eFuse
 | This article includes a list of general references, but it lacks sufficient corresponding inline citations. (September 2008) |
In computing, eFuse is a technology invented by IBM which allows for the dynamic real-time reprogramming of computer chips. Speaking abstractly, computer logic is generally "etched" or "hard-coded" 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.
The primary application of this technology is 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.
Another use is to prevent downgrading the firmware of a device. The Nintendo Switch and Xbox 360's bootloaders for instance will check the amount of burned fuses before attempting to install new firmware[1]. The amount of fuses expected to be burnt depends on the hardware model and the firmware to be installed. If too many fuses are burnt (meaning the firmware to be installed is older than the current firmware) the bootloader will panic, preventing installation. After successfully installing a new firmware version, the system will burn the required amount of fuses to match the new expected amount.
Implementations
- IBM POWER5 and POWER6 high-end RISC processors
- IBM System z9 and System z10 mainframe processors
- Sony/Toshiba/IBM Cell used in PlayStation 3
- IBM/Microsoft Xenon CPU in the Xbox 360 game console.
- In the Nintendo Switch's bootloader [1]
- TI OMAP3-based mobile phones and other devices[2][3]
- Samsung KNOX-enabled devices (KNOX warranty void bit)[4]
See also
References
- ^ a b "Fuses - Nintendo Switch Brew". switchbrew.org. Retrieved 2017-08-03.
- ^ "Overview - Processors - TI.com". focus.ti.com.
- ^ "Motorola responds to Droid X bootloader controversy, says eFuse isn't there to break the phone".
- ^ "Archived copy". Archived from the original on 2015-10-29. Retrieved 2015-09-16.
{{cite web}}: Unknown parameter|deadurl=ignored (|url-status=suggested) (help)CS1 maint: archived copy as title (link)
General
- "IBM introduces chip morphing technology". IBM. 2004-07-30. Retrieved 2009-09-17.
- "IBM delivers Power-based chip for Microsoft Xbox 360 worldwide launch". IBM. 2005-10-25. Archived from the original on 2007-03-11. Retrieved 2007-02-28.
{{cite web}}: Unknown parameter|deadurl=ignored (|url-status=suggested) (help) - DCC (1989-03-14). "Method and apparatus for causing an open circuit in a conductive line". Archived from the original on 2017-02-11.
{{cite web}}: Unknown parameter|deadurl=ignored (|url-status=suggested) (help) - Rizzolo, R. F.; Foote, T. G.; et al. (2007-02-13). "IBM System z9 eFUSE applications and methodology". doi:10.1147/rd.511.0065. Retrieved 2007-02-28.
- Speedy22 (2006-03-07). "XBOX 360 CPU Datasheet. Version 1.5" (PDF). Archived from the original (PDF) on 2006-03-15. Retrieved 2007-02-28.
{{cite web}}: Unknown parameter|deadurl=ignored (|url-status=suggested) (help)CS1 maint: numeric names: authors list (link) - Port, Otis (2005-06-06). "Mighty Morphing Power Processors". BusinessWeek.