The widespread use of microprocessor chips in high performance applications like
graphics simulators and low power applications like mobile phones, laptops,
medical applications etc. has made power estimation an important step in the
manufacture of VLSI chips. It has become necessary to estimate the power
consumption not only after the circuits have been laid out, but also during the
design of the modules of the microprocessor at higher levels of design
abstraction.
The design of a microprocessor is complex and is performed at multiple layers of
abstraction before it finally gets manufactured. The processor is first
conceptually designed using blocks at the system level, and then modeled using a
high-level language (C, C++, SystemC). This enables the early development of
software applications using these high-level models. The C/C++ model is then
translated to a hardware description language (HDL), that typically corresponds
to the register transfer level (RT-Level). Once the processor is defined at the
RT-Level, it is synthesized into gates and state elements based on user-defined
constraints. In this thesis, novel techniques to estimate the power consumed by
the microprocessor circuits at the gate level and RT-level of abstraction are
presented.
At the gate level, the average power consumed by microprocessor circuits is
straight-forward to estimate, as the implementation is known. However,
estimating the maximum or peak instantaneous power consumed by the
microprocessor as a whole, when it is executing instructions, is a hard problem
due to the high complexity of the state space involved. An hierarchical approach
to estimate the peak power using powerful search techniques and formal tools is
presented in this thesis. This approach has been extended and applied to solve
the problem of estimating the maximum supply drop. Details on this extension and
a discussion of promising results are also presented. In addition, this approach
has been applied to explore the possibility of minimizing the leakage component
of power dissipation, when the processor is idle.
At the register transfer level, estimating the average power consumed by the
circuits of the microprocessor is by itself a challenging problem. This is due
to the fact that their implementation is unknown at this level of abstraction.
The average power consumption directly depends on the implementation. The
implementation, in turn, depends on the performance constraint imposed on the
microprocessor. One of the factors affecting the performance of the
microprocessor, is the speed of operation of its circuits. Considering these
factors and dependencies (for making early design decisions at the RT-Level), a
methodology that estimates the power vs. delay curves of microprocessor circuits
has been developed. This will enable designers to make design decisions for even
rudimentary designs without going through the time consuming process of
synthesis. / text
| Identifer | oai:union.ndltd.org:UTEXAS/oai:repositories.lib.utexas.edu:2152/ETD-UT-2010-08-1907 |
| Date | 13 December 2010 |
| Creators | Sambamurthy, Sriram |
| Source Sets | University of Texas |
| Language | English |
| Detected Language | English |
| Type | thesis |
| Format | application/pdf |
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