Digital front end for time measurement and generation of electrical signals
US5047967A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 19, 1989 |
| Grant date | Sep 10, 1991 |
| Priority date | — |
| Expiry date | Jul 19, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/0673
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An integrated circuit cell module for performing precise time measurements for use in applications such as disk drive controllers. The combination of the cell module and a hard disk controller chip creates a complete hard disk controller in a single chip without the need for external analog components normally required for classic phase lock loop hard disk controllers. A problem in designing such a unified chip is that it must be digital in nature. Therefore, the maximum resolution with which signals generated by the disk drive (Rddata signals) can be measured and signals generated by the controller for writing to disk (Wrdata signals) can be generated is dependent on the clock which drives the controller chip. In hard disk controllers, the data rate is such that the minimum distance between adjacent Rddata or Wrdata pulses is approximately 100 ns which would require an oscillator having a speed which would be impractical in a design. This problem is solved using standard CMOS gates to measure the distance between a reference clock and the Rddata pulse to 2 ns. accuracy. This measurement is provided as a binary number to the hard disk controller which uses this information along wi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.