Carry logic design having simplified timing modeling for a field programmable gate array
US6847228B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 19, 2002 |
| Grant date | Jan 25, 2005 |
| Priority date | — |
| Expiry date | Feb 25, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K19/1737
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A configurable logic block (CLB) slice is provided that includes a single path for a carry input signal to propagate through the CLB slice as a carry output signal. This single path includes a multiplexer that is configured to receive the input signals (including the carry input signal) and provides an output signal that can be routed as the carry output signal. A driver circuit can be coupled to the output terminal of the multiplexer, thereby improving the drive of the single path. A separate path is provided in parallel with the first multiplexer path, thereby enabling the carry input signal to be applied to exclusive OR gates within the CLB slice, or to be provided as an intermediate carry output signal. The single path provides a relatively fast and consistent manner of routing the carry input signal through the CLB slice as the carry output signal. The first and second paths accommodate a carry initialization signal as well as an intermediate carry input signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.