Hybrid Floating-Point Format for DSP Silicon Area Reduction

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Solution Overview

Problem

Existing digital signal processors and hardware accelerators face inefficiencies in numerical processing due to the complexity of conventional floating-point representations, leading to increased silicon area requirements and power consumption, particularly in wireless communication systems that demand high dynamic range and rapid execution of operations.

Innovation Solution

A hybrid floating-point format is introduced, representing numbers as a sign bit, exponent bits with bias, and mantissa bits, with special handling for zero and overflow conditions, allowing for a variable length format that simplifies exception handling and reduces power consumption while maintaining performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional floating-point representation is used, then numerical processing capability is provided, but silicon area increases and power consumption rises

Engineering Contradiction:
Improvenumerical processing capabilityVSAvoidsilicon area
Core Design Contradiction:
ProductivityVSArea of stationary object

Solution Approach 1:

The patent extracts and removes unnecessary complexity from conventional floating-point representation by eliminating support for special values (NaN, infinity, denormalized numbers) and using a simplified exponent format without bias encoding. This extraction of essential functionality reduces the silicon area required for implementation while maintaining core numerical processing capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes key parameters of the floating-point format: using unsigned integers instead of biased integers for exponents, allocating more bits to the mantissa (23 bits vs. conventional 23 bits but with different interpretation), and removing special value encodings. These parameter changes optimize the format for specific DSP applications, reducing hardware complexity and silicon area while maintaining numerical processing effectiveness.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If conventional floating-point representation is used, then numerical operations can be performed, but power consumption increases

Engineering Contradiction:
Improvenumerical operationsVSAvoidpower consumption
Core Design Contradiction:
ProductivityVSUse of energy by stationary object

Solution Approach 1:

The patent removes complex exception handling logic for special floating-point values (NaN, infinity, denormalized numbers) that present in conventional formats. This extraction eliminates unnecessary computational paths and control logic that would consume power, while retaining full capability for standard numerical operations required in DSP applications.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

By changing the exponent representation to unsigned integers and adjusting the mantissa interpretation, the patent simplifies the arithmetic operations required. This parameter change reduces the complexity of comparison, addition, and multiplication operations, thereby lowering power consumption while maintaining numerical operation capability.

Inventive Principle:
Principle #35Parameter changes

3Area of stationary object

If simplified floating-point format is used, then silicon area is reduced, but handling of special values becomes limited

Engineering Contradiction:
Improvesilicon areaVSAvoidhandling of special values
Core Design Contradiction:
Area of stationary objectVSAdaptability or versatility

Solution Approach 1:

The patent adopts a pragmatic approach by designing a floating-point format optimized for typical DSP workloads where special values (NaN, infinity, denormalized numbers) are rarely needed. The simplified format sacrifices support for these edge cases to achieve significant reductions in silicon area and complexity, accepting that the lost versatility has minimal impact on actual DSP performance and energy efficiency.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Data Source

PatentUS10324688B2System and method for a floating-point format for digital signal processors
Publication Date: 2019.06.18 FUTUREWEI TECHNOLOGIES INC
  • US10324688B2 patent drawing
  • US10324688B2 patent drawing
  • US10324688B2 patent drawing

AI summary

An embodiment of a system and method for performing a numerical operation on input data in a hybrid floating-point format includes representing input data as a sign bit, exponent bits, and mantissa bits. The exponent bits are represented as an unsigned integer including an exponent bias, and a signed numerical value of zero is represented as a first reserved combination of the mantissa bits and the exponent bits. Each of all other combinations of the mantissa bits and the exponent bits represents a real finite non-zero number. The mantissa bits are operated on with a “one” bit before a radix point for the all other combinations of the mantissa bits and the exponent bits.