Interconnect Driver Design for Long Wires in Field-Programmable Gate Arrays

Designers of field-programmable gate arrays (FPGAs) are always striving to improve the performance of their designs. As they migrate to newer process technologies in search of higher speeds, the challenge of interconnect delay grows larger. For an FPGA, this challenge is crucial since most FPGA implementations use many long wires. A common technique used to reduce interconnect delay is repeater insertion. Recent work has shown that FPGA interconnect delay can be improved by using unidirectional wires with a single driver at only one end of a wire. With this change, it is now possible to consider interconnect optimization techniques such as repeater insertion. In this work, a technique to construct switch driver circuit designs is developed. Using this method, it is possible to determine the driver sizing, spacing and the number of stages of the circuit design. A computer-aided design model of the new circuit designs is developed to assess the impact they have on the delay performance of FPGAs. Results indicate that, by using the presented circuit design technique, the critical path can be reduced by 19 % for short wires, and up to 40 % for longer wires