An Embedded Reconfigurable IP Core with Variable Grain Logic Cell Architecture

Reconfigurable logic devices (RLDs) are classified as the fine-grained or coarse-grained type based on their basic logic cell architecture. In general, each architecture has its own advantage. Therefore, it is difficult to achieve a balance between the operation speed and implementation area in various applications. In the present paper, we propose a variable grain logic cell (VGLC) architecture, which consists of a 4-bit ripple carry adder with configuration memory bits and develop a technology mapping tool. The key feature of the VGLC architecture is that the variable granularity is a tradeoff between coarse-grained and fine-grained types required for the implementation arithmetic and random logic, respectively. Finally, we evaluate the proposed logic cell using the newly developed technology mapping tool, which improveslogic depth by 31% and reduces the number of configuration data by 55% on average, as compared to the Virtex-4 logic cell architecture.