High speed bus with tree structure for selecting bus driver
US5936424A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 14, 1997 |
| Grant date | Aug 10, 1999 |
| Priority date | — |
| Expiry date | Oct 14, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K19/017581
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
According to the invention, a structure is provided for driving a bus line that is both fast and small. Instead of a plurality of tristate buffers, one for each input signal, a plurality of multiplexers or gates is connected into a tree structure. The tristate enable line of the tristate buffer becomes the control line for enabling the tree structure to place its own input signal onto the bus instead of propagating the signal already on the bus. A buffer element then allows the resulting signal to be tapped from the bus. One embodiment of the invention includes lookahead logic similar to a lookahead carry chain. This allows large numbers of input lines to be connected to a bus line while retaining high speed. The symmetrical delay of a tree structure minimizes the greatest delay and thus increases predicted speed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.