Spartan UltraScale+ FPGA eFUSEs are nonvolatile one-time-programmable (OTP) cells used for select device settings and user-programmable elements including:
- Programmable device image (PDI) key storage
- AES-GCM encryption key
- Authentication key hash
- Factory-programmed Device DNA (96-bits)
- User 32-bit value (
EFUSE_USRprimitive) - Control and security settings
The fuse link is programmed (burned or blown) by flowing a large
current for a specific amount of time. The resistance of a programmed fuse link is
typically a few orders of magnitude higher than that of a pristine or unprogrammed
fuse. A programmed fuse is assigned a logic value of 1, and a pristine fuse has a logic value of 0.