Flexible macrocell interconnect
US6927601B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 21, 2002 |
| Grant date | Aug 9, 2005 |
| Priority date | — |
| Expiry date | Dec 22, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K19/17736
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Methods and apparatus for novel routing structures and methods that improve fitting of user-defined functions onto programmable logic devices. In particular, second time fitting is improved. Exemplary structures and methods include allowing product terms to be expanded using inputs from more than one neighboring macrocell by providing multiple expansion and bypassing paths. Also, product term OR shifting prevents macrocell output stages from being buried and made inaccessible, and macrocell outputs are provided on expander word lines, increasing efficiency of those lines, as well as conserving routing resources. Expansion, bypassing, OR shifting, and expander word lines may terminate at logic array block boundaries or may continue beyond these boundaries to other logic array blocks.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.