Applying the Logarithmic Number System to Application-Specific Designs

When designing a microprocessor, the choice of a given arithmetic greatly impacts characteristics such as the implementation of the functional units, the required word size, and even the optimum algorithms that can be used. The diversity of products that incorporate a microprocessor makes the best choice application or system dependent. The Logarithmic Number System (LNS) allows very fast, power-saving implementations for certain arithmetic operations such as multiplication, division and squaring. Using this number representation can provide very important savings in area and power consumption, as well as higher speeds for a variety of algorithms. Previous research has been conducted in this area, but LNS has not yet been acknowledged as a viable alternative by the market. This is probably due to the fact that often results obtained with LNS are very similar to those obtained with floating point. But LNS lacks the extensive practical experience and well-established standard that exist for floating point. This dissertation proposes a methodology for successfully exploiting LNS in