Arduino reset schematic - I don't get it

The solder bridge and the 100nF reset cap.

I've asked about this before and been told that you short the bridge if you don't want the reset function. That's fair enough and I'm sure that's how it works on a PCB, but the schematics for all Arduinos show this in slightly different forms

I didn't get it with the Duemilanove, I didn't get it with the Mega1280, and now I don't get it with the Mega2560.

This depicts a trace that is optionally in parallel with another trace. If we are talking about high current or high frequency the actual trace layout is important and maybe there would be something else at play here, but not for a reset signal.

So at the risk of making a complete prat of myself (not for the first time and probably not the last), I don't get it. Can someone explain?


I look at this affordance the following way: I can disable auto-reset by cutting or gouging the pre-wired trace. I can later re-enable it by blobbing the provided solder pads, or just shorting them with tweezers.

Does that help?


Aah thankyou, that makes sense.

I get it :)