High frequency detection circuit and method
US6259279A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 28, 2000 |
| Grant date | Jul 10, 2001 |
| Priority date | — |
| Expiry date | Jan 28, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K5/26
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The present invention is a high frequency detection circuit (10) which includes a high frequency filter (12) and a frequency comparator (14) which compares the output of the high frequency filter with the incoming clock signal to determine if the high frequency filter is in operation. If operating, a status register is set which a microcontroller can poll to determine if an attack has been attempted. A microcode programmer can then control what sequence of events occur once the register has been set. Alternatively, detection of operation of the high frequency filter could automatically trigger a reset or interrupt of the microcontroller.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.