Apparatus and method for setting adequate drive strength based upon DC trace resistance
US7548433B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 12, 2005 |
| Grant date | Jun 16, 2009 |
| Priority date | — |
| Expiry date | Jul 19, 2027 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49004
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An information handing system having apparatus for setting adequate drive strength based upon direct current (DC) trace resistance uses a resistance detection traces for each signal layer of a printed circuit board. These resistance detection traces are coupled to pull-up resistors and routed with a length and cross-sectional geometry that is substantially equal to the worst case routing of a net on a bus that is to be free of receiver mask violations (inadequate received signal strengths). Reference voltage levels may be determined for each bus so as to be representative of the minimum voltage acceptable to guarantee that the worst-case DC trace resistance will not cause the bus waveforms to fail signal integrity. A voltage comparator circuit may be used to compare the determined reference voltage levels with the voltage levels of the resistance detection traces of each of the printed circuit board layers. When the voltage comparator determines that a resistance detection trace voltage is too low, an output from the voltage comparator may be used to generate an error message to a general purpose input-output (GPIO) that may initiate programming (e.g., change the flash memory) of a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.