9 research outputs found
ํด๋ญ ๊ฒ์ดํ ๋ฐ ํ๋ฆฝ ํ๋กญ ๋์ ์ต์ ํ๋ฅผ ์ํ ์ค๊ณ ๋ฐ ์๊ณ ๋ฆฌ์ฆ
ํ์๋
ผ๋ฌธ (์์ฌ)-- ์์ธ๋ํ๊ต ๋ํ์ : ๊ณต๊ณผ๋ํ ์ ๊ธฐยท์ ๋ณด๊ณตํ๋ถ, 2019. 2. ๊นํํ.๋ณธ ๋
ผ๋ฌธ์์๋ ํ์ค ์
์์๋ถํฐ ๋ฐฐ์น ๋จ๊ณ์ ์ด๋ฅด๋ ๋ค์ํ ์ค๊ณ๋จ์์์ ์นฉ์
๋์ ์ ๋ ฅ์ ์ต์ ํ ๊ธฐ๋ฒ์ ์๊ฐํ๋ค. ์ด ์ฐ๊ตฌ๋ ์ฐ์ ๋ฐ์ดํฐ ๊ตฌ๋ํ (์ฆ, ํ ๊ธ๋ง
๊ธฐ๋ฐ) ํด๋ญ ๊ฒ์ดํ
์ด ์ข
๋ ํด๋ญ ๊ฒ์ดํ
๊ธฐ๋ฒ๋ค์์ ๊ฒฐ์ฝ ๋ค๋ฃจ์ด์ง์ง ์์๋ ํ๋ฆฝ ํ
๋กญ์ ํฉ์ฑ๊ณผ ๋ฐ์ ํ๊ฒ ํตํฉ๋ ์ ์๋ ๋ฐฉ๋ฒ์ ์ฐ๊ตฌํ๋ค. ์ฐ๋ฆฌ์ ๊ด์ธก์ ํต์ฌ์ ํ๋ฆฝ
ํ๋กญ ์
์ ์ผ๋ถ ๋ด๋ถ ๋ถํ์ด ํด๋ญ ๊ฒ์ดํ
์ธ์์ด๋ธ ์ ํธ๋ฅผ ์์ฑ ํ๊ธฐ ์ํด ์ฌ์ฌ์ฉ
๋ ์ ์๋ค๋ ๊ฒ์ด๋ค. ์ด๋ฅผ ๋ฐํ์ผ๋ก eXOR-FF ๋ผ๊ณ ๋ถ๋ฆฌ๋ ์๋กญ๊ฒ ์ต์ ํ๋ ํ๋ฆฝ
ํ๋กญ ๋ฐฐ์ ๊ตฌ์กฐ๋ฅผ ์ ์ํฉ๋๋ค. ์ด ๊ตฌ์กฐ์์๋ ๋งค ํด๋ญ ์ฃผ๊ธฐ๋ง๋ค ๋ด๋ถ ๋ก์ง์ ์ฌ์ฌ์ฉ
ํ์ฌ ํด๋ญ ๊ฒ์ดํ
์ ํตํด ํ๋ฆฝ ํ๋กญ์ ํ์ฑํํ ์ง ๋๋ ๋นํ์ฑํํ ์ง ๊ฒฐ์ ํฉ๋๋ค.
