Accession Number : ADD013562

Title :   Arithmetic Pipeline for Image Processing.

Descriptive Note : Patent, Filed 6 Jun 85, patented 13 Oct 87,

Corporate Author : DEPARTMENT OF THE AIR FORCE WASHINGTON DC

Personal Author(s) : Steiner, Walter R

Report Date : 13 Oct 1987

Pagination or Media Count : 32

Abstract : The arithmetic pipeline processor (which is used for computer graphics such as a flight simulator) is a group of boards capable of solving an equation of the form A(m)B(n)+C(o)D(p)+E(q)F(r)+G(s)H(t) where A, B, C, D, E, F, G, H are 32-bit implied one floating point numbers, and m, n, o, p, q, r, s, t, can take on the values 1/4 1/2 1, 2 and 0. It includes a digital logarithmic calculator using shifters and stored tables to perform arithmetic functions such as multiplication, division, squares roots, and fourth roots. It comprises two input ports each capable of receiving digital data N bits wide. Included are a log transform unit, a log sum or difference unit and an antilog unit. Following these is an M-bit Arithmetic Logic Unit (ALU) and circuitry for converting between fixed point and floating point numbers. It uses piece wise linear approximation in conjunction with stored slope information in tables to do the transform calculation of logarithms and antilogarithms. The M-bit arithmetic unit performs accumulation of up to K terms. In a specific embodiment, N=32, M=36, and K=128. Note that a pipeline processor has no central processing unit or software in itself, but it may interface with a computer for inputs and outputs including control information.

Descriptors :   *ARITHMETIC, *CENTRAL PROCESSING UNITS, *COMPUTER GRAPHICS, *COMPUTER PROGRAMS, *CONTROL, *DIGITAL SYSTEMS, *FLOATING POINT OPERATION, *IMAGE PROCESSING, *PROCESSING EQUIPMENT, *PATENTS, APPROXIMATION(MATHEMATICS), ARITHMETIC UNITS, CALCULATORS, DATA BASES, EQUATIONS, FINITE DIFFERENCE THEORY, FLIGHT SIMULATORS, FUNCTIONS(MATHEMATICS), LINEAR SYSTEMS, LOGARITHM FUNCTIONS, LOGIC DEVICES, PIPELINES, SLOPE, TABLES(DATA)

Subject Categories : Computer Hardware
      Computer Programming and Software

Distribution Statement : APPROVED FOR PUBLIC RELEASE