• Title, Summary, Keyword: Flash Memory

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PMBIST for NAND Flash Memory Pattern Test (NAND Flash Memory Pattern Test를 위한 PMBIST)

  • Kim, Tae-Hwan;Chang, Hoon
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.1
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    • pp.79-89
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    • 2014
  • It has been an increase in consumers who want a high-capacity and fast speed by the newly diffused mobile device(Smart phones, Ultra books, Tablet PC). As a result, the demand for Flash Memory is constantly increasing. Flash Memory is separated by a NAND-type and NOR-type. NAND-type Flash Memory speed is slow, but price is cheaper than the NOR-type Flash Memory. For this reason, NAND-type Flash Memory is widely used in the mobile market. So Fault Detection is very important for Flash Memory Test. In this paper, Proposed PMBIST for Pattern Test of NAND-type Flash Memory improved Fault detection.

Design and Implementation of an Efficient FTL for Large Block Flash Memory using Improved Hybrid Mapping (향상된 혼합 사상기법을 이용한 효율적인 대블록 플래시 메모리 변환계층 설계 및 구현)

  • Park, Dong-Joo;Kwak, Kyoung-Hoon
    • Journal of KIISE:Computing Practices and Letters
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    • v.15 no.1
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    • pp.1-13
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    • 2009
  • Flash memory is widely used as a storage medium of mobile devices such as MP3 players, cellular phones and digital cameras due to its tiny size, low power consumption and shock resistant characteristics. Currently, there are many studies to replace HDD with flash memory because of its numerous strong points. To use flash memory as a storage medium, FTL(Flash Translation Layer) is required since flash memory has erase-before-write constraints and sizes of read/write unit and erase unit are different from each other. Recently, new type of flash memory called "large block flash memory" is introduced. The large block flash memory has different physical structure and characteristics from previous flash memory. So existing FTLs are not efficiently operated on large block flash memory. In this paper, we propose an efficient FTL for large block flash memory based on FAST(Fully Associative Sector Translation) scheme and page-level mapping on data blocks.

Memory Compaction Scheme with Block-Level Buffer for Large Flash Memory

  • Chung, Weon-Il;Li, Liangbo
    • International Journal of Contents
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    • v.6 no.4
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    • pp.22-29
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    • 2010
  • In flash memory, many previous garbage collection methods only merge blocks statically and do not consider the contents of buffer. These schemes may cause more unnecessary block erase operations and page copy operations. However, since flash memory has the limitation of maximum rate and life cycle to delete each block, an efficient garbage collection method to evenly wear out the flash memory region is needed. This paper proposes a memory compaction scheme based on block-level buffer for flash memory. The proposed scheme not only merges the data blocks and the corresponding log block, but also searches for the block-level buffer to find the corresponding buffer blocks. Consequently, unnecessary potential page copying operations and block erasure operations could be reduced, thereby improving the performance of flash memory and prolonging the lifetime of flash memory.

A Design of a Flash Memory Swapping File System using LFM (LFM 기법을 이용한 플래시 메모리 스와핑 파일 시스템 설계)

  • Han, Dae-Man;Koo, Yong-Wan
    • Journal of Internet Computing and Services
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    • v.6 no.4
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    • pp.47-58
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    • 2005
  • There are two major type of flash memory products, namely, NAND-type and NOR-type flash memory. NOR-type flash memory is generally deployed as ROM BIOS code storage because if offers Byte I/O and fast read operation. However, NOR-type flash memory is more expensive than NAND-type flash memory in terms of the cost per byte ratio, and hence NAND type flash memory is more widely used as large data storage such as embedded Linux file systems. In this paper, we designed an efficient flash memory file system based an Embedded system and presented to make up for reduced to Swapping a weak System Performance to flash file system using NAND-type flash memory, then proposed Swapping algorithm insured to an Execution time. Based on Implementation and simulation studies, Then, We improved performance bases on NAND-type flash memory to the requirement of the embedded system.

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Regular File Access of Embedded System Using Flash Memory as a Storage (플래시 메모리를 저장매체로 사용하는 임베디드 시스템에서의 정규파일 접근)

  • 이은주;박현주
    • Journal of Information Technology Applications and Management
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    • v.11 no.1
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    • pp.189-200
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    • 2004
  • Recently Flash Memory which is small and low-powered is widely used as a storage of embedded system, because an embedded system requests portability and a fast response. To resolve a difference of access time between a storage and RAM, Linux is using disk caching which copies a part of file on disk into RAM. It is not also an exception on embedded system. A READ access-time of flash memory is similar to RAMs. So, when a process on an embedded system reads data, it is similar to the time to access cached data in RAM and to access directly data on a flash memory. On the embedded system using limited memory, using a disk cache is that wastes much time and memory spaces to manage it and can not reflects the characteristic of a flash memory. This paper proposes the regular file access of limited using a page cache in the file system based on a flash memory and reflects the characteristic of a flash memory. The proposed algorithm minimizes power consumption because access numbers of the RAM are reduced and doesn't waste a memory space because it accesses directly to a flash memory Therefore, the performance improvement of the system applying the proposed algorithm is expected.

