• Title/Summary/Keyword: Clock performance

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On the Performance Enhancements of VC Merging-capable Scheduler for MPLS Routers by Sequence Skipping Method (Sequence Skipping 방법을 이용한 MPLS 라우터의 VC 통합기능 스케쥴러의 성능 향상에 관한 연구)

  • Baek, Seung-Chan;Park, Do-Yong;Kim, Young-Beom
    • Journal of IKEEE
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    • v.5 no.1 s.8
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    • pp.111-120
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    • 2001
  • VC merging involves distinguishing cells from an identical merged VC label. Various approaches have been proposed to help this identification process. However, most of them incur additional buffering, protocol overhead and/or variable delay. They make the provision of QoS difficult to achieve. So it was proposed a merge capable scheduler to support VC-merging (VCMS). However, in situations where all VCs are to be merged or the incoming traffic load is very low, it could happen that there are not enough non-merging cells to snoop. In this situation the scheduler uses special control cells to fill the empty time slots out. Too many control cells can cause high cell loss ratio and an additional packet transfer delay. To overcome the drawbacks, we propose a Sequence Skipping(SS) method where the sequencers skip the empty queues and insert SS cells. We show SS method is suitable for VC-merging and can reduce the cell loss ratio and the mean packet transfer delay through simulations.

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FPGA Design of SVM Classifier for Real Time Image Processing (실시간 영상처리를 위한 SVM 분류기의 FPGA 구현)

  • Na, Won-Seob;Han, Sung-Woo;Jeong, Yong-Jin
    • Journal of IKEEE
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    • v.20 no.3
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    • pp.209-219
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    • 2016
  • SVM is a machine learning method used for image processing. It is well known for its high classification performance. We have to perform multiple MAC operations in order to use SVM for image classification. However, if the resolution of the target image or the number of classification cases increases, the execution time of SVM also increases, which makes it difficult to be performed in real-time applications. In this paper, we propose an hardware architecture which enables real-time applications using SVM classification. We used parallel architecture to simultaneously calculate MAC operations, and also designed the system for several feature extractors for compatibility. RBF kernel was used for hardware implemenation, and the exponent calculation formular included in the kernel was modified to enable fixed point modelling. Experimental results for the system, when implemented in Xilinx ZC-706 evaluation board, show that it can process 60.46 fps for $1360{\times}800$ resolution at 100MHz clock frequency.

High-Performance Line-Based Filtering Architecture Using Multi-Filter Lifting Method (다중필터 리프팅 방식을 이용한 고성능 라인기반 필터링 구조)

  • 서영호;김동욱
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.41 no.8
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    • pp.75-84
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    • 2004
  • In this paper, we proposed an efficient hardware architecture of line-based lifting algorithm for Motion JPEG2000. We proposed a new architecture of a lifting-based filtering cell which has an optimized and simplified structure. It was implemented in a hardware accommodating both (9,7) and (5,4) filter. Since the output rate is linearly proportional to the input rate, one can obtain the high throughput through parallel operation simply by adding the hardware units. It was implemented into both of ASIC and FPGA The 0.35${\mu}{\textrm}{m}$ CMOS library from Samsung was used for ASIC and Altera was the target for FRGA. In ASIC, the proposed architecture used 41,592 gates for the lifting arithmetic and 128 Kbit memory. For FPGA it used 6,520 LEs(Logic Elements) and 128 ESBs(Embedded System Blocks). The implementations were stably operated in the clock frequency of 128MHz and 52MHz, respectively.

