• Title/Summary/Keyword: I/O interface

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An Implementation of I/O Interface System for Power Plant Simulator (발전소 시뮬레이터 I/O 인터페이스 시스템 구축에 관한 연구)

  • 변승현;장태인;조지용;곽귀일
    • Proceedings of the IEEK Conference
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    • 1999.06a
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    • pp.773-776
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    • 1999
  • For providing good quality power steadily, it is required that operators manipulate the control system of power plant with the good knowledge of power plant system and the control strategies, and cope with accidents effectively. With those requirements, it is general to train operators in power plant control room using full-scope simulator. A full scope simulator adopts the I&C instruments in the main cotrol room, so has to include I/O interface system to interface the simulation computer with I&C instruments in main control room. In already developed simulators, most of I/O interface systems are closed. vendor-dependent. proprietary systems. so have the many disadvantages in terms of cost and maintenance. In this paper. we suggest the method to configure I/O interface system for Thermal Power Plant Simulator based on standard technology which gives the advantages of ease-of-use. cost effectiveness, and simplicity of maintenanceuse by using off-the-shelf products for system integration.

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Optimizing I/O Stack for Fast Storage Devices (고속 저장 장치를 위한 입출력 스택 최적화)

  • Han, Hyuck
    • The Journal of the Korea Contents Association
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    • v.16 no.5
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    • pp.251-258
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    • 2016
  • Recently, the demand for fast storage devices is rapidly increasing in cloud platforms, social network services, etc. Despite the development of fast storage devices, the traditional Linux I/O stack is not able to exploit the full extent of the performance improvement since it has been optimized for disk-based storage devices. In this paper, we propose an optimized I/O stack which can fully utilize the I/O bandwidth and latency of fast storage devices. To this end, we design a new I/O interface to replace the current block I/O interface and optimize our I/O interface. Our optimized I/O interface bypasses operations/layers in block I/O subsystems of the current Linux I/O stack to fully exploit fast storage devices. We also optimize the Linux file systems such as ext2 and ext4 to run on our I/O interface. We evaluate our I/O stack with multiple benchmarks and the experimental results show that our I/O stack achieves 1.7 times better throughput compared to traditional Linux I/O stack.

Development of Realtime Parallel Data Communication Interface for Remote Control of 6-DOF Industrial Robot (산업용 6관절 로봇의 원격제어를 위한 실시간 병렬데이터통신 인터페이스)

  • Choi, Myoung-Hwan;Lee, Woo-Won
    • Journal of Industrial Technology
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    • v.21 no.A
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    • pp.97-103
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    • 2001
  • This paper presents the development of the I/O Interface for the real time parallel data communication between controller of a six-axis industrial robot(CRS-A460) and an external computer. The proposed I/O Interface consists of the hardware I/O interface and the software that is downloaded to the robot controller and executed by the controller operating system. The constitution of the digital I/O Port for CRS-A460 robot controller and the digital I/O board for IBM-PC are presented as well as the Process Control Program of the robot controller. The developed protocol for the parallel data communication is described. The data communication is tested, and the performance is analysed. In particular, it is shown that the real-time constraint of the robot controller process is satisfied.

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LEED I/V Curve Analysis of O/Fe(100) and MgO/Fe(100) System (O/Fe(100) and MgO/Fe(100) 계의 LEED I/V curve 분석)

  • Seo, J.K.;Kim, S.H.
    • Journal of the Korean Vacuum Society
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    • v.16 no.1
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    • pp.1-6
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    • 2007
  • We have analyzed the atomic structure of O/Fe(100) and interface atomic structure of MgO deposited on Fe(100) surface using LEED I/V curve analysis. As the O adsorption on the Fe(100) surface, the first substrate interlayer distance is expanded by up to 16%. For 1ML MgO deposited on Fe(100) surface, the oxygen ions of MgO are located on-top of the Fe atoms, the interlayer distance at the MgO/Fe interface are expanded. From the AIA(average intensity mixing approximation) calculation, we find the interface structure of monolayer MgO on Fe(100) system has the two interface structure with MgO/FeO/Fe(100) and MgO/Fe(100). This supports the results of EELS experiment that shown existence of stretched FeO layer and coexistance of MgO/FeO/Fe(100) and MgO/Fe(100) structure.

