A FPGA IEEE-754-2008 decimal64 Floating-Point adder/subtractor

Abstract

This paper describes the FPGA implementation of a Decimal Floating Point (DFP) adder/subtractor. The design performs addition and subtraction on 64-bit operands that use the IEEE 754-2008 decimal encoding of DFP numbers and is based on a fully pipelined circuit. The design presents a novel hardware for pre-signal generation stage and an enhanced version of previously published leading zero stage. The design can operate at a frequency of 200 MHZ on a Virtex-5 with a latency of 8 cycles. The presented DFP adder/subtractor supports operations on the decimal64 format and it is easily extendable for the decimal128 format. To our knowledge, this is the first hardware FPGA design for adding and subtracting IEEE 754-2008 using decimal64 encoding.