Programmable driver delay
US7233170B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 25, 2005 |
| Grant date | Jun 19, 2007 |
| Priority date | — |
| Expiry date | Dec 13, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/0276
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Data busses are configured as N differential channels driven by a data signal and its complement through two off-chip drivers (OCDs). Each OCD is preceded by a programmable delay element and a two way MUX. The two data channels either transmit the data signals or a common clock signal as determined by a select signal from a skew controller. The differential signals are received in a differential receiver and a phase detector. The output of the phase detector in each differential channel is routed through an N×1 MUX. The N×1 MUX is controlled by the skew controller. The output of the N×1 MUX is fed back as a phase error feedback signal to the skew controller. Each differential data channel is sequentially selected and the programmable delays are adjusted until the phase error feedback signal from the selected phase detector reaches a predetermined minimum allowable value. Periodic adjustment may be implemented for calibration.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.