๋ชจ๋ ์์ ํ๋ฆฝ ํ๋กญ ๋ฐ ํ ๊ธ๋ฆด ๊ฐ์ง ๋ก์ง์์์ ์์ญ์ ์ ์ฝํจ์ ๋ฐ๋ผ์ ๋์ค ๋ฐ
๋์ ์ ๋ ฅ์ ์ ์ ํจ๊ณผ๋ฅผ ๋ฌ์ฑํฉ๋๋ค. ๊ทธ๋ฐ ๋ค์, ๋ ๊ฐ์ง๊ณ ์ ํ ์ฅ์ ์ ์ ๊ณตํ๋
๋ฐฐ์น/ํ์ด๋ฐ ์ธ์ ํด๋ญ ๊ฒ์ดํ
ํ์์ ๋ํ ํฌ๊ด์ ์ธ ๋ฐฉ๋ฒ๋ก ์ ์ ์ํฉ๋๋ค. ํด๋น ๋ฐฉ
๋ฒ๋ก ์ eXOR-FF ์ ์ด์ ์ ๊ทน๋ํํ๊ณ , ์ ๋ ฅ ์๋น ๋ฐ ํ์ด๋ฐ ์ํฅ์ ๋ถํด์ ๋ํ
์ ๋ฐ ๋ถ์์ ์ํํ๊ณ ํ๋ญ ๊ฒ์ดํ
์ฐธ์์ ํต์ฌ ์์ง์ ๋น์ฉ๊ธฐ๋ฅ์ผ๋ก ๋ณํํ๋๋ฐ
๊ฐ์ฅ ์ ํฉํฉ๋๋ค. ISCAS89, ITC89, ITC99 ๋ฐ IWLS 2005์ ๋ฒค์น ๋งํฌ ํ๋ก๋ฅผ ์ฌ์ฉ
ํ ์คํ์ ํตํด ์ ์ ๋ ๋ฐฉ๋ฒ์ด ์ด์ ์ ๋ฐ์ดํฐ ๊ตฌ๋ ํด๋ก ๊ฒ์ดํ
๋ฐฉ์๊ณผ ๋น๊ตํ์ฌ ์ด
์ ๋ ฅ์ 5.6 % ๋ฐ ๋ฉด์ ์ผ๋ก 5.3 % ์ค์ผ ์ ์์์ ๋ณด์ฌ ์ฃผ์๋ค.In this paper, we introduce dynamic power optimization techniques applicable for
various design stage from standard cell to placement stage. This work firstly investi๏ฟฝgates the problem of how designing data-driven (i.e., toggling based) clock gating can
be closely integrated with the synthesis of flip-flops, which has never been addressed
in the prior clock gating works. Our key observation is that some internal part of a
flip-flop cell can be reused to generate its clock gating enable signal. Based on this,
we propose a newly optimized flip-flop wiring structure, called eXOR-FF, in which
an internal logic can be reused for every clock cycle to decide if the flip-flop is to
be activated or inactivated through clock gating, thereby achieving area saving (thus,
leakage as well as dynamic power saving) on every pair of flip-flop and its toggling
detection logic. Then, we propose a comprehensive methodology of placement/timing๏ฟฝaware clock gating exploration that provides two unique strengths: best suited for max๏ฟฝimally exploiting the benefit of eXOR-FFs and precise analyses on the decomposition
of power consumptions and timing impact, and translating them into cost functions in
core engine of clock gating exploration.
Through experiments with benchmark circuits in ISCAS89, ITC89, ITC99 and
IWLS 2005, it is shown that our proposed method is able to reduce the total power by
5.6% and total cell area by 5.3% compared with the previous data-driven clock gating
method in [1].Abstract
Contents
List of Tables
List of Figures
1 Introduction
1.1 Power Consumption in CMOS Digital Design
1.2 Low Power Design Methodologies
1.3 Contribution of This Thesis
2 Preliminary and Motivations 6
2.1 Background
2.2 Observation on Area and Power Saving
2.3 Observation on Timing Impact
3 Redesign of Flip-flops Specialized for Clock Gating
3.1 Observation on Area Impact
4 Placement-aware Clock Gating Methodology Utilizing eXOR-FF Cells
4.1 Overall Design Flow
4.2 Cost Formulation for Conventional Clock Gating
4.3 Cost Formulation for Our Clock Gating using eXOR-FFs
5 Experiments
5.1 Experimental Setup
5.2 Experimental Results
5.3 Comparing with Industry Algorithm
6 Conclusion
Abstract (In Korean)Maste