I am working on a project dealing with home security.
What I'd like to change is my dtmf storage area. what I am using right now is a recording chip ISD1420 would like to use some form of ram. I am not using microprosseror but I am confused on what is needed. Do I have to use addressable latches, multiplexers,channel data-selector, shift and store bus register. any help would be great. Having hard time finding good information on how it all works.