This question is a variation of How to trigger reset at long press of button.
Namely, I need to pull down a reset line with a short pulse of X length, if a button is pressed for Y>=X or more seconds. To be clear, I need for the reset line to go low for X seconds and then go up again without having to depress the button (this is different to the cited question, since I can't rely on the button being depressed for the signal to go up again).
To give some example values here, suppose I want to bring the reset line to low for 5uS if a button is pressed for 5 seconds or more. It is acceptable if the this 5uS pulse gets generated every 5 seconds for as long as the button remains pressed (i.e. a pulse train), but generating a single pulse is all I really need.
One way to achieve this would be using a pulse generator IC, or other specialized IC's. However, ideally I would like to do it using only simpler components (Rs, Cs and perhaps a transistor or mosfet if required).