SWD

In one of my old text books there was a quote from Andrew Tanenbaum saying, "The nice thing about standards is that you have so many to choose from". The common JTAG/SWD debug connector is this one:

 

 As you can see it is pretty small when you compare it with the older 0.1" spacing connector to the right of it. I am not a fan of these connectors as I have bent them and they are plain fiddly. However they do take up less real-estate that the old ARM JTAG that is 2 x 10 0.1" pins.

I have a Seed Studio ARM board that uses a 2 x 3, 0.1" header for the SWD (all that you really need these days) in the same pin allocation as the AVR8 Atmel Debug/Programming header. This, I thought, made a lot of sense and is pretty easy to use. This has become my new standard for ARM SWD as well.