RCA on FPGAs Designed by RTL Design Methodology and Wave-Pipelined Operation

Field-programmable gate arrays (FPGAs) are used in various systems that use reconfigurable function. Conventional FPGAs have been developed by a transistor-level description for minimizing routing delay. Although FPGAs developed by the register transfer level (RTL) design methodology provide various benefits to the designers of a system-on-achip (SoC), they have not been realized. Therefore, the authors have advanced their development. They should be shown to operate in a practical throughput. For this purpose, circuits on them need to be designed and evaluated. In this paper, a ripple-carry adder (RCA) is designed on them and the throughput of the RCA is evaluated. The throughput shows that it is applicable to network processors. In addition, a wave-pipelined operation without changing the RCA reveals that the problem of routing delay in the FPGAs developed by the RTL methodology is mitigated. The contributions of this paper are to clarify that a 4-bit adder can be implemented on the FPGAs and the throughput of it can be improved by wave-pipelined operations.