Programmable Logic Comparator Using LUT Stages for Relational Comparison
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional programmable logic devices face challenges in efficiently implementing relational comparison functions like 'greater than,' 'greater than or equal to,' 'less than,' or 'less than or equal to' without significant resource usage, as these functions are more difficult to implement using lookup tables compared to equality or inequality comparisons.
Innovation Solution
A method and device for implementing comparators in programmable logic devices by utilizing multiple stages with first and second comparison functions in lookup tables, where the output of one lookup table is used to select the result for each stage, and the lookup tables are implemented as shift registers to enable efficient loading and operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If relational comparison functions (greater than, less than, etc.) are implemented using conventional lookup tables in programmable logic devices, then the comparison functionality is achieved, but the configurable logic resources are significantly consumed
Solution Approach 1:
The comparator is divided into multiple stages, with each stage handling a portion of the comparison function. Each stage contains lookup tables that are selectively enabled based on the comparison type required, allowing the device to implement relational comparison functions while conserving configurable logic resources by activating only the necessary stages for each specific comparison operation.
2Adaptability or versatility
If multiple comparison functions are implemented in separate lookup tables, then the versatility of the comparator is improved, but the device complexity and resource usage increase
Solution Approach 1:
The comparator stages are designed to perform multiple comparison functions (equality, greater than, less than, greater than or equal to, less than or equal to) using the same hardware structure. By configuring the lookup tables in each stage according to the required comparison type, a single comparator implementation can handle all relational comparison operations without requiring separate dedicated circuits for each function.
Data Source
AI summary
A method of implementing a comparator in a device having programmable logic is described. The method comprises implementing a first comparison function in a first lookup table; implementing a second comparison function in a second lookup table; and using an output associated with the first comparison function to select an output of the comparator. A device having programmable logic comprising a comparator is also described.