A Design of AES-based CCMP Core for IEEE 802.11i Wireless LAN Security (IEEE 802.11i 무선 랜 보안을 위한 AES 기반 CCMP Core 설계)

  • Hwang, Seok-Ki;Lee, Jin-Woo;Kim, Chay-Hyeun;Song, You-Soo;Shin, Kyung-Wook
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.1
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    • pp.367-370
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    • 2005
  • This paper describes a design of AES(Advanced Encryption Standard)-based CCMP core for IEEE 802.11i wireless LAN security. To maximize its performance, two AES cores are used, one is for counter mode for data confidentiality and the other is for CBC(Cipher Block Chaining)mode for authentication and data integrity. The S-box that requires the largest hardware in AES core is implemented using composite field arithmetic, and the gate count is reduced by about 25% compared with conventional LUT(Lookup Table)-based design. The CCMP core designed in Verilog-HDL has 15,450 gates, and the estimated throughput is about 128 Mbps at 50-MHz clock frequency). The functionality of the CCMP core is verified by Excalibur SoC implementation.

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VLIS Design of OCB-AES Cryptographic Processor (OCB-AES 암호 프로세서의 VLSI 설계)

  • Choi Byeong-Yoon;Lee Jong-Hyoung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.9 no.8
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    • pp.1741-1748
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    • 2005
  • In this paper, we describe VLSI design and performance evaluation of OCB-AES crytographic algorithm that simulataneously provides privacy and authenticity. The OCB-AES crytographic algorithm sovles the problems such as long operation time and large hardware of conventional crytographic system, because the conventional system must implement the privancy and authenticity sequentially with seqarated algorithms and hardware. The OCB-AES processor with area-efficient modular offset generator and tag generator is designed using IDEC Samsung 0.35um standard cell library and consists of about 55,700 gates. Its cipher rate is about 930Mbps and the number of clock cycles needed to generate the 128-bit tags for authenticity and integrity is (m+2)${\times}$(Nr+1), where m and Nr represent the number of block for message and number of rounds for AES encryption, respectively. The OCB-AES processor can be applicable to soft cryptographic IP of IEEE 802.11i wireless LAN and Mobile SoC.

A Study on Area-Efficient Design of Unified MD5 and HAS-160 Hash Algorithms (MD5 및 HAS-160 해쉬 알고리즘을 통합한 면적 효율적인 설계에 관한 연구)

  • Sonh, Seung-Il
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.5
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    • pp.1015-1022
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    • 2012
  • This paper deals with hardware design which unifies MD5 and HAS-160 hash algorithms. Two algorithms get a message with arbitrary length and process message blocks divided into 512 bits each time and output a hash code with a fixed length. MD5 ouputs a hash code of 128 bits and HAS-160 a hash code of 160 bits. The unified hash core designed has 32% of slices overhead compared to HAS-160 core. However, there is only a fixed message buffer space used. The unified hash core which run a step in one clock cycle operates at 92MHz and has performance which digests a message in the speed of 724Mbps at MD5 and 581Mbps at HAS-160 hash mode. The unified hash core which is designed can be applicable to the areas such as E-commerce, data integrity and digital signature.

Federated Filter Approach for GNSS Network Processing

  • Chen, Xiaoming;Vollath, Ulrich;Landau, Herbert
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.1
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    • pp.171-174
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    • 2006
  • A large number of service providers in countries all over the world have established GNSS reference station networks in the last years and are using network software today to provide a correction stream to the user as a routine service. In current GNSS network processing, all the geometric related information such as ionospheric free carrier phase ambiguities from all stations and satellites, tropospheric effects, orbit errors, receiver and satellite clock errors are estimated in one centralized Kalman filter. Although this approach provides an optimal solution to the estimation problem, however, the processing time increases cubically with the number of reference stations in the network. Until now one single Personal Computer with Pentium 3.06 GHz CPU can only process data from a network consisting of no more than 50 stations in real time. In order to process data for larger networks in real time and to lower the computational load, a federated filter approach can be considered. The main benefit of this approach is that each local filter runs with reduced number of states and the computation time for the whole system increases only linearly with the number of local sensors, thus significantly reduces the computational load compared to the centralized filter approach. This paper presents the technical aspect and performance analysis of the federated filter approach. Test results show that for a network of 100 reference stations, with the centralized approach, the network processing including ionospheric modeling and network ambiguity fixing needs approximately 60 hours to process 24 hours network data in a 3.06 GHz computer, which means it is impossible to run this network in real time. With the federated filter approach, only less than 1 hour is needed, 66 times faster than the centralized filter approach. The availability and reliability of network processing remain at the same high level.

