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Fixed-Point Computer Arithmetic

  1. Earl E. Swartzlander Jr.

Published Online: 15 JAN 2008

DOI: 10.1002/9780470050118.ecse956

Wiley Encyclopedia of Computer Science and Engineering

Wiley Encyclopedia of Computer Science and Engineering

How to Cite

Swartzlander, E. E. 2008. Fixed-Point Computer Arithmetic. Wiley Encyclopedia of Computer Science and Engineering. .

Author Information

  1. University of Texas at Austin, Austin, Texas

Publication History

  1. Published Online: 15 JAN 2008

Abstract

The speed of a computer is determined to a first order by the speed of the arithmetic unit and the speed of the memory. Although the speed of both units depends directly on the implementation technology, arithmetic unit speed also depends strongly on the logic design. Even for an integer adder, speed can vary easily by an order of magnitude, whereas the complexity varies by less than 50%. Much arithmetic is performed with fixed-point numbers, which have constant scaling (i.e., the position of the binary point is fixed). The numbers can be interpreted as fractions, integers, or mixed numbers, which depends on the application. Pairs of fixed-point numbers are used to create floating-point numbers, the subject of another article.

Keywords:

  • algorithms;
  • arithmetic;
  • adder;
  • matrix;
  • number system;
  • newton-raphson