Browse Prior Art Database

Modulo-M Circuit

IP.com Disclosure Number: IPCOM000060052D
Original Publication Date: 1986-Feb-01
Included in the Prior Art Database: 2005-Mar-08

Publishing Venue

IBM

Related People

Authors:
Pasco, RC [+details]

Abstract

This invention relates to an apparatus for converting a binary number C into a modulo-M residue by examining the status of predetermined bit positions of number C. A minimum number of circuits is required since table lookup is utilized. Let (Image Omitted) where ci e {0,1} is the value of the ith bit of C. Equality establishes the congruence (Image Omitted) from this, precompute the residue terms ri = 2i(mod M) and let the corresponding binary values ci establish whether the ri is to be included into the modulo-M sum (Image Omitted) A simple circuit may be constructed which performs this operation in parallel, as illustrated in the figure for the case M = 3. It is reminiscent of the tally circuit and barrel shifter examples from Mead and Conway, Introduction to VLSI Systems Design, Addison-Wesley, 1980, pp.