pulse function

I am trying to set up my arduino to read frequency from a function generator and display it on an lcd and want to use the pulse function. the outputs are square, triangle and sine. how would I go about interfacing the frequency and writing code? I tried the reference on this site but dont understand it. can someone help me?

Have a look at this thread:- http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1231326297 you don't say what range of frequencies you want to measure and how often you want to refresh. These things matter.

the range of frequencies is 1hz to 1Mhz and fine tuning with a potentiometer

at 6 switchable settings 1hz, 100hn, 1k, 10k 100k, 1M

At frequencies below 1KHz I would go for timing the pulse period. Above that I would use the counting pulses in a fixed period.

Can I do that without another circuit and just use the arduino? if not what circuits

also I am using an ATmeg328 can this be used for that?