A 10 ns hybrid number system data execution unit for digital signal processing systems

A high-performance data execution unit suitable for computation-intensive digital signal processing systems is described. This unit uses the hybrid number system approach to speed up the basic arithmetic operations while remaining compatible with a standard IEEE 32-b floating-point format. However, all the arithmetic operations are performed in the 32 b logarithmic number system (LNS) domain. This chip is designed using a 3.4 V 0.8 μm CMOS technology with double-layer metallization. Conversion algorithms, chip architecture, design methodology, and major circuit components are discussed. A macrocell design methodology is adopted in order to achieve high-performance custom design circuits with the convenience of an automatic layout system. Computer simulations indicate that all the 32 b floating-point arithmetic operations (multiplication, division, squaring, and square root) can be executed in 10 ns. Extension of this unit into a 64 b double-precision floating-point system and multiply-accumulation applications are also presented