Method of measurement and compensation of an inaccurate clock signal
US5915108A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 1997 |
| Grant date | Jun 22, 1999 |
| Priority date | — |
| Expiry date | Jun 30, 2017 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02P7/0775
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for determining the actual frequency of an inaccurate clock signal then using the actual frequency to generate a compensation factor to correct calculations using the clock signal. The method includes counting the number of clock pulses in the clock signal over a predetermined and programmable period of time, and based on the clock pulse count, determining the actual frequency of the clock signal. Once the actual frequency of the clock signal is determined, this value is used to generate the compensation factor based on the expected or rated frequency of the clock signal to compensate for the calculations using the clock signal. The method has a particular application for use in a powertrain control module incorporating a low frequency resonator and a high frequency system clock, where the resonator generates an inaccurate clock signal which is highly stable for short periods of time and the system clock is relatively stable over long term but suffers from short term jitter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.