I wish there was more detailed technical information on the page. I've been trying to figure out how precise the timer is, or at what frequency you can read from the pins. The answer seems to be provided on pages 112+ in the datasheet of the micro controller, but in a not very easy to understand format for the aspiring programmer without EE knowledge.
http://www.st.com/web/catalog/mmc/FM141/SC1169/SS1577/LN1035...