As we approach Gigascale Integration, chip power consumption is becoming a critical system parameter. Clock-gating idle units provides needed reductions in power consumption. However, it introduces inductive noise that can limit voltage scaling. This paper introduces an architectural approach for reducing inductive noise due to clock-gating through gradual activation/deactivation of units. This technique provides a 2x reduction in ground bounce on a 16 bit ALU simulated in SPICE, while reducing simulated SPEC95 performance by less than 5% on a typical superscalar architecture.

No abstract

A dynamic speculative multithreaded processor automatically extracts thread level parallelism from sequential binary applications without software support. The hardware is responsible for partitioning the program into threads and managing inter-thread dependencies. Current published dynamic thread partitioning algorithms work by detecting loops, procedures, or partitioning at fixed intervals. Research has thus far examined these algorithms in isolation from one another. This paper makes two contributions. First, it quantitatively compares different dynamic partitioning algorithms in the context of a fixed architecture. The architecture is a single-chip shared memory multiprocessor enhanced to allow thread and value speculation. Second, this paper presents a new dynamic partitioning algorithm called MEM-slicing. Insights into the development and operation of this algorithm are presented. The technique is particularly suited to irregular, non-numeric programs, and greatly outperforms other algorithms in this domain. MEMslicing is shown to be an important tool to enable the automatic parallelization of irregular binary applications. Over SPECint95, an average speedup of 3.4 is achieved on 8 processors.

In the modern era of wire-dominated

Switching activity-generated power-supply grid-noise presents a major obstacle to the reduction of supply voltage in future generation semiconductor technologies. A popular technique to counter this issue involves the usage of decoupling capacitors. This paper presents a novel design technique for sizing and placing on-chip decoupling capacitors based on activity signatures from the microarchitecture. Simulation of a typical processor workload (SPEC95) provides a realistic stimulation of microarchitecture elements that is coupled with a spatial power grid model. Evaluation of the proposed technique on typical microprocessor implementations (the Alpha 21264 and the Pentium II) indicates that this technique can produce up to a 30% improvement in maximum noise levels over a uniform decoupling capacitor placement strategy.