SPI command censoring method and apparatus
US10133497B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 25, 2016 |
| Grant date | Nov 20, 2018 |
| Priority date | — |
| Expiry date | Jun 22, 2037 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2221/034
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method in a memory system having a security device and a serial external electrically erasable read-only memory (EEPROM) is disclosed. The method includes accepting N bits of a command prefix and matching the bits to command filtering rules. Upon matching the prefix to a command filtering rule, the method may perform a filter action associated with the matched rule. When the command prefix is for a destructive command prefix that can modify data in the EEPROM, the filter action may convert the command into a non-destructive command and inspect it for authentication. The converted command may be output to the external EEPROM without security processing in the security device and the external EEPROM may return read data without outputting. When the command prefix is for a non-destructive command prefix, the command may be allowed to pass through the external EEPROM unchanged without performing security processing in the security device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.