As David Johnson-Davies notes in his newest Technoblogy write-up: Should you’re designing an AVR venture and also you want just a few buffers or inverters, you’ll be able to add a CMOS gate bundle to your circuit. Whereas not an enormous deal hardware-wise, because it seems you’ll be able to as a substitute resolve this problem utilizing the microcontroller itself by way of the AVR Occasion System. That is reportedly an under-appreciated side of AVR microcontrollers, possible as a result of it’s considerably unintuitive to make use of. I’d additionally argue that many individuals, together with myself, have by no means heard of it.
Utilized or not, the Occasion System was launched within the ATtiny 1-series processors and has been part of all AVR processors launched since then. There are three variations accessible, and Johnson-Davies offers with V2 and three, which characteristic a variety of enhancements over the unique. Lengthy story brief, the Occasion System successfully means that you can shortcut leads between inputs and outputs, creating performance – i.e. logic gates – that work independently of the traditional processing paradigm, exterior of even the processor’s clock pace.
Johnson-Davies’ weblog publish offers tons extra element, together with hyperlinks to reference materials. He additionally offers a number of concrete examples of what you are able to do with these gates, substituting AVR-generated inverters and an AVR-generated buffer to kind a blink circuit (in two completely different configurations). He then outlines the right way to make a pushbutton debouncer with this logic circuitry, which may maybe be a extra sensible software.
With this “whats up world” gate performance understood on a primary stage, one may see it utilized to a variety of purposes. It is a resolution ready for the correct drawback. Should you don’t see a use for it now, it’s one thing you may wish to hold in your psychological electronics toolbox for simply the correct circumstance!