A hybrid radix-4 and approximate logarithmic multiplier for energy efficient image processing

Lotrič, Uroš (author), Pilipović, Ratko (author), Bulić, Patricio (author)

Multiplication is an essential image processing operation commonly implemented in hardware DSP cores. To improve DSP cores’ area, speed, or energy efficiency, we can approximate multiplication. We present an approximate multiplier that generates two partial products using hybrid radix-4 and logarithmic encoding of the input operands. It uses the exact radix-4 encoding to generate the partial product from the three most significant bits and the logarithmic approximation with mantissa trimming to approximate the partial product from the remaining least-significant bits. The proposed multiplier fills the gap between highly accurate approximate non-logarithmic multipliers with a complex design and less accurate approximate logarithmic multipliers with a more straightforward design. We evaluated the multiplier’s efficiency in terms of error, energy (power-delay-product) and area utilisation using NanGate 45 nm. The experimental results show that the proposed multiplier exhibits good area utilisation and energy consumption and behaves well in image processing applications.

• Language: English
• Keywords: approximate multiplier, approximate computing, arithmetic circuit design, hybrid encoding, radix-4 encoding, logarithmic encoding, energy-efficient processing
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FRI - Faculty of Computer and Information Science
• Publication status: Published
• Publication version: Version of Record
• Year: 2021
• Number of pages: 20 str.
• Numbering: Vol. 10, iss. 10, art. 1175
• PID: 20.500.12556/RUL-135536
• UDC: 004
• ISSN on article: 2079-9292
• DOI: 10.3390/electronics10101175
• COBISS.SI-ID: 63386371
• Publication date in RUL: 17.03.2022

Record is a part of a journal

• Title: Electronics
• Shortened title: Electronics
• Publisher: MDPI
• ISSN: 2079-9292
• COBISS.SI-ID: 523068953

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.
• Licensing start date: 14.05.2021

Secondary language

• Language: Slovenian
• Keywords: aproksimativni množilnik, aproksimativno računalništvo, načrtovanje aritmetičnih vezij, hibridno kodiranje, radix-4 kodiranje, logaritemsko kodiranje, energijsko učinkovito računanje