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Optimizations of Cisco’s Embedded Logic Analyzer ModuleYang, Fangjin January 2009 (has links)
Cisco’s embedded logic analyzer module (ELAM) is a debugging device used for many of Cisco’s application specific integrated chips (ASICs). The ELAM is used to capture data of interest to the user and stored for analysis purposes. The user enters a trigger expression containing data fields of interest in the form of a logical equation. The data fields associated with the trigger expression are stored in a set of Match and Mask (MM) registers. Incoming data packets are matched against these registers, and if the user-specified data pattern is detected, the ELAM triggers and begins a countdown sequence to stop data capture. The current ELAM implementation is restricted in the form of trigger expressions that are allowed and in the allocation of resources. Currently, data fields in the trigger expression can only be logically ANDed together, Match and Mask registers are inefficiently utilized, and a static state machine exists in the ELAM trigger logic. To optimize the usage of the ELAM, a trigger expression is first treated as a Boolean expression so that minimization algorithms can be run. Next, the data stored in the Match and Mask registers is analyzed for redundancies. Finally, a dynamic state machine is programmed with a distinct set of states generated from the trigger expression. This set of states is further minimized. A feasibility study is done to analyze the validity of the results.
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Optimizations of Cisco’s Embedded Logic Analyzer ModuleYang, Fangjin January 2009 (has links)
Cisco’s embedded logic analyzer module (ELAM) is a debugging device used for many of Cisco’s application specific integrated chips (ASICs). The ELAM is used to capture data of interest to the user and stored for analysis purposes. The user enters a trigger expression containing data fields of interest in the form of a logical equation. The data fields associated with the trigger expression are stored in a set of Match and Mask (MM) registers. Incoming data packets are matched against these registers, and if the user-specified data pattern is detected, the ELAM triggers and begins a countdown sequence to stop data capture. The current ELAM implementation is restricted in the form of trigger expressions that are allowed and in the allocation of resources. Currently, data fields in the trigger expression can only be logically ANDed together, Match and Mask registers are inefficiently utilized, and a static state machine exists in the ELAM trigger logic. To optimize the usage of the ELAM, a trigger expression is first treated as a Boolean expression so that minimization algorithms can be run. Next, the data stored in the Match and Mask registers is analyzed for redundancies. Finally, a dynamic state machine is programmed with a distinct set of states generated from the trigger expression. This set of states is further minimized. A feasibility study is done to analyze the validity of the results.
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Real time Spaun on SpiNNaker : functional brain simulation on a massively-parallel computer architectureMundy, Andrew January 2017 (has links)
Model building is a fundamental scientific tool. Increasingly there is interest in building neurally-implemented models of cognitive processes with the intention of modelling brains. However, simulation of such models can be prohibitively expensive in both the time and energy required. For example, Spaun - "the world's first functional brain model", comprising 2.5 million neurons - required 2.5 hours of computation for every second of simulation on a large compute cluster. SpiNNaker is a massively parallel, low power architecture specifically designed for the simulation of large neural models in biological real time. Ideally, SpiNNaker could be used to facilitate rapid simulation of models such as Spaun. However the Neural Engineering Framework (NEF), with which Spaun is built, maps poorly to the architecture - to the extent that models such as Spaun would consume vast portions of SpiNNaker machines and still not run as fast as biology. This thesis investigates whether real time simulation of Spaun on SpiNNaker is at all possible. Three techniques which facilitate such a simulation are presented. The first reduces the memory, compute and network loads consumed by the NEF. Consequently, it is demonstrated that only a twentieth of the cores are required to simulate a core component of the Spaun network than would otherwise have been needed. The second technique uses a small number of additional cores to significantly reduce the network traffic required to simulated this core component. As a result simulation in real time is shown to be feasible. The final technique is a novel logic minimisation algorithm which reduces the size of the routing tables which are used to direct information around the SpiNNaker machine. This last technique is necessary to allow the routing of models of the scale and complexity of Spaun. Together these provide the ability to simulate the Spaun model in biological real time - representing a speed-up of 9000 times over previously reported results - with room for much larger models on full-scale SpiNNaker machines.
