第15講半導(dǎo)體存儲(chǔ)器1

數(shù)字邏輯DigitalLogic青島理工大學(xué)廣義雙語(yǔ)教學(xué)課程課程網(wǎng)站：211.64.192.581半導(dǎo)體存儲(chǔ)器和可編程邏輯器件第7章MemoryandProgrammablelogicdeviceFlashmemoryisanon-volatilecomputerstoragetechnologythatcanbeelectricallyerasedandreprogrammed.Flashmemorycostsfarlessthanbyte-programmableEEPROMandthereforehasbecomethedominanttechnologywhereverasignificantamountofnon-volatile,solidstatestorageisneeded.（1）27.1半導(dǎo)體存儲(chǔ)器概述1、從存/取功能分①只讀存儲(chǔ)器

(ROM，Read-Only-Memory)②隨機(jī)讀/寫(xiě)存儲(chǔ)器(RAM，Random-Access-Memory)2、從工藝分①雙極型(BipolarTransistor)②MOS型(Metal-Oxide-Semiconductor)能存儲(chǔ)大量二值信息的器件?！飭卧獢?shù)龐大★輸入/輸出引腳數(shù)目有限3隨機(jī)(讀寫(xiě))存儲(chǔ)器RandomAccessMemory(RAM)只讀存儲(chǔ)器ReadOnlyMemory(ROM)PROM可編程序只讀存儲(chǔ)器掩膜ROMEPROM可擦除的可編程序只讀存儲(chǔ)器E2PROM電可擦除的可編程序只讀存儲(chǔ)器FlashMemory快閃存儲(chǔ)器（電可擦除）雙極型MOS型SRAMStaticRAM

DRAMSRAMDynamicRAM

半導(dǎo)體存儲(chǔ)器IC半導(dǎo)體RAM在斷電后數(shù)據(jù)會(huì)丟失，屬于易失性(Volatile)存儲(chǔ)器只讀存儲(chǔ)器屬于非易失性存儲(chǔ)器。4存儲(chǔ)器芯片內(nèi)部：地Y0A1址Y1

譯Y2A0碼Y3

器存儲(chǔ)單元00存儲(chǔ)單元01存儲(chǔ)單元10存儲(chǔ)單元11A0A1地址線條數(shù)K，可尋址2K單元半導(dǎo)體存儲(chǔ)器芯片MemoryChipAmemoryunitisacollectionofstoragecellstogetherwithassociatedcircuitsneededtotransferinformationinandoutofstorage.Thememorystoresbinaryinformationingroupsofbitscalledwords.存儲(chǔ)單元增加，地址線條數(shù)也迅速增加，地址譯碼器變復(fù)雜Eachwordinmemoryisassignedanidentificationnumber,calledanaddress,startingfrom0andcontinuingwith1,2,3,upto2k-1wherekisthenumberofaddresslines.5行地址譯碼列地址譯碼A0A1A3A2讀寫(xiě)控制

I/ORowAddressColumnAddress4×4存儲(chǔ)矩陣1110010011100100三態(tài)輸出

半導(dǎo)體RAM芯片內(nèi)部Theselectionofaspecificwordinsidethememoryisdonebyapplyingthek-bitbinaryaddresstotheaddresslines.Adecoderinsidethememoryacceptsthisaddressandopensthepathneededtoselectthebitsofthespecifiedword.ChipSelect6半導(dǎo)體存儲(chǔ)器的一般結(jié)構(gòu)形式輸入/出電路I/O輸入/出控制Awordinmemoryisanentityofbitsthatmoveinandoutofstorageasaunit.77.2.1掩模ROM7.2只讀存儲(chǔ)器

