I was trying to understand how the Arduino's original reset circuit worked so I could get a better grasp on why it was changed and how those changes affected the behavior of it, when I found this thread: http://www.adafruit.com/forums/viewtopic.php?f=25&t=42192
It mentioned that the voltage would jump up to 10V when DTS went high again. Come again?
I decided to simulate the circuit, and I confirmed it was true:
But I don't understand what's going on.
When I flip the DTS to high, both sides of the capacitor are at 5V. When I flip it to low, the voltage on the reset line drops to 0V momentarily, then rises back to 5V. The side of the capacitor connected to it is now at 5V, and the side connected to DTS is at 0V. So far so good. The capacitor is charged.
But when I flip DTS back to high, the reset line jumps to 10V. I'm having a hard time grasping why that happens.