eFuse

In computing, an eFuse (electronic fuse) is a microscopic fuse put into a computer chip. This technology was invented by IBM in 2004^[1] to allow for the dynamic real-time reprogramming of chips. In the abstract, computer logic is generally "etched" or "hard-wired" onto a chip and cannot be changed after the chip has finished being manufactured. By utilizing a set of eFuses, a chip manufacturer can allow for the circuits on a chip to change while it is in operation.^[2]

eFuses can be made out of silicon or metal traces. In both cases, they work (blow) by electromigration, the phenomenon where electric flow causes the conductor material to move. Although electromigration is generally undesired in chip design as it causes failures, eFuses are made of weak traces that are designed to fail before others do.^[3][4]

• 
  Intact fuse
• 
  Blown fuse

eFuses were initially marketed by IBM as a way to provide in-chip performance tuning. If certain sub-systems fail, or are taking too long to respond, or are consuming too much power, the chip can instantly change its behavior by blowing an eFUSE.^[3][5][6] Today, most eFuses are used to etch serialization or calibration data onto a chip thus making it a read-only value.^[7]

eFuses are perhaps more commonly used as a one-time programmable ROM or write-restricted memory, and not actual physical electric fuses. This ranges from writing unique information onto CPUs,^[4] or in the case of game consoles and other restricted hardware, preventing downgrades by permanently recording a newer version. The Xbox 360, Nintendo Switch, Pixel 6 and Samsung Galaxy S22 are known for using eFuses this way.^[8]

eFuses used for performance adjustment or unique IDs:

• IBM POWER5 and POWER6 high-end RISC processors; probably all newer models^[3]
• IBM System z9 and System z10mainframe processors^[9]
• Sony/Toshiba/IBM Cell used in PlayStation 3. Not claimed to be used for downgrade prevention.
• Procesadores Intel Westmere ; probablemente todos los modelos más recientes ^{[ 4 ]}
• Familia de microcontroladores TI MSP430 para identificadores únicos.
• SERDES TI FPD-Link para una variedad de configuraciones diferentes.

Fusibles electrónicos conocidos por utilizarse para la restricción de hardware:

• CPU IBM/Microsoft Xenon en la consola de juegos Xbox 360.  768 bits de fusibles. ^{[ 10 ] [ 11 ] [ 12 ]}
• Los dispositivos Samsung Knox utilizan un eFuse para detectar si alguna vez se ha ejecutado una ruta de arranque que no sea de Samsung. ^{[ 13 ]}

Los eFuses rearmables se utilizan para proteger circuitos. Funcionan de forma similar a los fusibles rearmables y, por lo general, se envían como un paquete de chip independiente. ^{[ 14 ]}

Hay varias formas de implementar un antifusible en silicio: véase Antifusible §  Antifusibles en circuitos integrados .

• Antifusible
• Computación reconfigurable