Real time clock
US7702943B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 8, 2008 |
| Grant date | Apr 20, 2010 |
| Priority date | — |
| Expiry date | Jun 18, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F21/725
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A real time clock comprises a counter which stores a count value, the count value representing a time signal. The counter may be written, for example by a host processor (not shown), such that the time signal can be set to any desired value. The real time clock comprises a check register that stores a check value. The content of the check register (i.e. the check value) is modified each time a write operation is performed on the counter. For example, the content of the check register can be updated by a control signal each time a write operation is performed on the counter. The check value stored in the check register is used for determining whether a write operation performed on the counter is an authorized write operation or an unauthorized write operation. The check value may be incremented each time a write operation is performed, replaced with a new random number each time a write operation is performed, or a combination of both.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.