One-time programmable memories for key storage
US7818584B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 25, 2005 |
| Grant date | Oct 19, 2010 |
| Priority date | — |
| Expiry date | May 14, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/16
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Circuits, methods, and apparatus that store and prevent modification or erasure of stored encoding keys, serial identification numbers, or other information. An encoding key stored with an embodiment of the present invention may be used to decode a configuration bitstream on an integrated circuit, such as an FPGA. A serial number may be used to track or authenticate an integrated circuit. Embodiments of the present invention store this information in a memory such as an SRAM, DRAM, EPROM, EEPROM, flash, fuse array, or other type of memory. In order to prevent its erasure or modification, write enable circuitry for the memory is then permanently disabled, and if the memory is volatile, a continuous power supply is provided. Further refinements verify that the write enable circuitry has been disabled before allowing the device to be configured or to be operable.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.