가산기와 MIPS CPU 사례를 이용한 현대 FPGA의 특성연구

다국어 초록 (Multilingual Abstract)

The FPGA-based emulation is an essential step in ASIC design for validation. For emulation with maximal frequency, it is crucial to understand the FPGA characteristics. This paper attempts to analyze the performance characteristics of the modern FPGAs from renowned vendors, Xilinx and Altera, with a case study utilizing various adders and MIPS CPU. Unlike the common wisdom, ripple-carry adder (RCA) does not utilize the inherent carry-chain inside FPGAs when structurally designed based on 1-bit adders. Thus, the RCA shows the inferior performance to the other types of adders in FPGAs. Our study also reveals that FPGAs from Xilinx exhibit different characteristics from the ones from Altera. That is, the prefix adder, which is optimized for speed in ASIC design, shows the poor performance on Xilinx devices, whereas it provides a comparable speed to the IP core on Altera devices. It suggests that error-prone manual change of the original design can be avoided on Altera devices if area is permitted. Experiments with MIPS CPU confirm the arguments.