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????? Dram DRAM Presentation. History of DRAMWhat is DRAMStructure of DRAMReading data from Dram (DRAM Operations)Comparison DRAM with SRAMSources. ??????? DRAM History of DRAM. Invented in 1966 by Robert Dennard at IBM but The first DRAM was manufactured in 1970 by the then newly formed Intel company, and sold as a product named the 1103 (1 Kbit PMOS dynamic RAM IC), which by 1972 became the best selling semiconductor memory chip in the world,Was the first form of volatile memory for co35334

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    1. ???? ???????? – ???? ????? ???? ????? ???:

    2. ????? Dram DRAM Presentation

    3. ??????? DRAM History of DRAM

    5. What is DRAM Dynamic

    6. Structure of DRAM

    7. Structure of DRAM

    8. Internal blocks Structure of DRAM

    9. Structure of DRAM

    10. Structure of DRAM

    11. The sense amplifier :This block is needed because data bits within the cells are stored with low energies and in weak leaky capacitors, such that data in the memory cells need to be amplifed before they can drive other circuits in the memory.

    12. Address decoders In order to address a cell in the memory cell array, row and column addresses need to be decoded. This takes place in the row and column decoders, respectively. The inputs of the address decoders are cell addresses, while the outputs are called word lines (WLs) in the case of the row decoder, and column select (CS) lines in the case of the column decoder. Each row and column in the memory has a specic line that selects it, and the combination of selecting a row and a column results in selecting a single word in the array. ????????? ???? : ?? ????? ???? ??? ?? ???? ?? ????? ???? ????? (memory cell array)? ???? ??? ???? ??? ??? ? ???? ???????? ???. ??? ??? ?? ????? ??????????? ??? ? ???? ?? ?? ???. ???????? ???? ????????? ???? ??? ???? ?????? ???????? ??????? ?? ???? ??????? ???? word line (WLs) ?????? ????? ? ???? Column Select (cs) ?? ???? ??????? ????? . ?? ??? ? ???? ?? ????? ?? ?? ??? ???? ?? ?? ?????? ?? ???? ? ?????? ?? ?????? ?? ??? ? ?? ???? ???? ???? ??? ?????? ?? ?? word ?? ????? ?? ???.

    13. ???? ??????? ??????? : other functional blocks :The data-in buffers and address buffers are used to latch input data and addresses at the input, while the data-out buffer stores read output data and keeps it for the user on the data bus. ??????? ???? ????? ???? (data-in buffers) ? ??????? ???? (address buffers) ?? ??? ????? ???? ????? ? ???? ?? ?? ?? ????? ??? ???? ?? ????? ??????? ???? ???? ????? ???? (data-out buffer)? ???? ????? ?????? ??? ?? ????? ?? ??? ? ?? ?? ?? ?????? ????? ?? ??? ??? ???? ???? ?? ???.

    14. Structure of DRAM

    18. Reading data from Dram ???? ????? ??? DRAM ?? ?? ?????? ?????? ???? ?? ????? ?????? ?? ????? ??????? ?? ???? ?? ?? ????? ??? ???? ????? ?? .???? ????? ??? ????? ?????? ??? ?? ?? ?? ???? ????? ?? ?????? ???? ?? ????? ?? ?? ???? ????? ???? ?? ??? ? ???? ?? ????? ???? ?? ????? .???? ?????? ??????? ???? ??? ?? ??????? ?? ????? ?? "Row Address Strobe" ?? ?? ???? ?????? "RAS" ?? ?? ?? ??? ?? ?? "/RAS" ???? ???? ?? ??? ?? ????? ???? ?? ???? . ?? ?????? ???? ??????? ????? ?? ?? ???? ?? ????? ????? ??? ??? (sense amplifier (????? ?? ???? .?? ????? ????? ?? ??????CAS ((Column access strobe ?? Dram????? ??? ? ???? ???? ?? ???? ?? ???? ??????? ???? ??? ???? ?????? ?? ???. ??? ?????? ??? ???? ?? ????? ????? ??? ?? ?????? ????? ?? ???. ??? ?????? ?? ??? ?? ?????? ?? ????? ???? ???? ????? ????? ?? ??? .

    19. Reading data from Dram

    20. Step 1(a): Row access strobe (RAS) selects row 2. Reading data from Dram

    21. Step 2(a): Column access strobe (CAS) selects column 1. Reading data from Dram

    28. Comparison DRAM with SRAM Consists of internal latches Each Cell: a 3 state latch Large Cells (4-6 transistors per cell) Smaller Number of Cells per Chip Faster than DRAM More Expensive than DRAM Volatile

    29. DRAM Characteristics

    30. Comparison DRAM with SRAM

    31. ????? ??? SRAM ????? ?? ???????? ?????" ?????? ?? ?????. ?? ??? ??? ?? ????? ?? ?? ???? ???? ???? ????? ???? ?? ??? ????? ??????? ?? ???? ? ???? ??? ??????? ??? ???? ?? ????? ?????. ?? ???? ???? ???? ?? ???? ?????? ?? ???? ?? ?? ?????????? ??????? ?? ??? . ????? ??? SRAM ??????? ???????? / ???????? ??????? ??????? ???? ???????? ???? ??? ??? ?? ????? ?? ?????? ?? ????? ??? DRAM ????? ??? .?? ???? ?? ????? ????? ??? SRAM ?? ??? ??? ?????? ????? ?? ????? ???? ??????? ??? ???? ?? ??? ?? ????? ?????? ????? ?? ?? ???? ????? ?? ??? DRAM ????? ???. ?? ???? ?????? ????? ????? ?? ??? ?? ????? ???? ???? ???? ? ???? ??? ?? ????? ???? ?????? ???? ??? ??? ?? ????? ?? ????. ???????? ????? ??? SRAM ???? ? ???? ? ????? ??? DRAM ????? ? ??? ?? ????? . ?? ???? ?? ????? ??? ? ?? ????? ??? SRAM ?????? ?????? ???? ???????? ( ??????? ?? Cache) ? ?? ????? ??? DRAM ???? ???? ????? RAM ?? ???????? ??????? ?? ????.

    32. Sources www.extremetech.com http://en.wikipedia.org/wiki/DRAM http://en.wikipedia.org/wiki/Dynamic_random_access_memory http://web.mit.edu/invent/iow/Dennard.html http://en.wikipedia.org/wiki/SDR_SDRAM http://www.fanooss.com http://forum.p30world.com/showthread.php?t=234 http://www.eetimes.com http://download.micron.com http://www.crucial.com/DDR/index.asp www.ece.umd.edu http://www.hpcaconf.org http://www.dramshopschool.com

    34. THE END

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