Noise reduction system and method for reducing switching noise in an interface to a large width bus
US6763406B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 1, 2001 |
| Grant date | Jul 13, 2004 |
| Priority date | — |
| Expiry date | Jun 7, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F13/4068
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A method of communicating a data word via a bus includes driving the data word onto the bus in whichever one of a true polarity form and a complement polarity form that requires fewer bus lines to change state relative to a present state of each bus line, and providing an indicator signal to the bus to indicate which polarity form of the data word is driven onto the bus. The data word and the indicator signal may be received from the bus, and the polarity form of the data word is conditionally inverted in response to the indicator signal. A noise reduction system includes, for one embodiment, a sending circuit which compares each bit of a data word to be next communicated onto the bus against a corresponding bit of the present data word on the bus. If more than half the bits differ, then the next data word is inverted to form a complement next data word. The complement next data word is instead communicated onto the bus along with an indicator signal to indicate that a complement data word is communicated onto the bus. Consequently, no more than half the bits of the bus ever change state at a time, thus reducing the switching noise associated with communicating data words onto the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.