An FPGA core for glitching circuits, written with Amaranth HDL.
Note: This introduction assumes you already know what "voltage glitching"/"voltage fault injection" is.
glitchcore is a system designed to facilitate glitching by counting a configurable number of "events" (changes in voltage from high to low or low to high), waiting for a configurable period of time, and then transmitting a voltage pulse with a configurable width. Each parameter is configurable at run-time, either directly via the signals in each module or via a Wishbone interface. A simplified (and slightly outdated) schematic of glitchcore can be seen below:
Unlike some other FPGA-based glitching cores, glitchcore does not have any pattern-matching functionality. Instead, only an event counter is provided, and if higher-level matching is desired (e.g., matching on UART/SPI/I2C data), the event counter can be bypassed and the output of an external pattern-matching core (or microcontroller) can be connected directly to the delay trigger input instead.