Enhanced macrocell module having expandable product term sharing capability for use in high density CPLD architectures
US6653860B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 10, 2001 |
| Grant date | Nov 25, 2003 |
| Priority date | — |
| Expiry date | Sep 30, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K19/177
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An improved, high density CPLD includes a plurality of macrocell sections. Each macrocell section can receive a relatively large number of independent input terms and can generate as a base cluster, at least as many as 5 different product term signals (PT's) therefrom. Part or all of the macrocell's local 5 PT's may be used for generating a local sum-of-products (SoP) signal in a local, first-level ORring operation. Additionally SoP's generated in neighboring macrocell sections may be selectively and incrementally cascaded (cross-laced) for supplemental summing into the local SoP signal. SoP signals of neighboring sections may be further selected in a sums sharing array for second level summing. The combination of the first-level cascading (cross-lacing) and second-level sums sharing provides a wide range of programmably selectable granulations including that of having relatively fast generation of a sum of just a few PT's (e.g., ≦5 PT's) to having slower generation of sums of a much larger number of PT's (e.g., ≦160 PT's).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.