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A FPGA Implementation of BIST Design for the Batch Testing (일괄검사를 위한 BIST 설계의 FPGA 구현)

  • Rhee, Kang-Hyeon
    • The Transactions of the Korea Information Processing Society
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    • v.4 no.7
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    • pp.1900-1906
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    • 1997
  • In this paper, the efficient BILBO(named EBILBO) is designed for BIST that is able to batch the testing when circuit is designed on FPGA. The proposed algorithm of batch testing is able to test the normal operation speed with one-pin-count that can control all part of large and complex circuit. PRTPG is used for the test pattern and MISR is used for PSA. The proposed algorithm of batch testing is VHDL coding on behavioral description, so it is easily modified the model of test pattern generation, signature analysis and compression. The EBILBO's area and the performance of designed BIST are evaluated with ISCAS89 benchmark circuit on FPGA. In circuit with above 600 cells, it is shown that area is reduced below 30%, test pattern is flexibly generated about 500K and the fault coverage is from 88.3% to 100%. EBILBO for the proposed batch testing BIST is able to execute concurrently normal and test mode operation in real time to the number of $s+n+(2^s/2^p-1)$ clock(where, in CUT, # of PI;n, # of register, p is order # of polynomial). The proposed algorithm coded with VHDL is made of library, then it well be widely applied to DFT that satisfy the design and test field on sme time.

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A Radiation-hardened Model Design of CMOS Digital Logic Circuit for Nuclear Power Plant IC and its Total Radiation Damage Analysis (원전용 IC를 위한 CMOS 디지털 논리회로의 내방사선 모델 설계 및 누적방사선 손상 분석)

  • Lee, Min-Woong;Lee, Nam-Ho;Kim, Jong-Yeol;Cho, Seong-Ik
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.6
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    • pp.745-752
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    • 2018
  • ICs(Integrated circuits) for nuclear power plant exposed to radiation environment occur malfunctions and data errors by the TID(Total ionizing dose) effects among radiation-damage phenomenons. In order to protect ICs from the TID effects, this paper proposes a radiation-hardening of the logic circuit(D-latch) which used for the data synchronization and the clock division in the ICs design. The radiation-hardening technology in the logic device(NAND) that constitutes the proposed RH(Radiation-hardened) D-latch is structurally more advantageous than the conventional technologies in that it keeps the device characteristics of the commercial process. Because of this, the unit cell based design of the RH logic device is possible, which makes it easier to design RH ICs, including digital logic circuits, and reduce the time and cost required in RH circuit design. In this paper, we design and modeling the structure of RH D-latch based on commercial $0.35{\mu}m$ CMOS process using Silvaco's TCAD 3D tool. As a result of verifying the radiation characteristics by applying the radiation-damage M&S (Modeling&Simulation) technique, we have confirmed the radiation-damage of the standard D-latch and the RH performance of the proposed D-latch by the TID effects.

Development of Continuous Capture Test Architecture in the Boundary Scan (경계면스캔에서의 연속캡쳐 시험구조 개발)

  • Jhang, Young-Sig;Lee, Chang-Hee
    • The KIPS Transactions:PartA
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    • v.16A no.2
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    • pp.79-88
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    • 2009
  • In boundary scan architecture, test stimuli are shifted in one at a time and applied to the on-chip system logic. The test results are captured into the BSR and are examined by subsequent shifting. In this paper, we developed a continuous capture test architecture and test procedure using TPG based on boundary scan is used to performance test. In this architecture, test patterns of TPG are applied to CUT with system clock rate, and response of CUT is continuously captured by CBSR(Continuous Capture Boundary Scan Register) at the same rate and the captured results is shifted to TDO at the same rate. The suggested a continuous capture test architecture and test procedure is simulated by Altera Max+Plus 10.0. The simulation results shows the accurate operation and effectiveness of the proposed test architecture and procedure.