Back to results
US 6,888,373 B2Granted
Fracturable incomplete look up table for area efficient logic elements
AssigneeAltera Corporation
InventorsSinan Kaptanoglu, David Lewis, Bruce Pedersen
Life of this patent
Estimating the term…
Abstract
Disclosed is a configurable logic circuit that includes at least 6 inputs and at least two outputs. The configurable logic element can carry out only a subset of all 6-input logic functions and, thus, requires a substantially smaller silicon area than a 6-LUT that can perform all 6-input logic functions. Also, the configurable logic circuit can be configured such that a first subset of the inputs drive one of the outputs and a second subset of the inputs drive another output.
Claims30
A configurable logic circuit comprising:
- at least 6 inputs;
- at least a first output and a second output;
- no more than 25 memory bits which are programmable to completely configure the logic function performed by the configurable logic circuit;
- wherein the configurable logic circuit can be configured such that one of either
- the at least 6 inputs drive the first output to generate a 6 input logic function;
- and
- a first subset of the at least 6 inputs drives the first output and a second subset of the at least 6 inputs drives the second output;
- and
- wherein the configurable logic circuit is configurable to perform all possible 4 input logic functions.
6 more elements
A configurable logic circuit comprising:
- at least 6 inputs;
- at least a first output and a second output;
- a complete 4-LUT driven directly by at least 2 of the at least 6 inputs;
- at least one configuration in which one of either;
- the at least 6 inputs drive the first output to generate a 6 input logic function;
- and
- 6-n of the at least 6 inputs drive the first output to generate a 6-n input logic function and 6-m of the at least 6 inputs drive the second output to generate a 6-m input logic function, where m and n are each integers with m ranging from 3 to 5, inclusive, and n ranging from 1 to 5, inclusive;
- and
- wherein the configurable logic circuit can be configured to perform only a subset of all possible 6 input logic functions.
6 more elements
A configurable logic circuit comprising:
- at least 7 inputs;
- at least a first output and a second output;
- at least a third output configurable to be directly driven by a first one of the at least 7 inputs;
- no more than 32 memory bits which are programmable to completely configure the logic function performed by the configurable logic circuit;
- and
- wherein the configurable logic circuit can be configured such that one of either;
- 6 of the at least 7 inputs drive the first output to generate a 6 input logic function;
- and
- a first subset of the at least 7 inputs drives the first output and a second subset of the at least 7 inputs drives the second output.
6 more elements
Dependencies are inferred from the claim text.