AVR-Chat

--- In AVR-Chat@yahoogroups.com, John Samperi <samperi@a...> wrote:
> Have we strayed enough away from the original topic
> yet or shall we do a bit more? :-)

A topic that is at least tangentially related to the concepts of logic 
polarity and logic thresholds is that of "active level".  A signal can 
be "active high" or "active low".  The usual assumption is that a 
signal, when asserted, goes to the logic 1 level - that is the meaning 
of active high.

In some cases, it is more convenient to design a circuit so that the 
signal goes to logic 0 when asserted, i.e. it is active low.  It is 
usually a good idea to denote on a schematic that a signal is active 
low by adding a slash at the beginning or end of its name.  A trailing 
asterisk is also used for this purpose sometimes.  An example of a 
signal that is typically active low is RESET/.