An Effective Strategy of Area Reduction for Custom Instruction Based on Basic Cell

Abstract-Area reduction is very important for CI (Custom Instruction) on reconfigurable processor. However, for FPGA (Field Programmable Gate Array) structure, resource sharing method is inefficient for area reduction of data-path. In the paper, we propose an effective strategy of area reduction for custom instruction. Firstly, we partitioned data-path of the final CI to lots of BCs (Basic Cells). Then we checked all the validity of BCs to make sure that each BC can be realized using single logic element of FPGA, and selected the unique BC set to overlap original data-paths. Finally, on the basis of BC partitioning, we adopt an approach of Merging CIs to reduce area cost of data-path, which is different from traditional method of resource sharing. Experiment results show that basic cell can really represent FPGA architecture, compared to a method of efficient resource sharing, the approach of merging CIs based on BC can lead to more than 11 % average reduction of area. Keywords-custom instruction, FPGA, area reduction, merging I