Exploiting Resonant Behavior to Reduce Inductive Noise

• Published in: International Symposium on Computer Architecture: Proceedings of the 31st annual international symposium on Computer architecture : Munchen, Germany; 19-23 June 2004 p. 288
• Main Authors: Powell, Michael D., Vijaykumar, T. N.
• Format: Conference Proceeding
• Language: English
• Published: Washington, DC, USA IEEE Computer Society 02.03.2004
• Series: ACM Conferences
• Subjects: Applied sciences; Electronics; Exact sciences and technology; Hardware; Hardware > Hardware validation; Integrated circuits; Integrated circuits by function (including memories and processors); Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Electric generator; High performance; Noise reduction; Capacitive transducer; Power supply; Low power; Noise control; Decoupling; Electrical network; Response time; Resonance frequency; Computer architecture; Microprocessor; Reliability; High frequency; Capacitor; Logistics
• ISBN: 9780769521435; 0769521436
• ISSN: 1063-6897
• DOI: 10.5555/998680.1006726

Inductive noise in high-performance microprocessors is a reliabilityissue caused by variations in processor current (di/dt)which are converted to supply-voltage glitches by impedances inthe power-supply network. Inductive noise has been addressed byusing decoupling capacitors to maintain low impedance in thepower supply over a wide range of frequencies. However, evenwell-designed power supplies exhibit (a few) peaks of high impedanceat resonant frequencies caused by RLC resonant loops. Previousarchitectural proposals adjust current variations bycontrolling instruction fetch and issue, trading off performanceand energy for noise reduction. However, the proposals do notconsider some conceptual issues and have implementation challenges.The issues include requiring fast response, responding tovariations that do not threaten the noise margins, or respondingto variations only at the resonant frequency while the range ofhigh impedance extends to a resonance band around the resonantfrequency. While previous schemes reduce the magnitude of variations,our proposal, called resonance tuning, changes the frequencyof current variations away from the resonance band to anon-resonant frequency to be absorbed by the power supply.Because inductive noise is a resonance problem, resonance tuningreacts only to repeated variations in the resonance band, andnot to isolated variations. Reacting after a few repetitions allowsmore time for the response and reduces unnecessary responses,decreasing performance and energy loss.