is42s16400integrated silicon solution, inc. — 3 rev. d 01/30/08 is42s16400 pin functions symbol...

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Integrated Silicon Solution, Inc. — www.issi.com 1 Rev. D 01/3008 Copyright © 2006 Integrated Silicon Solution, Inc. All rights reserved. ISSI reserves the right to make changes to this specification and its products at any time without notice. ISSI assumes no liability arising out of the application or use of any information, products or services described herein. Customers are advised to obtain the latest version of this device specification before relying on any published information and before placing orders for products. IS42S16400 FEATURES Clock frequency: 166, 143 MHz Fully synchronous; all signals referenced to a positive clock edge Internal bank for hiding row access/precharge Single 3.3V power supply LVTTL interface Programmable burst length – (1, 2, 4, 8, full page) Programmable burst sequence: Sequential/Interleave Self refresh modes 4096 refresh cycles every 64 ms Random column address every clock cycle Programmable CAS latency (2, 3 clocks) Burst read/write and burst read/single write operations capability Burst termination by burst stop and precharge command Byte controlled by LDQM and UDQM Package: 400-mil 54-pin TSOP II Lead-free package is available Available in Industrial Temperature Power Down and Deep Power Down Mode Partial Array Self Refresh Temperature Compensated Self Refresh Output Driver Strength Selection (Please con- tact Product Manager for mobile function detail) OVERVIEW ISSI's 64Mb Synchronous DRAM IS42S16400 is organized as 1,048,576 bits x 16-bit x 4-bank for improved performance. The synchronous DRAMs achieve high-speed data transfer using pipeline architecture. All inputs and outputs signals refer to the rising edge of the clock input. 1 Meg Bits x 16 Bits x 4 Banks (64-MBIT) SYNCHRONOUS DYNAMIC RAM JANUARY 2008 PIN CONFIGURATIONS 54-Pin TSOP (Type II) VDD DQ0 VDDQ DQ1 DQ2 GNDQ DQ3 DQ4 VDDQ DQ5 DQ6 GNDQ DQ7 VDD LDQM WE CAS RAS CS BA0 BA1 A10 A0 A1 A2 A3 VDD 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 GND DQ15 GNDQ DQ14 DQ13 VDDQ DQ12 DQ11 GNDQ DQ10 DQ9 VDDQ DQ8 GND NC UDQM CLK CKE NC A11 A9 A8 A7 A6 A5 A4 GND PIN DESCRIPTIONS A0-A11 Address Input BA0, BA1 Bank Select Address DQ0 to DQ15 Data I/O CLK System Clock Input CKE Clock Enable CS Chip Select RAS Row Address Strobe Command CAS Column Address Strobe Command WE Write Enable LDQM Lower Bye, Input/Output Mask UDQM Upper Bye, Input/Output Mask VDD Power GND Ground VDDQ Power Supply for DQ Pin GNDQ Ground for DQ Pin NC No Connection

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  • Integrated Silicon Solution, Inc. — www.issi.com 1Rev. D01/3008

    Copyright © 2006 Integrated Silicon Solution, Inc. All rights reserved. ISSI reserves the right to make changes to this specification and its products at any time without notice. ISSI assumes no liability arising out of the application or use of any information, products or services described herein. Customers are advised to obtain the latest version of this device specification before relying on any published information and before placing orders for products.

    IS42S16400

    FEATURES• Clock frequency: 166, 143 MHz

    • Fullysynchronous;allsignalsreferencedtoapositive clock edge

    • Internalbankforhidingrowaccess/precharge

    • Single3.3Vpowersupply

    • LVTTLinterface

    • Programmableburstlength – (1, 2, 4, 8, full page)

    • Programmableburstsequence: Sequential/Interleave

    • Selfrefreshmodes

    • 4096refreshcyclesevery64ms

    • Randomcolumnaddresseveryclockcycle

    • ProgrammableCAS latency (2, 3 clocks)

    • Burstread/writeandburstread/singlewrite operations capability

    • Burstterminationbyburststopandprechargecommand

    • BytecontrolledbyLDQMandUDQM

    • Package:400-mil54-pinTSOPII

    • Lead-freepackageisavailable

    • AvailableinIndustrialTemperature

    • PowerDownandDeepPowerDownMode

    • PartialArraySelfRefresh

    • TemperatureCompensatedSelfRefresh

    • OutputDriverStrengthSelection(Pleasecon-tactProductManagerformobilefunctiondetail)

    OVERVIEWISSI's64MbSynchronousDRAMIS42S16400isorganizedas 1,048,576 bits x 16-bit x 4-bank for improved performance. ThesynchronousDRAMsachievehigh-speeddatatransferusing pipeline architecture. All inputs and outputs signals refer to the rising edge of the clock input.

    1 Meg Bits x 16 Bits x 4 Banks (64-MBIT) SYNCHRONOUS DYNAMIC RAM JANUARY 2008

    PIN CONFIGURATIONS54-Pin TSOP (Type II)

    VDD

    DQ0

    VDDQ

    DQ1

    DQ2

    GNDQ

    DQ3

    DQ4

    VDDQ

    DQ5

    DQ6

    GNDQ

    DQ7

    VDD

    LDQM

    WE

    CAS

    RAS

    CS

    BA0

    BA1

    A10

    A0

    A1

    A2

    A3

    VDD

    1

    2

    3

    4

    5

    6

    7

    8

    9

    10

    11

    12

    13

    14

    15

    16

    17

    18

    19

    20

    21

    22

    23

    24

    25

    26

    27

    54

    53

    52

    51

    50

    49

    48

    47

    46

    45

    44

    43

    42

    41

    40

    39

    38

    37

    36

    35

    34

    33

    32

    31

    30

    29

    28

    GND

    DQ15

    GNDQ

    DQ14

    DQ13

    VDDQ

    DQ12

    DQ11

    GNDQ

    DQ10

    DQ9

    VDDQ

    DQ8

    GND

    NC

    UDQM

    CLK

    CKE

    NC

    A11

    A9

    A8

    A7

    A6

    A5

    A4

    GND

    PIN DESCRIPTIONSA0-A11 Address Input

    BA0,BA1 BankSelectAddress

    DQ0toDQ15 DataI/O

    CLK SystemClockInput

    CKE ClockEnable

    CS Chip Select

    RAS RowAddressStrobeCommand

    CAS Column Address Strobe Command

    WE WriteEnable

    LDQM LowerBye,Input/OutputMask

    UDQM UpperBye,Input/OutputMask

    VDD Power

    GND Ground

    VDDq PowerSupplyforDQPin

    GNDq GroundforDQPin

    NC No Connection

  • 2 Integrated Silicon Solution, Inc. — www.issi.com Rev. D

    01/30/08

    IS42S16400

    GENERAL DESCRIPTIONThe 64Mb SDRAM is a high speed CMOS, dynamicrandom-access memory designed to operate in 3.3Vmemory systems containing 67,108,864 bits. Internally configured as a quad-bank DRAM with a synchronousinterface.Each16,777,216-bitbankisorganizedas4,096rows by 256 columns by 16 bits.

    The64MbSDRAMincludesanAUTOREFRESHMODE,and a power-saving, power-down mode. All signals are registeredonthepositiveedgeoftheclocksignal,CLK.AllinputsandoutputsareLVTTLcompatible.

    The64MbSDRAMhastheabilitytosynchronouslyburstdata at a high data rate with automatic column-address generation, the ability to interleave between internal banks to hide precharge time and the capability to randomly change column addresses on each clock cycle during burst access.

    A self-timed row precharge initiated at the end of the burst sequenceisavailablewiththeAUTOPRECHARGEfunctionenabled. Precharge one bank while accessing one of the

    other three banks will hide the precharge cycles and provide seamless, high-speed, random-access operation.

    SDRAM read and write accesses are burst oriented starting at a selected location and continuing for a programmed number of locations in a programmed sequence. Theregistration of an ACTIVE command begins accesses,followedbyaREADorWRITEcommand.TheACTIVEcommand in conjunction with address bits registered are usedtoselect thebankandrowtobeaccessed(BA0,BA1selectthebank;A0-A11selecttherow).TheREADor WRITE commands in conjunction with address bitsregistered are used to select the starting column location for the burst access.

    ProgrammableREADorWRITEburstlengthsconsistof1, 2, 4 and 8 locations, or full page, with a burst terminate option.

    CLKCKECSRASCASWEA10

    A9A8A7A6A5A4A3A2A1A0

    BA0BA1

    A11

    COMMANDDECODER

    &CLOCK

    GENERATOR MODEREGISTER

    REFRESHCONTROLLER

    REFRESHCOUNTER

    SELF

    REFRESH

    CONTROLLER

    ROWADDRESS

    LATCH MU

    LTIP

    LEX

    ER

    COLUMNADDRESS LATCH

    BURST COUNTER

    COLUMNADDRESS BUFFER

    COLUMN DECODER

    DATA INBUFFER

    DATA OUTBUFFER

    DQM

    DQ 0-15

    VDD/VDDQ

    GND/GNDQ

    12

    12

    8

    12

    12

    8

    16

    16 16

    16

    256K(x 16)

    4096

    4096

    4096

    RO

    W D

    EC

    OD

    ER 4096

    MEMORY CELLARRAY

    BANK 0

    SENSE AMP I/O GATE

    BANK CONTROL LOGIC

    ROWADDRESSBUFFER

    FUNCTIONAL BLOCK DIAGRAM

  • Integrated Silicon Solution, Inc. — www.issi.com 3Rev. D01/30/08

    IS42S16400

    PIN FUNCTIONS Symbol TSOP Pin No. Type Function (In Detail)

    A0-A11 23to26 InputPin AddressInputs:A0-A11aresampledduringtheACTIVE

    29to34 command(row-addressA0-A11)andREAD/WRITEcommand(A0-A7

    22, 35 with A10 defining auto precharge) to select one location out of the memory array intherespectivebank.A10issampledduringaPRECHARGEcommandtodeter-mine if all banks are to be precharged (A10 HIGH) or bank selected by BA0,BA1(LOW).Theaddressinputsalsoprovidetheop-codeduringaLOADMODEREGISTERcommand.

    BA0,BA1 20,21 InputPin BankSelectAddress:BA0andBA1defineswhichbanktheACTIVE,READ,WRITEorPRECHARGEcommandisbeingapplied.

    CAS 17 InputPin CAS, in conjunction with the RAS and WE, forms the device command. See the "CommandTruthTable"fordetailsondevicecommands.

    CKE 37 InputPin TheCKEinputdetermineswhethertheCLKinputisenabled.ThenextrisingedgeoftheCLKsignalwillbevalidwhenisCKEHIGHandinvalidwhenLOW.WhenCKEisLOW,thedevicewillbeineitherpower-downmode,clocksuspendmode,orselfrefresh mode. CKEisan asynchronous input.

    CLK 38 InputPin CLKisthemasterclockinputforthisdevice.ExceptforCKE,allinputstothisdeviceare acquired in synchronization with the rising edge of this pin.

    CS 19 InputPin TheCS input determines whether command input is enabled within the device. Command input is enabled when CSisLOW,anddisabledwithCSisHIGH.Thedevice remains in the previous state when CS is HIGH.

    DQ0to 2,4,5,7,8,10, DQPin DQ0toDQ15areI/Opins.I/Othroughthesepinscanbecontrolledinbyteunits

    DQ15 11,13, 42, 44, 45, usingtheLDQMandUDQMpins.

    47, 48, 50, 51, 53

    LDQM, 15,39 InputPin LDQMandUDQMcontrolthelowerandupperbytesoftheI/Obuffers.Inread

    UDQM mode,LDQMandUDQMcontroltheoutputbuffer.WhenLDQMorUDQMisLOW,thecorrespondingbufferbyteisenabled,andwhenHIGH,disabled.TheoutputsgototheHIGHimpedancestatewhenLDQM/UDQMisHIGH.Thisfunctioncor-responds to OEinconventionalDRAMs.Inwritemode,LDQMandUDQMcontroltheinputbuffer.WhenLDQMorUDQMisLOW,thecorrespondingbufferbyteisen-abled,anddatacanbewrittentothedevice.WhenLDQMorUDQMisHIGH,inputdata is masked and cannot be written to the device.

    RAS 18 InputPin RAS, in conjunction with CAS and WE, forms the device command. See the "Com-mandTruthTable"itemfordetailsondevicecommands.

    WE 16 InputPin WE, in conjunction with RAS and CAS, forms the device command. See the "Com-mandTruthTable"itemfordetailsondevicecommands.

    VDDq 3,9,43,49 PowerSupplyPin VDDq is the output buffer power supply.

    VDD 1,14,27 PowerSupplyPin VDD is the device internal power supply.

    GNDq 6,12,46,52 PowerSupplyPin GNDq is the output buffer ground.

    GND 28,41,54 PowerSupplyPin GND is the device internal ground.

  • 4 Integrated Silicon Solution, Inc. — www.issi.com Rev. D

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    IS42S16400

    FUNCTION (InDetail)A0-A11areaddressinputssampledduringtheACTIVE(row-address A0-A11)andREAD/WRITEcommand(A0-A7 withA10definingautoPRECHARGE). A10 is sampled during aPRECHARGEcommandtodetermineifallbanksaretobePRECHARGED(A10 HIGH)orbankselectedbyBA0,BA1(LOW).Theaddressinputsalsoprovidetheop-codeduringaLOADMODEREGISTERcommand.

    BankSelectAddress(BA0andBA1) defines which bank theACTIVE,READ,WRITEorPRECHARGEcommandis being applied.

    CAS, in conjunction with the RAS and WE, forms the device command.Seethe“CommandTruthTable”fordetailsondevice commands.

    TheCKEinputdetermineswhethertheCLKinputisen-abled.ThenextrisingedgeoftheCLKsignalwillbevalidwhenisCKEHIGHandinvalidwhenLOW.WhenCKEisLOW,thedevicewillbeineitherpower-downmode,CLOCKSUSPENDmode,orSELF-REFRESHmode.CKEisanasynchronous input.

    CLKisthemasterclockinputforthisdevice.ExceptforCKE,allinputstothisdeviceareacquiredinsynchroniza-tion with the rising edge of this pin.

    TheCS input determines whether command input is en-abled within the device. Command input is enabled when CS isLOW,anddisabledwithCS isHIGH.Thedeviceremains in the previous state when CS isHIGH.DQ0toDQ15areDQpins.DQthroughthesepinscanbecontrolledinbyteunitsusingtheLDQMandUDQMpins.

    LDQMandUDQMcontrolthelowerandupperbytesoftheDQbuffers.Inreadmode,LDQMandUDQMcontrolthe output buffer.When LDQM or UDQM is LOW, thecorresponding buffer byte is enabled, and when HIGH, disabled.TheoutputsgototheHIGHImpedanceStatewhenLDQM/UDQMisHIGH.Thisfunctioncorrespondsto OE inconventionalDRAMs.Inwritemode,LDQMandUDQMcontroltheinputbuffer.WhenLDQMorUDQMisLOW,thecorrespondingbufferbyteisenabled,anddatacanbewritten to thedevice.WhenLDQMorUDQMisHIGH, input data is masked and cannot be written to the device.

    RAS, in conjunction with CAS and WE , forms the device command.Seethe“CommandTruthTable”itemfordetailson device commands.

    WE , in conjunction with RAS and CAS , forms the device command.Seethe“CommandTruthTable”itemfordetailson device commands.

    VDDq is the output buffer power supply.

    VDD is the device internal power supply.

    GNDq is the output buffer ground.

    GNDisthedeviceinternalground.

    READTheREADcommandselectsthebankfromBA0,BA1inputsand starts a burst read access to an active row. Inputs A0-A7 provides the starting column location. When A10 is HIGH,thiscommandfunctionsasanAUTOPRECHARGEcommand. When the auto precharge is selected, the row beingaccessedwillbeprechargedattheendoftheREADburst.TherowwillremainopenforsubsequentaccesseswhenAUTOPRECHARGE isnot selected. DQ’s readdataissubjecttothelogiclevelontheDQMinputstwoclocksearlier.WhenagivenDQMsignalwasregisteredHIGH,thecorrespondingDQ’swillbeHigh-Ztwoclockslater.DQ’swillprovidevaliddatawhentheDQMsignalwasregisteredLOW.

    WRITEA burst write access to an active row is initiated with the WRITE command. BA0, BA1 inputs selects the bank,and the starting column location is provided by inputs A0-A7.Whether or notAUTO-PRECHARGE is used isdetermined by A10.

    TherowbeingaccessedwillbeprechargedattheendoftheWRITEburst, ifAUTOPRECHARGE isselected. IfAUTOPRECHARGEisnotselected,therowwillremainopen for subsequent accesses.

    A memory array is written with corresponding input data onDQ’sandDQMinputlogiclevelappearingatthesametime.DatawillbewrittentomemorywhenDQMsignalisLOW.WhenDQMisHIGH,thecorrespondingdatainputswillbeignored,andaWRITEwillnotbeexecutedtothatbyte/column location.

    PRECHARGEThePRECHARGEcommand isused todeactivate theopen row in a particular bank or the open row in all banks. BA0,BA1canbeusedtoselectwhichbankisprechargedor they are treated as “Don’t Care”. A10 determinedwhether one or all banks are precharged. After execut-ing this command, the next command for the selected banks(s) is executed after passage of the period tRP, which istheperiodrequiredforbankprecharging.Onceabankhas been precharged, it is in the idle state and must be activatedpriortoanyREADorWRITEcommandsbeingissued to that bank.

    AUTO PRECHARGETheAUTOPRECHARGEfunctionensuresthatthepre-charge is initiated at the earliest valid stage within a burst. Thisfunctionallowsforindividual-bankprechargewithoutrequiringanexplicitcommand.A10toenablestheAUTOPRECHARGEfunctioninconjunctionwithaspecificREADorWRITEcommand.ForeachindividualREADorWRITEcommand, auto precharge is either enabled or disabled.

  • Integrated Silicon Solution, Inc. — www.issi.com 5Rev. D01/30/08

    IS42S16400

    AUTOPRECHARGEdoesnotapplyexceptinfull-pageburst mode. Upon completion of the READ or WRITEburst, a precharge of the bank/row that is addressed is automatically performed.

    AUTO REFRESH COMMANDThiscommandexecutestheAUTOREFRESHoperation.Therowaddressandbanktoberefreshedareautomaticallygeneratedduringthisoperation. Thestipulatedperiod(trc) is required for a single refresh operation, and no other com-mandscanbeexecutedduringthisperiod. Thiscommandisexecutedatleast4096timesevery64ms.DuringanAUTOREFRESHcommand,addressbitsare“Don’tCare”.ThiscommandcorrespondstoCBRAuto-refresh.

    SELF REFRESHDuringtheSELFREFRESHoperation,therowaddresstobe refreshed, the bank, and the refresh interval are gen-eratedautomaticallyinternally.SELFREFRESHcanbeusedtoretaindataintheSDRAMwithoutexternalclocking,eveniftherestofthesystemispowereddown.TheSELFREFRESHoperationisstartedbydroppingtheCKEpinfromHIGHtoLOW.DuringtheSELFREFRESHoperationallotherinputstotheSDRAMbecome“Don’tCare”.Thedevice must remain in self refresh mode for a minimum period equal to tras or may remain in self refresh mode foranindefiniteperiodbeyondthat.TheSELF-REFRESHoperationcontinuesaslongastheCKEpinremainsLOWand there is no need for external control of any other pins. Thenextcommandcannotbeexecuteduntilthedeviceinternal recovery period (trc) has elapsed. Once CKEgoesHIGH,theNOPcommandmustbeissued(minimum of two clocks) to provide time for the completion of any internal refresh in progress. After the self-refresh, since it is impossible to determine the address of the last row to berefreshed,anAUTO-REFRESHshouldimmediatelybeperformed for all addresses.

    BURST TERMINATETheBURSTTERMINATEcommand forcibly terminatesthe burst read and write operations by truncating either fixed-length or full-page bursts and the most recently registeredREADorWRITEcommandpriortotheBURSTTERMINATE.

    COMMAND INHIBITCOMMANDINHIBITpreventsnewcommandsfrombeingexecuted.Operationsinprogressarenotaffected,apartfromwhethertheCLKsignalisenabled

    NO OPERATION When CSislow,theNOPcommandpreventsunwantedcommands from being registered during idle or wait states.

    LOAD MODE REGISTERDuringtheLOADMODEREGISTERcommandthemoderegisterisloadedfromA0-A11.Thiscommandcanonlybe issued when all banks are idle.

    ACTIVE COMMANDWhen the ACTIVE COMMAND is activated, BA0, BA1inputs selects a bank to be accessed, and the address inputsonA0-A11selectstherow.UntilaPRECHARGEcommand is issued to the bank, the row remains open for accesses.

  • 6 Integrated Silicon Solution, Inc. — www.issi.com Rev. D

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    IS42S16400

    TRUTH TABLE – COMMANDS AND DQM OPERATION(1)

    FUNCTION CS RAS CAS WE DQM ADDR DQs

    COMMANDINHIBIT(NOP) H X X X X X X

    NOOPERATION(NOP) L H H H X X X

    ACTIVE(Selectbankandactivaterow)(3) L L H H X Bank/Row X

    READ(Selectbank/column,startREADburst)(4) L H L H L/H(8) Bank/Col X

    WRITE(Selectbank/column,startWRITEburst)(4) L H L L L/H(8) Bank/Col Valid

    BURSTTERMINATE L H H L X X Active

    PRECHARGE(Deactivaterowinbankorbanks)(5) L L H L X Code X

    AUTOREFRESHorSELFREFRESH(6,7) L L L H X X X (Enterselfrefreshmode)

    LOADMODEREGISTER(2) L L L L X Op-Code X

    WriteEnable/OutputEnable(8) — — — — L — Active

    WriteInhibit/OutputHigh-Z(8) — — — — H — High-ZNOTES:1. CKEisHIGHforallcommandsexceptSELFREFRESH.2. A0-A11 define the op-code written to the mode register.3. A0-A11providerowaddress,andBA0,BA1determinewhichbankismadeactive.4. A0-A7(x16)providecolumnaddress;A10HIGHenablestheautoprechargefeature(nonpersistent),whileA10LOWdisables

    autoprecharge;BA0,BA1determinewhichbankisbeingreadfromorwrittento.5. A10LOW:BA0,BA1determinethebankbeingprecharged.A10HIGH:AllbanksprechargedandBA0,BA1are“Don’tCare.”6. AUTOREFRESHifCKEisHIGH,SELFREFRESHifCKEisLOW.7. Internalrefreshcountercontrolsrowaddressing;allinputsandI/Osare“Don’tCare”exceptforCKE.8. ActivatesordeactivatestheDQsduringWRITEs(zero-clockdelay)andREADs(two-clockdelay).

  • Integrated Silicon Solution, Inc. — www.issi.com 7Rev. D01/30/08

    IS42S16400

    TRUTH TABLE – CURRENT STATE BANK n, COMMAND TO BANK n (1-6)

    CURRENTSTATE COMMAND(ACTION) CS RAS CAS WE

    Any COMMANDINHIBIT(NOP/Continuepreviousoperation) H X X X

    NOOPERATION(NOP/Continuepreviousoperation) L H H H

    Idle ACTIVE(Selectandactivaterow) L L H H

    AUTOREFRESH(7) L L L H

    LOADMODEREGISTER(7) L L L L

    PRECHARGE(11) L L H L

    RowActive READ(SelectcolumnandstartREADburst)(10) L H L H

    WRITE(SelectcolumnandstartWRITEburst)(10) L H L L

    PRECHARGE(Deactivaterowinbankorbanks)(8) L L H L

    Read READ(SelectcolumnandstartnewREADburst)(10) L H L H

    (Auto WRITE(SelectcolumnandstartWRITEburst)(10) L H L L

    Precharge PRECHARGE(TruncateREADburst,startPRECHARGE)(8) L L H L

    Disabled) BURSTTERMINATE(9) L H H L

    Write READ(SelectcolumnandstartREADburst)(10) L H L H

    (Auto WRITE(SelectcolumnandstartnewWRITEburst)(10) L H L L

    Precharge PRECHARGE(TruncateWRITEburst,startPRECHARGE)(8) L L H L

    Disabled) BURSTTERMINATE(9) L H H LNOTE: 1.ThistableapplieswhenCKEn-1wasHIGHandCKEnisHIGH(seeTruthTable-CKE)andaftertxsr has been met (if the

    previous state was SELFREFRESH). 2.Thistableisbank-specific,exceptwherenoted;i.e.,thecurrentstateisforaspecificbankandthecommandsshownarethose

    allowedtobeissuedtothatbankwheninthatstate.Exceptionsarecoveredinthenotesbelow.

    TRUTH TABLE – CKE (1-4)

    CURRENT STATE COMMANDn ACTIONn CKEn-1 CKEn

    Power-Down X MaintainPower-Down L L

    SelfRefresh X MaintainSelfRefresh L L

    ClockSuspend X MaintainClockSuspend L L

    Power-Down(5) COMMANDINHIBITorNOP ExitPower-Down L H

    SelfRefresh(6) COMMANDINHIBITorNOP ExitSelfRefresh L H

    Clock Suspend(7) X ExitClockSuspend L H

    AllBanksIdle COMMANDINHIBITorNOP Power-DownEntry H L

    AllBanksIdle AUTOREFRESH SelfRefreshEntry H L

    ReadingorWriting VALID ClockSuspendEntry H L

    See TRUTH TABLE – CURRENT STATE BANK n, COMMAND TO BANK n H HNOTES: 1. CKEnisthelogicstateofCKEatclockedgen;CKEn-1 wasthestateofCKEatthepreviousclockedge.2. CurrentstateisthestateoftheSDRAMimmediatelypriortoclockedgen.3. COMMANDnisthecommandregisteredatclockedgen,andACTONnisaresultofCOMMANDn.4. All states and sequences not shown are illegal or reserved.5. Exitingpower-downatclockedgen will put the device in the all banks idle state in time for clock edge n+1 (provided that tcks is

    met).6. Exitingselfrefreshatclockedgen will put the device in all banks idle state once txsrismet.COMMANDINHIBITorNOP

    commands should be issued on clock edges occurring during the txsrperiod.AminimumoftwoNOPcommandsmustbesentduring txsr period.

    7. After exiting clock suspend at clock edge n, the device will resume operation and recognize the next command at clock edge n+1.

  • 8 Integrated Silicon Solution, Inc. — www.issi.com Rev. D

    01/30/08

    IS42S16400

    3. Current state definitions: Idle:Thebankhasbeenprecharged,andtrp has been met. RowActive:Arowinthebankhasbeenactivated,andtrcD has been met. No data bursts/accesses and no register

    accesses are in progress. Read:AREADbursthasbeeninitiated,withautoprechargedisabled,andhasnotyetterminatedorbeentermi-

    nated. Write:AWRITEbursthasbeeninitiated,withautoprechargedisabled,andhasnotyetterminatedorbeentermi-

    nated. 4.Thefollowingstatesmustnotbeinterruptedbyacommandissuedtothesamebank.COMMANDINHIBITorNOPcommands,

    or allowable commands to the other bank should be issued on any clock edge occurring during these states. Allowable com-mandstotheotherbankaredeterminedbyitscurrentstateandCURRENTSTATEBANKntruthtables.

    Precharging:StartswithregistrationofaPRECHARGEcommandandendswhentrpismet.Oncetrp is met, the bank will be in the idle state.

    RowActivating:StartswithregistrationofanACTIVEcommandandendswhentrcDismet.OncetrcD is met, the bank will be in the row active state.

    Readw/Auto PrechargeEnabled:StartswithregistrationofaREADcommandwithautoprechargeenabledandendswhentrp has been

    met.Oncetrp is met, the bank will be in the idle state. Write w/Auto PrechargeEnabled:StartswithregistrationofaWRITEcommandwithautoprechargeenabledandendswhentrp has been

    met.Oncetrp is met, the bank will be in the idle state. 5.Thefollowingstatesmustnotbeinterruptedbyanyexecutablecommand;COMMANDINHIBITorNOPcommandsmustbe

    applied on each positive clock edge during these states. Refreshing:StartswithregistrationofanAUTOREFRESHcommandandendswhentrcismet.Oncetrc is met, the

    SDRAMwillbeintheallbanksidlestate. Accessing Mode Register:StartswithregistrationofaLOADMODEREGISTERcommandandendswhentmrDhasbeenmet.Once

    tmrDismet,theSDRAMwillbeintheallbanksidlestate. PrechargingAll:StartswithregistrationofaPRECHARGEALLcommandandendswhentrpismet.Oncetrp is met, all

    banks will be in the idle state. 6. All states and sequences not shown are illegal or reserved. 7.Notbank-specific;requiresthatallbanksareidle. 8.Mayormaynotbebank-specific;ifallbanksaretobeprecharged,allmustbeinavalidstateforprecharging. 9.Notbank-specific;BURSTTERMINATEaffectsthemostrecentREADorWRITEburst,regardlessofbank.10.READsorWRITEslistedintheCommand(Action)columnincludeREADsorWRITEswithautoprechargeenabledand

    READsorWRITEswithautoprechargedisabled.11.DoesnotaffectthestateofthebankandactsasaNOPtothatbank.