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A Technique to Enhance Performance of Log-based Flash Memory File Systems (로그기반 플래시 메모리 파일 시스템 성능 향상 기법)

  • Ryu, Junkil;Park, Chanik
    • IEMEK Journal of Embedded Systems and Applications
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    • v.2 no.3
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    • pp.184-193
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    • 2007
  • Flash memory adoption in the mobile devices is increasing or vanous multimedia services such as audio, videos, and games. Although the traditional research issues such as out-place update, garbage collection, and wear-leveling are important, the performance, memory usage, and fast mount issues of flash memory file system are becoming much more important than ever because flash memory capacity is rapidly increasing. In this paper, we address the problems of the existing log-based flash memory file systems analytically and propose an efficient log-based file system, which produces higher performance, less memory usage and mount time than the existing log-based file systems. Our ideas are applied to a well-known log-based flash memory file system (YAFFS2) and the performance tests are conducted by comparing our prototype with YAFFS2. The experimental results show that our prototype achieves higher performance, less system memory usage, and faster mounting than YAFFS2, which is better than JFFS2.

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Development of a Flash Memory Drive for ATA bus (ATA 버스 방식을 위한 Flash Memory Drive 개발)

  • Kang, Kyung-Sik;Jang, Moon-Kee;Hwang, Yeon-Bum;Jung, Nam-Mo;Park, Jin-Soo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.1
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    • pp.547-550
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    • 2005
  • This treatise studies and developed flash memory drive of ATA bus that use flash memory which is employment amount memory semiconductor to improve problem of hard-disk that is existing ATA bus. While general hard-disk is sensitive external impact or shock, but flash memory drive do save chapter as well as is strong in external impact using semiconductor memory element that disk is not low electric power, light weight possible . Practical use is expected do save chapter for embedded system or black box for vehicles, soldiers hereafter therefore.

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A Study of HDD Performance Improvement through Filter Driver & NAND FLASH Memory (Filter Driver 와 NAND FLASH Memory를 이용한 HDD 장치의 성능 개선에 관한 연구)

  • Kim, Jae-Kyung;Kim, Woo-Gil;Kim, Young-Kil
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.8
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    • pp.1635-1641
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    • 2011
  • In this paper, we research the method for HDD I/O Performance improvement by Filter Driver & NAND FLASH Memory. This paper was started from NAND Flash Memory can not be replaced by HDD because of high cost. So We consider that using NAND Flash Memory as cache for HDD. It can be achieved high HDD Performance through Filter Driver by low cost.

Duplication-Aware Garbage Collection for Flash Memory-Based Virtual Memory Systems (플래시 메모리 기반의 가상 메모리 시스템을 위한 중복성을 고려한 GC 기법)

  • Ji, Seung-Gu;Shin, Dong-Kun
    • Journal of KIISE:Computer Systems and Theory
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    • v.37 no.3
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    • pp.161-171
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    • 2010
  • As embedded systems adopt monolithic kernels, NAND flash memory is used for swap space of virtual memory systems. While flash memory has the advantages of low-power consumption, shock-resistance and non-volatility, it requires garbage collections due to its erase-before-write characteristic. The efficiency of garbage collection scheme largely affects the performance of flash memory. This paper proposes a novel garbage collection technique which exploits data redundancy between the main memory and flash memory in flash memory-based virtual memory systems. The proposed scheme takes the locality of data into consideration to minimize the garbage collection overhead. Experimental results demonstrate that the proposed garbage collection scheme improves performance by 37% on average compared to previous schemes.

Performane Modeling of Flash Memory Storage Systems Using Simulink (시뮬링크를 이용한 플래시메모리 저장장치 성능 모델링)

  • Min, Hang Jun;Park, Jeong Su;Lee, Joo Il;Min, Sang Lyul;Kim, Kanghee
    • IEMEK Journal of Embedded Systems and Applications
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    • v.6 no.5
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    • pp.263-272
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    • 2011
  • The complexity of flash memory based storage systems is high due to diverse host interfaces and other design choices such as mapping granularity, flash memory controller execution models and so on. Thus, it is possible that the actual performance after implementation is not consistent with the target performance. This paper demonstrates that the performance prediction of flash memory based storage systems is possible through performance modeling that takes into account various design parameters. In the performance modeling, the FTL, which is the core element of flash memory based storage systems, is modeled as a set of (copy-on-write) logs and their interactions. Also, the flash memory controller is modeled based on the classification proposed in the design of the Ozone flash controller. In this study, the performance model has been implemented using Simulink and experimental results are presented and analyzed.