Hi Erik,

it is absolute necessary to serve potential overflows near reading the low bytes !

With clearing and reading simultaneous it is guaranteed, that the overflow flag was set only before any reading, because after clearing it need 256 cycle until the next overflow.

Without it you would get flickering readings !

Furthermore the priority changing was needed to cause, that all overflows are handled prior reading the high bytes and thus the low and high bytes are always in phase.


Also reading a timer on the fly contain no problems, but allow consecutive measurements. No special synchronization routine was needed.


Maybe there exist also a many more complicated way to do so completely in C.


Peter