Performance Analysis of NVMe SSDs and Design of Direct Access Engine on Virtualized Environment (가상화 환경에서 NVMe SSD 성능 분석 및 직접 접근 엔진 개발)

  • Kim, Sewoog;Choi, Jongmoo
    • KIISE Transactions on Computing Practices
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    • v.24 no.3
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    • pp.129-137
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    • 2018
  • NVMe(Non-Volatile Memory Express) SSD(Solid State Drive) is a high-performance storage that makes use of flash memory as a storage cell, PCIe as an interface and NVMe as a protocol on the interface. It supports multiple I/O queues which makes it feasible to process parallel-I/Os on multi-core environments and to provide higher bandwidth than SATA SSDs. Hence, NVMe SSD is considered as a next generation-storage for data-center and cloud computing system. However, in the virtualization system, the performance of NVMe SSD is not fully utilized due to the bottleneck of the software I/O stack. Especially, when it uses I/O stack of the hypervisor or the host operating system like Xen and KVM, I/O performance degrades seriously due to doubled-I/O stack between host and virtual machine. In this paper, we propose a new I/O engine, called Direct-AIO (Direct-Asynchronous I/O) engine, that can access NVMe SSD directly for I/O performance improvements on QEMU emulator. We develop our proposed I/O engine and analyze I/O performance differences between the existed I/O engine and Direct-AIO engine.

An I/O Interface Circuit Using CTR Code to Reduce Number of I/O Pins (CTR 코드를 사용한 I/O 핀 수를 감소 시킬 수 있는 인터페이스 회로)

  • Kim, Jun-Bae;Kwon, Oh-Kyong
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.36D no.1
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    • pp.47-56
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    • 1999
  • As the density of logic gates of VLSI chips has rapidly increased, more number of I/O pins has been required. This results in bigger package size and higher packager cost. The package cost is higher than the cost of bare chips for high I/O count VLSI chips. As the density of logic gates increases, the reduction method of the number of I/O pins for a given complexity of logic gates is required. In this paper, we propose the novel I/O interface circuit using CTR (Constant-Transition-Rate) code to reduce 50% of the number of I/O pins. The rising and falling edges of the symbol pulse of CTR codes contain 2-bit digital data, respectively. Since each symbol of the proposed CTR codes contains 4-bit digital data, the symbol rate can be reduced by the factor of 2 compared with the conventional I/O interface circuit. Also, the simultaneous switching noise(SSN) can be reduced because the transition rate is constant and the transition point of the symbols is widely distributed. The channel encoder is implemented only logic circuits and the circuit of the channel decoder is designed using the over-sampling method. The proper operation of the designed I/O interface circuit was verified using. HSPICE simulation with 0.6 m CMOS SPICE parameters. The simulation results indicate that the data transmission rate of the proposed circuit using 0.6 m CMOS technology is more than 200 Mbps/pin. We implemented the proposed circuit using Altera's FPGA and confimed the operation with the data transfer rate of 22.5 Mbps/pin.

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Design of Web Based Parallel I/O Control System Using IEEE 1284 Operating Modes (IEEE 1284 동작 모드를 사용하는 웹 기반 병렬 I/O 제어 장치의 설계)

  • Chang, Ho-Sung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.3
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    • pp.991-996
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    • 2010
  • In this paper, we designed a parallel I/O control system using IEEE 1284 operating modes and implemented remote control communication under the internet environment. The IEEE 1284 standard defines an interface compatible with several distinct operation modes and brings higher performance to the PC parallel port. Therefore, parallel port devices become easier to configure and simplify interface because new operating systems bring PnP function to the parallel port with the Device/ID identification sequence. With these enhancements, the parallel port become an even better low-cost, readily available I/O port on the PC.

