Chris Wilkerson

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One of the most effective techniques to reduce a processor’s power consumption is to reduce supply voltage. However, reducing voltage in the context of manufacturing-induced parameter variations cancause many types of memory circuits to fail. As a result, voltage scaling is limited by a minimum voltage, often called Vccmin, beyond which circuits may(More)
A 65 nm resilient circuit test-chip is implemented with timing-error detection and recovery circuits to eliminate the clock frequency guardband from dynamic supply voltage and temperature variations as well as to exploit path-activation probabilities for maximizing throughput. Two error-detection sequential (EDS) circuits are introduced to preserve the(More)
Voltage scaling is one of the most effective mechanisms to reduce microprocessor power consumption. However, the increased severity of manufacturing-induced parameter variations at lower voltages limits voltage scaling to a minimum voltage, Vccmin, below which a processor cannot operate reliably. Memory cell failures in large memory structures (e.g.,(More)
Today’s high performance processors tolerate long latency operations by means of out-of-order execution. However, as latencies increase, the size of the instruction window must increase even faster if we are to continue to tolerate these latencies. We have already reached the point where the size of an instruction window that can handle these latencies is(More)
Memory isolation is a key property of a reliable and secure computing system--an access to one memory address should not have unintended side effects on data stored in other addresses. However, as DRAM process technology scales down to smaller dimensions, it becomes more difficult to prevent DRAM cells from electrically interacting with each other. In this(More)
Voltage scaling is one of the most effective mechanisms to improve microprocessors' energy efficiency. However, processors cannot operate reliably below a minimum voltage, Vccmin, since hardware structures may fail. Cell failures in large memory arrays (e.g., caches) typically determine Vccmin for the whole processor. We observe that most cache lines(More)
Technology advancements have enabled the integration of large on-die embedded DRAM (eDRAM) caches. eDRAM is significantly denser than traditional SRAMs, but must be periodically refreshed to retain data. Like SRAM, eDRAM is susceptible to device variations, which play a role in determining refresh time for eDRAM cells. Refresh power potentially represents a(More)
A 45 nm microprocessor core integrates resilient error-detection and recovery circuits to mitigate the clock frequency guardbands for dynamic parameter variations to improve throughput and energy efficiency. The core supports two distinct error-detection designs, allowing a direct comparison of the relative trade-offs. The first design embeds(More)
Three circuit techniques for dynamic variation tolerance are presented: (i) Sensors with adaptive voltage and frequency circuits, (ii) Tunable replica circuits for timing-error prediction with error recovery, and (iii) Embedded error-detection sequential circuits with error recovery. These circuits mitigate the clock frequency guardbands for dynamic(More)