Binary Logic Circuit for Constant Fraction Integer Multiplication

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Solution Overview

Problem

Existing integrated circuit designs for division operations, especially when the divisor is a constant, are inefficient due to complex logic implementations, consuming more area and resources compared to multiplication operations.

Innovation Solution

A binary logic circuit is designed to perform division as a multiply-add operation by optimizing the values of a, b, and k, where a and b are fixed integers, and k is the smallest integer that satisfies specific modular conditions, allowing the division operation to be expressed as ax+b2k, with the logic circuit optimized to minimize hardware complexity and area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If division operation is implemented using conventional logic circuits, then the division function is achieved, but the hardware area and complexity are excessive

Engineering Contradiction:
Improvehardware complexityVSAvoiddivision operation inefficiency
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent transforms the division operation parameters by expressing 1/q as a binary fraction and using the identity x/q = x*(2^k/q)*2^-k. This parameter transformation converts division into multiplication by a pre-computed constant (2^k/q), followed by a simple right shift, dramatically reducing hardware complexity while maintaining accuracy.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical division circuit with a multiplication circuit. By pre-computing the constant a = 2^k/q and storing it in a lookup table or register, the division operation x/q becomes a multiplication x*a followed by a right shift by k bits. This substitution leverages the fact that multiplication is more efficiently implemented in hardware than division.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Area of stationary object

If division is expressed as multiplication by constant fraction, then area is reduced, but finding optimal a, b, k values is complex

Engineering Contradiction:
Improveintegrated circuit areaVSAvoidoptimization complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent performs preliminary computation of the constant a = 2^k/q during the design phase. By pre-calculating this value and storing it in a lookup table or register, the complex optimization problem is solved once at design time, allowing simple multiplication and shift operations at runtime. This preliminary action eliminates the need for complex real-time optimization logic.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses an approximate value of 1/q by finding the smallest k such that 2^k/q has a manageable binary representation. This partial action approach accepts a small approximation error in exchange for dramatically reduced hardware complexity, using only multiplication and shift operations instead of full division logic.

Inventive Principle:
Principle #16Partial or excessive action

3Device complexity

If suboptimal expressions of division logic are used, then implementation is simpler, but hardware area consumption increases

Engineering Contradiction:
Improvelogic implementation simplicityVSAvoidintegrated circuit area
Core Design Contradiction:
Device complexityVSArea of stationary object

Solution Approach 1:

The patent creates a copy of the constant value a = 2^k/q and stores it in a lookup table or register. This pre-computed copy allows the division operation to be performed efficiently using multiplication by this stored constant, avoiding the need for complex division logic while minimizing hardware area. The copied constant value is reused across multiple operations.

Inventive Principle:
Principle #26Copying

Data Source

PatentUS10235136B2Constant fraction integer multiplication
Publication Date: 2019.03.19 IMAGINATION TECH LTD
  • US10235136B2 patent drawing
  • US10235136B2 patent drawing
  • US10235136B2 patent drawing

AI summary

A binary logic circuit is provided for determining a rounded value ofpxq,where p and q are coprime constant integers with p<q and q≠2i, i is any integer, and x is an integer variable between 0 and integer M where M≥2q, the binary logic circuit implementing in hardware the optimal solution of the multiply-add operationax+b2kwhere a, b and k are fixed integers.