Real time clock with integrated anti-rollback protection
US11636199B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 12, 2021 |
| Grant date | Apr 25, 2023 |
| Priority date | — |
| Expiry date | Aug 3, 2041 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F21/78
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A Real-Time Clock (RTC) block configured to output a current time as part of an ASIC configuration that guarantees that the RTC can never be rolled back beyond a checkpointed date and time. A checkpoint memory block is coupled to the RTC block and configured to include a stored active date/time checkpoint, and a set RTC logic block is coupled to the checkpoint memory block and to the RTC block and configured to permit setting the RTC block to an asserted new time request only when the asserted new time is in the future relative to the stored active date/time checkpoint. The active date/time checkpoint is stored in a non-volatile, single-write memory location such as in a one-time programmable (OTP) memory or in a bank of fuses so that the stored active date/time checkpoint is maintained whether or not power is interrupted to the checkpoint memory block.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.