
to run *at least* the amount of time that is specified as interval to
timer_set().
That means if now() is e.g., 0 ticks and the timer is set to wait 1
tick, the timer must trigger at 2 ticks, as even if now()==0, the actual
("real") time is anywhere between ticks 0 and 1.
If ticks where 1ms each and now_us() is actually 999 (one us before
now()==1), triggering at now(1) would trigger only 1us later and not
1ms. Thus it needs to trigger at 2 ticks (2ms), in order to have the
timer wait "at least 1ms". Correct so far?
Now for the case where a 1ms timer is using a 1us timer as backend.
If a 1ms timer is set at now_ms()==0 and now_us()=500 to trigger after
1ms, it would be possible to trigger the timer at now_ms()==1 and
now_us()==1500, thus at a "half_tick" of now_ms(). Should that be done,
or should the conversion be implemented in a way that the 1ms timer
behaves the same regardless of the lower timer having 1ms or 1us precision?
Kaspar
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