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Computations in Prime Fields using Gaussian IntegersEngström, Adam January 2006 (has links)
<p>In this thesis it is investigated if representing a field <i>Z</i><i>p</i><i>, p</i> = 1 (mod 4) prime, by another field <i>Z[i]</i>/ < <i>a + bi </i>> over the gaussian integers, with <i>p</i> = <i>a</i><i>2</i><i> + b</i><i>2</i>, results in arithmetic architectures using a smaller number of logic gates. Only bit parallell architectures are considered and the programs Espresso and SIS are used for boolean minimization of the architectures. When counting gates only NAND, NOR and inverters are used.</p><p>Two arithmetic operations are investigated, addition and multiplication. For addition the architecture over<i> Z[i]/ < a+bi ></i> uses a significantly greater number of gates compared with an architecture over<i> Z</i><i>p</i>. For multiplication the architecture using gaussian integers uses a few less gates than the architecture over <i>Z</i><i>p</i> for <i>p</i> = 5 and for<i> p</i> = 17 and only a few more gates when <i>p</i> = 13. Only the values 5, 13, 17 have been compared for multiplication. For addition 12 values, ranging from 5 to 525313, have been compared.</p><p>It is also shown that using a blif model as input architecture to SIS yields much better performance, compared to a truth table architecture, when minimizing.</p>
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Computations in Prime Fields using Gaussian IntegersEngström, Adam January 2006 (has links)
In this thesis it is investigated if representing a field Zp, p = 1 (mod 4) prime, by another field Z[i]/ < a + bi > over the gaussian integers, with p = a2 + b2, results in arithmetic architectures using a smaller number of logic gates. Only bit parallell architectures are considered and the programs Espresso and SIS are used for boolean minimization of the architectures. When counting gates only NAND, NOR and inverters are used. Two arithmetic operations are investigated, addition and multiplication. For addition the architecture over Z[i]/ < a+bi > uses a significantly greater number of gates compared with an architecture over Zp. For multiplication the architecture using gaussian integers uses a few less gates than the architecture over Zp for p = 5 and for p = 17 and only a few more gates when p = 13. Only the values 5, 13, 17 have been compared for multiplication. For addition 12 values, ranging from 5 to 525313, have been compared. It is also shown that using a blif model as input architecture to SIS yields much better performance, compared to a truth table architecture, when minimizing.
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IP Routing Table Compression Using TCAM and Distance-one MergeBollapalli, Kalyana Chakravarthy 2009 December 1900 (has links)
In an attempt to slow the exhaustion of the Internet Protocol (IP) address space,
Class-less Inter-Domain Routing (CIDR) was proposed and adopted. However, the
decision to utilize CIDR also increases the size of the routing table, since it allows
an arbitrary partitioning of the routing space. We propose a scheme to reduce the
size of routing table in the CIDR context. Our approach utilizes a well-known and
highly efficient heuristic to perform 2-level logic minimization in order to compress
the routing table. By considering the IP routing table as a set of completely specified
logic functions, we demonstrate that our technique can achieve about 25% reduction
in the size of IP routing tables, while ensuring that our approach can handle routing
table updates in real-time. The resulting routing table can be used with existing
routers without needing any change in architecture. However, by realizing the IP
routing table as proposed in this thesis, the implementation requires less complex
hardware than Ternary CAM (TCAM) which are traditionally used to implement IP
routing tables. The proposed architecture also reduces lookup latency by about 46%,
hardware area by 9% and power consumed by 15% in contrast to a TCAM based
implementation.
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A CAD tool for current-mode multiple-valued CMOS circuitsLee, Hoon S. 12 1900 (has links)
Approved for public release; distribution is unlimited / The contribution of this thesis is the development of a CAD (computer aided
design) tool for current mode multiple-valued logic (MVL) CMOS circuits. It is
only the second known MVL CAD tool and the first CAD tool for MVL CMOS.
The tool accepts a specification of the function to be realized by the user,
produces a minimal or near-minimal realization (if such a realization is possible),
and produces a layout of a programmable logic array (PLA) integrated circuit that
realizes the given function. The layout is in MAGIC format, suitable for submission
to a chip manufacturer. The CAD tool also allows the user to simulate the realized
function so that he/she can verify correctness of design.
The CAD tool is designed also to be an analysis tool for heuristic minimization
algorithms. As part of this thesis, a random function generator and statistics gathering
package were developed. In the present tool, two heuristics are provided and
the user can choose one or both. In the latter case, the better realization is output
to the user. The CAD tool is designed to be flexible, so that future improvements
can be made in the heuristic algorithms, as well as the layout generator. Thus,
the tool can be used to accommodate new technologies, for example, a voltage mode
CMOS PLA rather than the current mode CMOS currently implemented. / http://archive.org/details/cadtoolforcurren00leeh / Lieutenant, Republic of Korea Navy
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