Effect of Interface Reaction between ZnO:Al and Amorphous Silicon on Silicon Heterojunction Solar Cells (실리콘 이종 접합 태양 전지 특성에 대한 ZnO:Al과 비정질 실리콘 계면 반응의 영향)

  • Kang, Min-Gu;Tark, Sung-Ju;Lee, Jong-Han;Kim, Chan-Seok;Jung, Dae-Young;Lee, Jung-Chul;Yoon, Kyung-Hoon;Kim, Dong-Hwan
    • Korean Journal of Materials Research
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    • v.21 no.2
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    • pp.120-124
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    • 2011
  • Silicon heterojunction solar cells have been studied by many research groups. In this work, silicon heterojunction solar cells having a simple structure of Ag/ZnO:Al/n type a-Si:H/p type c-Si/Al were fabricated. Samples were fabricated to investigate the effect of transparent conductive oxide growth conditions on the interface between ZnO:Al layer and a-Si:H layer. One sample was deposited by ZnO:Al at low working pressure. The other sample was deposited by ZnO:Al at alternating high working pressure and low working pressure. Electrical properties and chemical properties were investigated by light I-V characteristics and AES method, respectively. The light I-V characteristics showed better efficiency on sample deposited by ZnO:Al by alternating high working pressure and low working pressure. Atomic concentrations and relative oxidation states of Si, O, and Zn were analyzed by AES method. For poor efficiency samples, Si was diffused into ZnO:Al layer and O was diffused at the interface of ZnO:Al and Si. Differentiated O KLL spectra, Zn LMM spectra, and Si KLL spectra were used for interface reaction and oxidation state. According to AES spectra, sample deposited by high working pressure was effective at reducing the interface reaction and the Si diffusion. Consequently, the efficiency was improved by suppressing the SiOx formation at the interface.

Design of Electronic Control Unit for Parking Assist System (주차 보조 시스템을 위한 ECU 설계)

  • Choi, Jin-Hyuk;Lee, Seongsoo
    • Journal of IKEEE
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    • v.24 no.4
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    • pp.1172-1175
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    • 2020
  • Automotive ECU integrates CPU core, IVN controller, memory interface, sensor interface, I/O interface, and so on. Current automotive ECUs are often developed with proprietary processor architectures. However, demends for standard processors such as ARM and RISC-V increase rapidly for saftware compatibility in autonomous vehicles and connected cars. In this paper, an automotive ECU is designed for parking assist system based on RISC-V with open instruction set architecture. It includes 32b RISC-V CPU core, IVN controllers such as CAN and LIN, memory interfaces such as ROM and SRAM, and I/O interfaces such as SPI, UART, and I2C. Fabricated in 65nm CMOS technology, its operating frequency, area, and gate count are 50MHz, 0.37㎟, and 55,310 gates, respectively.

SiC/SiO2 Interface Characteristics in N-based 4H-SiC MOS Capacitor Fabricated with PECVD and NO Annealing Processes (PECVD와 NO 어닐링 공정을 이용하여 제작한 N-based 4H-SiC MOS Capacitor의 SiC/SiO2 계면 특성)

  • Song, Gwan-Hoon;Kim, Kwang-Soo
    • Journal of IKEEE
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    • v.18 no.4
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    • pp.447-455
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    • 2014
  • In this research, n-based 4H-MOS Capacitor was fabricated with PECVD (plasma enhanced chemical vapor deposition) process for improving SiC/$SiO_2$ interface properties known as main problem of 4H-SiC MOSFET. To overcome the problems of dry oxidation process such as lower growth rate, high interface trap density and low critical electric field of $SiO_2$, PECVD and NO annealing processes are used to MOS Capacitor fabrication. After fabrication, MOS Capacitor's interface properties were measured and evaluated by hi-lo C-V measure, I-V measure and SIMS. As a result of comparing the interface properties with the dry oxidation case, improved interface and oxide properties such as 20% reduced flatband voltage shift, 25% reduced effective oxide charge density, increased oxide breakdown field of 8MV/cm and best effective barrier height of 1.57eV, 69.05% reduced interface trap density in the range of 0.375~0.495eV under the conduction band are observed.