Understanding HPET main counter value

[kurtmweber]

I can't find anything that states this unambiguously in the documentation, unless I've missed it (which is entirely possible), but:

Does an increment of 1 in the HPET main counter value represent (at least in principle, because obviously the reality of clock implementations is constrained by physical uncertainty and tolerances and resolution, etc.) the passage of:

1 femtosecond

1 "General Capabilities and ID Register"->"COUNTER_CLK_PERIOD"

Something else

?

[nullplan]

That is precisely what "period time" means. So option number two!