FPGA中专用可重构乘法器的设计

提出了一种新的嵌入在FPGA中可重构的流水线乘法器设计.该设计采用了改进的波茨编码算法,可以实现18×18有符号乘法或17×17无符号乘法.还提出了一种新的电路优化方法来减少部分积的数目,并且提出了一种新的乘法器版图布局,以便适应tilebased FPGA芯片设计所加的约束.该乘法器可以配置成同步或异步模式,也町以配置成带流水线的模式以满足高频操作.该设计很容易扩展成不同的输入和输出位宽.同时提出了一种新的超前进位加法器电路来产生最后的结果.采用了传输门逻辑来实现整个乘法器.乘法器采用了中芯国际0.13μm CMOS工艺来实现,完成18×18的乘法操作需要4.1ns.全部使用2级的流水线时,时钟周期可以达到2.5ns.这比商用乘法器快29.1%,比其他乘法器快17.5%.与传统的基于查找表的乘法器相比,该乘法器的面积为传统乘法器面积的1/32.

Design of a Dedicated Reconfigurable Multiplier in an FPGA

We design a reconfigurable pipelined multiplier embedded in an FPGA. This design is based on the modified Booth algorithm and performs 18 × 18 signed or 17 × 17 unsigned multiplication. We propose a novel method for circuit optimization to reduce the number of partial products. A new layout floorplan design of the multiplier block is reported to comply with the constraints imposed by the tile-based FPGA chip design. The multiplier can be configured as synchronous or asynchronous. Its operation can also be configured as pipelined for high-frequency operation. This design can be easily extended for different input and output bit-widths. We employ a novel carry look-ahead adder circuit to generate the final product. The transmission-gate logic is used for the low-level circuits throughout the entire multiplier for fast logic operations. The design of the multiplier block is based on SMIC 0. 13μm CMOS technology using full-custom design methodology. The operation of the 18 × 18 multiplier takes 4. 1ns. The two-stage pipelined operation cycle is 2.5ns. This is 29. 1% faster than the commercial multiplier and is 17. 5% faster than the multipliers reported in other academic designs. Compared with the distributed LUT-based multiplier,it demonstrates an area efficiency ratio of 33∶1.