Originally published on the old depletionmode / 2of1 blog (archived copy).
I finally got around to working on a project that I've been wanting to do for quite a while.
Introducing the GlitchMeister 1.0....
It's basically a Simple, Stupid FPGA-based glitcher (something along the lines of the PS3 Glitch Finder with a few notable differences) but I wanted to do one myself as my FPGA skills are getting rusty (excuse the code quality; - or lack thereof).
You can download the Quartus II project w/ the VHDL code from the Github here.
I developed it for my Terasic DE0 dev board (Altera Cyclone III) but it's around 200 LEs so pretty much any hardware will do.
Features:
- Minimum pulse length = 10ns (driven off a 100MHz PLL)
- Configurable 8-bit multiplier (max pulse length = 10ns x 255 = 2.55us)
- Configurable direction (high/low)
- Glitch driven from high-impedance state
- Glitch driven by push-button or active-low GPIO pin
- 8-bit glitch counter
Here's a video walking through how it works: