Department of ElectronicsAdvanced Information Storage13Atsufumi Hirohata16:00 14/November/2013 Thursday (V 120)

Quick Review over the Last LectureDRAM :Data stored in a capacitor. Electric charge needs to be refreshed. DRAM requires large power consumption.Read-out operation of 1C1T :1 V + V = 2 V2 V = 1 V + V3.6 VON1-data :1 V V = 0 V0 V = 1 V V3.6 VON0-data :* http://www.wikipedia.org/;

* http://users.cis.fiu.edu/~prabakar/cda4101/Common/notes/lecture09.htmlRefresh operation of 1C1T :

13 Static Random Access MemoryVolatile memory developmement6T-SRAM architectureRead / write operation1T-SRAMVarious ROMs

Memory Types* http://www.semiconductorjapan.net/serial/lesson/12.htmlRewritableRead onlyRead majority(Writable)VolatileNon-volatileNon-volatileNon-volatileDynamicStaticStaticStaticStaticDRAMSRAMMRAMFeRAMPRAMPROMMask ROMFlashEPROM

Manchester Automatic Digital MachineIn 1949, Frederic C. Williams and Tom Kilburn developed Manchester Mark 1 :* http://www.computer50.org/mark1/;** http://www.wikipedia.org/One of the earliest stored-programme computers

Williams-Kilburn TubeCathode-ray tube to store data :* http://www.wikipedia.org/Utilise a minor change of electron charges at a fluorescent screen when an electron hit it.

Delay Line MemoryIn 1947, John P. Eckart invented a mercury delay line memory :* http://www.wikipedia.org/Utilise an ultrasonic wave generated by a transducer to store a data.

Selectron TubeIn 1953, Jan A. Rajchman (RCA) invented a selectron tube :* http://www.ieeeghn.org/wiki/index.php/Jan_Rajchman;** http://www.wikipedia.org/An array of cathode-ray tubes is used to store data electrostatically.

Static Random Access Memory (SRAM)* http://www.wikipedia.org/Static random access memory (SRAM) :No need to dynamically refresh data. Even so, the data is lost once the power is off.Flip flop is used to store data. Low power consumption

6T-SRAM Read OperationA standard SRAM cell :* http://allthingsvlsi.wordpress.com/tag/6t-sram-operation/

6T-SRAM Write OperationWrite operation :* http://allthingsvlsi.wordpress.com/tag/6t-sram-operation/

1T-SRAMPseudo SRAM developed by MoSys :* http://www.wikipedia.org/; < 1/3 area< 1/2 power consumptionEasy to be embededSimple interfaceSimilar to SRAM performanceLower latency as compared with DRAMHigh fidelity (< 1 FIT / Mbit, FIT : failure in time of 10 9 hours)By comparing with the conventional 6T-SRAM,** http://www.mosys.com/high-density-memory.php

Advantages of 1T-SRAMComparison between 1T-SRAM, embedded SRAM (eSRAM) and 6T-SRAM :* http://media.corporate-ir.net/media_files/nsd/mosy/presentations/corp_pres_1103/sld012.htm

Mask ROMRead-only memory made by a photo-mask :* http://www.smspower.org/Development/MaskROMsCheapSimple structureIdeal for integrationInitial mask fabrication costLead time for mask fabricationNo design change without mask replacement

Programmable ROM (PROM)PROM bipolar cell :* http://www.electronics.dit.ie/staff/tscarff/memory/rom.htm

PROM ArchitecturePROM architecture :* http://www.electronics.dit.ie/staff/tscarff/memory/rom.htm

Erasable PROMUV-light can erase stored data :* http://www.electronics.dit.ie/staff/tscarff/memory/rom.htm* http://www.wikipedia.org/;

Electrically EPROM (EEPROM)In 1978, George Perlegos (Intel) developed electrical erasing mechanism :* http://www.answers.com/topic/eepromSimilar to flash memoryIndividual bits are erasable.Rewritable by simply writing a new dataRewritability > 100k timesSmall capacity (~ a few 10 bytes)More complicated architecture as compared with flash memoryHigher cost for fabrication as compared with flash memory

EEPROM UsagesEEPROM is used in various applications :* http://www.sanyosemi.com/en/memory/topics/serial-eeprom.php

Connections between the ComponentsConnections between CPU, in/outputs and storages :* http://testbench.in/introduction_to_pci_express.html;

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