I need to simulate realistic button presses that include bounce patterns..but digitally with something like an FPGA to test my debouncing code. How do I generate those noises?
The press of a button is not really noise, they are mostly at the logic level of either 0V and VDD.
When bounce occurs, it would bounce a few times between VDD and GND, but there is not really much transient noise, or they appear because of the acquisition speed of the oscillo.
You can take a button and record a few presses on an oscilloscope, and then program the pattern in your FPGA.
If you really want to make transient peaks, you can add a small cap on the line and generate very short pulses.