Conventional reconfigurable components have substantially more interconnect configuration bits than they strictly need. Using counting arguments we can establish loose bounds on the number of programmable bits actuall...
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ISBN:
(纸本)9780897917735
Conventional reconfigurable components have substantially more interconnect configuration bits than they strictly need. Using counting arguments we can establish loose bounds on the number of programmable bits actually required to describe an interconnect. We apply these bounds in crude form to some existing devices, demonstrating the large redundancy in their programmable bit streams. In this process we review and demonstrate basic counting techniques for identifying the information required to specify an interconnect. We examine several common interconnect building blocks and look at how efficiently they use the information present in their programming bits. We also discuss the impact of this redundancy on important device aspects such as area, routing, and reconfiguration time.
In this paper, we present and analyze a sophisticated communication architecture that allows to integrate many different modules into a system by FPGA reconfiguration at runtime. Furthermore, we examine how this archi...
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ISBN:
(纸本)9781605584102
In this paper, we present and analyze a sophisticated communication architecture that allows to integrate many different modules into a system by FPGA reconfiguration at runtime. Furthermore, we examine how this architecture can be implemented on low-cost Spartan-3 devices. It will be demonstrated that modules can be exchanged in a system without disturbing the communication architecture. The paper points out, that the capabilities of Spartan-3 FPGAs are sufficient to build complex reconfigurable systems. Copyright 2009 acm.
Good FPGA placement is crucial to obtain the best Quality of Results (QoR) from FPGA hardware. Although many published global placement techniques place objects in a continuous ASIC-like environment, FPGAs are discret...
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ISBN:
(纸本)9781450311557
Good FPGA placement is crucial to obtain the best Quality of Results (QoR) from FPGA hardware. Although many published global placement techniques place objects in a continuous ASIC-like environment, FPGAs are discrete in nature, and a continuous algorithm cannot always achieve superior QoR by itself. Therefore, discrete FPGA-specific detail placement algorithms are used to improve the global placement results. Unfortunately, most of these detail placement algorithms do not have a global view. This paper presents a discrete "middle" placer that fills the gap between the two placement steps. It works like simulated annealing, but leverages various acceleration techniques. It does not pay the runtime penalty typical of simulated annealing solutions. Experiments show that with this placer, final QoR is significantly better than with the global-detail placer approach.
In this paper, we present a new retiming-based technology mapping algorithm for look-up table-based fieldprogrammablegatearrays. The algorithm is based on a novel iterative procedure for computing all k-cuts of all...
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In this paper, we present a new retiming-based technology mapping algorithm for look-up table-based fieldprogrammablegatearrays. The algorithm is based on a novel iterative procedure for computing all k-cuts of all nodes in a sequential circuit, in the presence of retiming. The algorithm completely avoids flow computation which is the bottleneck of previous algorithms. Due to the fact that k is very small in practice, the procedure for computing all k-cuts is very fast. Experimental results indicate the overall algorithm is very efficient in practice.
This paper describes a technique that reduces dynamic power in FPGAs by reducing the number of glitches in the global routing resources. The technique involves adding programmable delay elements within the logic block...
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ISBN:
(纸本)9781595936004
This paper describes a technique that reduces dynamic power in FPGAs by reducing the number of glitches in the global routing resources. The technique involves adding programmable delay elements within the logic blocks of an FPGA to programmably align the arrival times of early-arriving signals to the inputs of the lookup tables and to filter out glitches generated by earlier circuitry. On average, the proposed technique eliminates 91% of the glitching, which reduces overall FPGA power by 18%. The added circuitry increases overall area by 5% and critical-path delay by less than 1%. Furthermore, since it is applied after routing, the proposed technique requires no modifications to the existing FPGA routing architecture or CAD flow.
Glitches are unnecessary transitions on logic signals that needlessly consume dynamic power. Glitches arise from imbalances in the combinational path delays to a signal, which may cause the signal to toggle multiple t...
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ISBN:
(纸本)9781450338561
Glitches are unnecessary transitions on logic signals that needlessly consume dynamic power. Glitches arise from imbalances in the combinational path delays to a signal, which may cause the signal to toggle multiple times in a given clock cycle before settling to its final value. In this paper, we propose a low-cost circuit structure that is able to eliminate a majority of glitches. The structure, which is incorporated into the output buffers of FPGA logic elements, suppresses pulses on buffer outputs whose duration is shorter than a configurable time window (set at the time of FPGA configuration). Glitches are thereby eliminated "at the source" ensuring they do not propagate into the high-capacitance FPGA interconnect, saving power. An experimental study, using Altera commercial tools for power analysis, demonstrates that the proposed technique reduces 70% of glitches, at a cost of 1% reduction in speed performance.
A reconfigurable logic element (LE) is developed for use in constructing a NULL Convention Logic (NCL) FPGA. It can be configured as any of the 27 fundamental NCL gates, including resettable and inverting variations, ...
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ISBN:
(纸本)9781595936004
A reconfigurable logic element (LE) is developed for use in constructing a NULL Convention Logic (NCL) FPGA. It can be configured as any of the 27 fundamental NCL gates, including resettable and inverting variations, and can utilize embedded registration for gates with three or fewer inputs. The developed LE is compared with a previous NCL LE, showing that the one developed herein yields a more area efficient NCL circuit implementation. The NCL FPGA logic element is simulated at the transistor level using the 1.8V, 180nm TSMC CMOS process.
This paper describes an analytical model that relates the architectural parameters of an FPGA to the average prerouting wirelength of an FPGA implementation. Both homogeneous and heterogeneous FPGAs are considered. Fo...
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ISBN:
(纸本)9781605584102
This paper describes an analytical model that relates the architectural parameters of an FPGA to the average prerouting wirelength of an FPGA implementation. Both homogeneous and heterogeneous FPGAs are considered. For homogeneous FPGAs, the model relates the lookup-table size, the cluster size, and the number of inputs per cluster to the expected wirelength. For heterogeneous FPGAs, the number and positioning of the embedded blocks, as well as the number of pins on each embedded block is considered. Two applications of the model to FPGA architectural design are also presented. Copyright 2009 acm.
We present an architecture for a synthesizable datapath-oriented fieldprogrammablegate Array (FPGA) core which can be used to provide post-fabrication flexibility to a System-on-Chip (SoC). Our architecture is optim...
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ISBN:
(纸本)9781595936004
We present an architecture for a synthesizable datapath-oriented fieldprogrammablegate Array (FPGA) core which can be used to provide post-fabrication flexibility to a System-on-Chip (SoC). Our architecture is optimized for bus-based operations that are common in signal processing and computation intensive applications. It employs a directional routing architecture, which allows it to be synthesized using standard ASIC design tools and flows. We also describe a proof-of-concept layout of our core. It is shown that the proposed architecture is significantly more area efficient than the best previously reported synthesizable programmable logic core.
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