Re: uhh...
TKS said:
let's say i use
1 16F877a
or 9 16F877a
i don't care..
i only need to know if it can handle the pulses on the i/o lines
in that way that i canmeasure the time between the pulses
and i can know on which line it was...
TKS
You need to give more details of your requirements, presumably (from what you've already said) you are effectively wanting to measure the frequency of the pulses - but as it's a low frequency, you are planning measure the time for one cycle, and calculating the frequency from that. This is a standard way of measuring low frequencies.
It's quite simple to do totally in software, there's no need for timers, simply follow these steps:
1) Test the port pin, and wait until it's low.
2) Wait until the port pin goes high - start of cycle.
3) Increment a software counter, use as many bytes as you need for the resolution you require.
4) Check if port is low again, if not go back to 3).
5) Increment the software counter again.
6) Check if port if high again, if not go back to 5).
7) End of routine, software counter holds a representation of the width of one cycle.
This will only work for one input pin at a time, for more than one input pin you would need to measure then in turn - if the pulses appear at random intervals, on random pins, it gets a lot more difficult.
So please give more details of what you are trying to do!.