[avr-chat] using input capture on tiny2313

[Bjarne Laursen]

Hej.
I am developing a modem for the tiny2313 and I would like to use the 
input capture of timer1.
I wan't to record any change of the the input, so in each interrupt I 
will be inverting the edge bit, ICES1. The datasheet state that, after 
doing this I must clear any pending capture interrupts. I can't see why 
this is nessesary. If the ICES1 bit is xor'ed with the input, there will 
not be generated any extra interrupts at this point. Actually I would 
like an interrupt to be generated if the input has already changed back.

My hardware is not ready yet, so can't try it out. Also, I don't like 
trial and error, escpecially not when it goes against the datasheet.
The datasheet does not clearly state that the ICES1 bit goes into an 
xor-gate.

Do you have any experience with that ?


-Bjarne Laursen, Rose Technology A/S, Denmark