• Journal of Korea Society of Industrial Information Systems
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• v.18 no.5
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• pp.33-37
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• 2013

In this paper, we introduce a SDRAM controller implemented on FPGA. Modern embedded system adopts SDRAM as a memory to meet the high capacity memory demands. Our SDRAM controller is written in Verilog and verified on an FPGA, demonstrating the functionality along with ARM Cortex-M0, supporting AMBA AHB.

• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.1209-1212
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• 2003

In this paper, we propose a SDRAM Controller. The SDRAM is often used a mainstream memory as embedded system memory due to its short latency, burst access and pipeline features. The proposed Controller provides essential functions for SDRAM initialization, read/write accesses, memory refresh and Burst access. Furthermore, the proposed controller is implemented in the form of SOFT IP. Therefore, it reduces the designer's effort greatly.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.753-756
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• 1999

In this research we designed and synthesized an effective Synchronous DRAM controller for Interleaved Column Mode Access with VHDL. When target device was ALTERA CPLD MA$\times$712 105 logic cells were used. The result of the simulation at 66MHz clock operation, the clock-to-output time t$_{co}$ was 4.5㎱ and the SDRAM controller was in good working order.r. good working order.

• Journal of Advanced Navigation Technology
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• v.15 no.6
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• pp.1104-1110
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• 2011

The conventional semiconductor equipment has adopted SRAM module as the test pattern memory, which has a simple design and does not require refreshing. However, SRAM has its disadvantages as it takes up more space as its capacity becomes larger, making it difficult to meet the requirements of large memories and compact size. if DRAM is adopted as the semiconductor inspection equipment, it takes up less space and costs less than SRAM. However, DRAM is also disadvantageous because it requires the memory cell refresh, which is not suitable for the semiconductor examination equipments that require correct timing. Therefore, In this paper, we will proposed an algorithm for punctuality guarantee of memory-free inspection equipment using DDR2 SDRAM. And we will Developed memory controller using punctuality guarantee algorithm. As the results, show that when we adopt the DDR2 SDRAM, we can get the benefits of saving 13.5 times and 5.3 times in cost and space, respectively, compared to the SRAM.

• ETRI Journal
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• v.32 no.1
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• pp.84-92
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• 2010

This paper proposes the semaphore authority management (SAM) controller to optimize the dual-port SDRAM (DPSDRAM) in the mobile multimedia systems. Recently, the DPSDRAM with a shared bank enabling the exchange of data between two processors at high speed has been developed for mobile multimedia systems based on dual-processors. However, the latency of DPSDRAM caused by the semaphore for preventing the access contention at the shared bank slows down the data transfer rate and reduces the memory bandwidth. The methodology of SAM increases the data transfer rate by minimizing the semaphore latency. The SAM prevents the latency of reading the semaphore register of DPSDRAM, and reduces the latency of waiting for the authority of the shared bank to be changed. It also reduces the number of authority requests and the number of times authority changes. The experimental results using a 1 Gb DPSDRAM (OneDRAM) with the SAM controllers at 66 MHz show 1.6 times improvement of the data transfer rate between two processors compared with the traditional controller. In addition, the SAM shows bandwidth enhancement of up to 38% for port A and 31% for port B compared with the traditional controller.

• The Journal of the Acoustical Society of Korea
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• v.20 no.1E
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• pp.14-19
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• 2001

We have proposed BIST method and circuit for embedded 16M SDRAM with logic. It can test the AC parameter of embedded 16M SDRAM using the BIST circuit capable of detecting the address of a fail cell installed in an Merged Memory with Logic(MML). It generates the information of repair for redundancy circuit. The function and AC parameter of the embedded memory can also be tested using the proposed BIST method. It is possible to test the embedded SDRAM without external test pin. The total gate of the BIST circuit is approximately 4,500 in the case of synthesizing by 0.25μm cell library and is verified by Verilog simulation. The test time of each one AC parameter is about 200ms using 2Y-March 14n algorithm.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.136-139
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• 2011

The conventional semiconductor equipment has adopted SRAM module as the test pattern memory, which has a simple design and does not require refreshing. However, SRAM has its disadvantages as it takes up more space as its capacity becomes larger, making it difficult to meet the requirements of large memories and compact size. if DRAM is adopted as the semiconductor inspection equipment, it takes up less space and costs less than SRAM. However, DRAM is also disadvantageous because it requires the memory cell refresh, which is not suitable for the semiconductor examination equipments that require correct timing. Therefore, In this paper, we will proposed an algorithm for punctuality guarantee of memory-free inspection equipment using DDR2 SDRAM. And we will produced memory controller using punctuality guarantee algorithm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.1
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• pp.175-182
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• 2011

In this paper, we implemented a high-performence memory controller which can accommodate processing blocks(multiple masters) in SoC for video signal processing. The memory controller is arbitrated by the internal arbiter which receives request signals from masters and sends grant and data signals to masters. The designed memory controller consists of Master Selector, Mster Arbiter, Memory Signal Generator, Command Decoder, and memory Signal Generator. It was designed using VHDL, and verified using the memory model of SAMSING Inc. For FPGA synthesis and verification, Quartus II of ATERA Inc. was used. The target device is Cyclone II. For simulation, ModelSim of Cadence Inc was used. Since the designed H/W can be stably operated in 174.28MHz, it satisfies the specification of SDRAM technology.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.8
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• pp.54-60
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• 2008

The bus architecture consists of a master initiating a communication transaction, a slave responding to the transaction, a arbiter selecting a master, a bridge connecting buses and so on. Recently this is more complicated and developed toward multi-bus architecture. In this paper, several cases of multi-shared bus architecture are discussed and in order to decrease the bridge latency, the architecture introducing a memory selector is proposed. Finally, a LCD controller using DMA master is integrated in this bus architecture that is verified due to RTL simulation and FPGA board test. DMA, LCD line buffer and SDRAM controller are normally operated in the timing simulation using ModelSim tool, and the LCD image is confirmed in the real FPGA board containing LCD panel.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2010.07a
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• pp.411-414
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• 2010

본 논문은 비디오 처리를 위한 고성능의 메모리 제어기를 설계하였다. 메모리 제어기는 arbiter에 의해 제어되며 이것은 메모리 억세스를 요구하는 모듈들의 요구 신호를 받아 데이터를 전송하는 역할을 해주게 된다. 구현된 메모리 제어기는 버스를 사용하기 위한 승인을 받기 위해서 마스터와 신호를 주고 받는 MAU블록, grant 신호를 디코딩하고 컨트롤 신호의 상태를 정의한 arbiter 블록, SDRAM의 ac parameter를 저장하고 bank의 준비 여부, read/write 가능 여부, precharge와 refresh의 가능 여부를 확인하여 system과 read/write가 준비되었다는 신호를 출력, SDRAM의 실질적인 입력신호를 생성하는 memory accelerator 블록, 생성된 입력신호를 저장하고 마스터에서 직접 write data를 입력 받는 memory I/F 블록으로 구성된다. 이 메모리 제어기는 174.28MHz의 주파수로 동작하였다. 본 설계는 VHDL을 이용하여 설계되었고, ALTERA의 Quartus II를 이용하여 합성하였다. 또한 ModelSim을 이용하여 설계된 회로를 검증하였다. 구현된 하드웨어는 StatixIII EP3SE80F1152C2 칩을 사용하였다.