ROM掩模ROM基本結(jié)構(gòu)：8舉例：ABY&ABY≥19011111001001110110101000D0D1D2D3A0A1數(shù)據(jù)地址A0~An-1W0W(2n-1)D0Dm字線位線譯碼器存儲(chǔ)矩陣10存儲(chǔ)矩陣的每個(gè)交叉點(diǎn)是一個(gè)“存儲(chǔ)單元”，存儲(chǔ)單元中有器件存入“1”，無(wú)器件存入“0”兩個(gè)概念：存儲(chǔ)器的容量：“字?jǐn)?shù)×位數(shù)”M字×N位11掩模ROM的特點(diǎn)：出廠時(shí)已經(jīng)固定，不能更改，適合大量生產(chǎn)簡(jiǎn)單，便宜，非易失性當(dāng)只需要少量芯片的時(shí)候？127.2.2可編程只讀存儲(chǔ)器（PROM）總體結(jié)構(gòu)與掩模ROM一樣，但存儲(chǔ)單元不同寫(xiě)入時(shí)，要使用編程器（ProgrammableROM）137.5用存儲(chǔ)器設(shè)計(jì)組合邏輯電路1、基本原理從ROM的數(shù)據(jù)表可見(jiàn)：若以地址線為輸入變量， 則數(shù)據(jù)線即為一組關(guān)于地址變量的邏輯函數(shù)011111001001110110101000D0D1D2D3A0A1數(shù)據(jù)地址14用存儲(chǔ)器實(shí)現(xiàn)組合邏輯函數(shù)011111001001110110101000D0D1D2D3A0A1數(shù)據(jù)地址011111001001110110101000Y0Y1Y2Y3A0A1輸出輸入15變成最小項(xiàng)之和的形式用存儲(chǔ)器實(shí)現(xiàn)組合邏輯函數(shù)16用存儲(chǔ)器實(shí)現(xiàn)組合邏輯函數(shù)做數(shù)據(jù)表1111111110000000000000011000000000000000000000000000000000000001110111010011100101000000000000010000011110010111010011101111111117用存儲(chǔ)器實(shí)現(xiàn)組合邏輯函數(shù)1101111100110001010010011001101000100001000000000000000010000011010000000000000011001011000100001010011100000000011100110001111118只讀存儲(chǔ)器芯片外部：（符號(hào)，引腳）ROM（PROM，EPROM，E2PROM）芯片：常見(jiàn)：×8A0……A9

1024×4ROMD0D1D2D3練習(xí)：畫(huà)ROM芯片32K×8OutputEnable197.2.3可擦除的可編程只讀存儲(chǔ)器（EPROM）1、用紫外線擦除的EPROMUVEPROM(Ultra-VioletEPROM)10ErasablePROM2025V25VGND—111無(wú)110++++開(kāi)啟電壓加大++++++開(kāi)啟電壓5V5VGNDUVEPROM（Ultra-VioletEPROM）21UVEPROM不能在線編程，擦除不便EPROM擦除器222、電可擦除的可編程ROM（E2PROM）總體結(jié)構(gòu)與掩模ROM一樣，但存儲(chǔ)單元不同F(xiàn)loatingGateTunnelOxide23E2PROM(ElectronicErasablePROM)選通管能在線編程，按字擦除/改寫(xiě)247.2.4快閃存儲(chǔ)器（FlashMemory）為提高集成度，省去選通管T2,改用疊柵MOS管（類似SIMOS管）Flashmemorystoresinformationinanarrayofmemorycellsmadefromfloating-gatetransistors.Ontopisthecontrolgate(CG),asinotherMOStransistors,butbelowthisthereisafloatinggate(FG)insulatedallaroundbyanoxidelayer.BecausetheFGiselectricallyisolatedbyitsinsulatinglayer,anyelectronsplacedonitaretrappedthereand,undernormalconditions,willnotdischargeformanyyears.25快閃存儲(chǔ)器（FlashMemory）寫(xiě)入原理與EPROM相同。擦除利用隧道效應(yīng)。26各種PROM、EPROM、EEPROM、FlashMemory在讀出時(shí)的速度與RAM基本相同。

EEPROM和FlashMemory雖然可以在線擦除、改寫(xiě)，但是寫(xiě)的速度很慢，所以不能當(dāng)RAM用。

PROM和EPROM必須用編程器才能寫(xiě)入。

EPROM和EEPROM的價(jià)格高。

FlashMemory價(jià)格低，集成度高。

EEPROM可以一個(gè)字一個(gè)字的改寫(xiě)。

FlashMemory只能整片（或芯片中的一個(gè)分區(qū)）擦除、改寫(xiě)。Flashmemoryisaspecifictype