  • Integrated Silicon Solution, Inc. — www.issi.com 9Rev. D01/30/08

    IS42S16400

    TRUTH TABLE – CURRENT STATE BANK n, COMMAND TO BANK m (1-6)

    CURRENTSTATE COMMAND(ACTION) CS RAS CAS WE

    Any COMMANDINHIBIT(NOP/Continuepreviousoperation) H X X X

    NOOPERATION(NOP/Continuepreviousoperation) L H H H

    Idle AnyCommandOtherwiseAllowedtoBankm X X X X

    Row ACTIVE(Selectandactivaterow) L L H H

    Activating, READ(SelectcolumnandstartREADburst)(7) L H L H

    Active,or WRITE(SelectcolumnandstartWRITEburst)(7) L H L L

    Precharging PRECHARGE L L H L

    Read ACTIVE(Selectandactivaterow) L L H H

    (Auto READ(SelectcolumnandstartnewREADburst)(7,10) L H L H

    Precharge WRITE(SelectcolumnandstartWRITEburst)(7,11) L H L L

    Disabled) PRECHARGE(9) L L H L

    Write ACTIVE(Selectandactivaterow) L L H H

    (Auto READ(SelectcolumnandstartREADburst)(7,12) L H L H

    Precharge WRITE(SelectcolumnandstartnewWRITEburst)(7,13) L H L L

    Disabled) PRECHARGE(9) L L H L

    Read ACTIVE(Selectandactivaterow) L L H H

    (WithAuto READ(SelectcolumnandstartnewREADburst)(7,8,14) L H L H

    Precharge) WRITE(SelectcolumnandstartWRITEburst)(7,8,15) L H L L

    PRECHARGE(9) L L H L

    Write ACTIVE(Selectandactivaterow) L L H H

    (WithAuto READ(SelectcolumnandstartREADburst)(7,8,16) L H L H

    Precharge) WRITE(SelectcolumnandstartnewWRITEburst)(7,8,17) L H L L

    PRECHARGE(9) L L H LNOTE: 1.ThistableapplieswhenCKEn-1wasHIGHandCKEnisHIGH(TruthTable-CKE)andaftertxsr has been met (if the previ-

    ous state was self refresh). 2.Thistabledescribesalternatebankoperation,exceptwherenoted;i.e.,thecurrentstateisforbankn and the commands

    shown are those allowed to be issued to bank m (assuming that bank m is in such a state that the given command is allowable).Excep-tions are covered in the notes below.

    3. Current state definitions: Idle:Thebankhasbeenprecharged,andtrp has been met. RowActive:Arowinthebankhasbeenactivated,andtrcD has been met. No data bursts/accesses and no register

    accesses are in progress. Read:AREADbursthasbeeninitiated,withautoprechargedisabled,andhasnotyetterminatedorbeentermi-

    nated. Write:AWRITEbursthasbeeninitiated,withautoprechargedisabled,andhasnotyetterminatedorbeentermi-

    nated. Readw/Auto PrechargeEnabled:StartswithregistrationofaREADcommandwithautoprechargeenabled,andendswhentrp has been

    met.Oncetrp is met, the bank will be in the idle state. Write w/Auto PrechargeEnabled:StartswithregistrationofaWRITEcommandwithautoprechargeenabled,andendswhentrp has been

    met.Oncetrp is met, the bank will be in the idle state. 4.AUTOREFRESH,SELFREFRESHandLOADMODEREGISTERcommandsmayonlybeissuedwhenallbanksareidle. 5.ABURSTTERMINATEcommandcannotbeissuedtoanotherbank;itappliestothebankrepresentedbythecurrentstate

    only. 6. All states and sequences not shown are illegal or reserved. 7.READsorWRITEstobankmlistedintheCommand(Action)columnincludeREADsorWRITEswithautoprechargeenabled

    andREADsorWRITEswithautoprechargedisabled.

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    IS42S16400

    8.CONCURRENTAUTOPRECHARGE:BanknwillinitiatetheAUTOPRECHARGEcommandwhenitsbursthasbeeninter-ruptedbybankm’sburst.

    9.Burstinbankncontinuesasinitiated.10.ForaREADwithoutautoprechargeinterruptedbyaREAD(withorwithoutautoprecharge),theREADtobankmwillinterrupt

    theREADonbankn,CASlatencylater(ConsecutiveREADBursts).11.ForaREADwithoutautoprechargeinterruptedbyaWRITE(withorwithoutautoprecharge),theWRITEtobankmwillinter-

    rupttheREADonbanknwhenregistered(READtoWRITE).DQMshouldbeusedoneclockpriortotheWRITEcommandtoprevent bus contention.

    12.ForaWRITEwithoutautoprechargeinterruptedbyaREAD(withorwithoutautoprecharge),theREADtobankmwillinterrupttheWRITEonbanknwhenregistered(WRITEtoREAD),withthedata-outappearingCASlatencylater.ThelastvalidWRITEtobanknwillbedata-inregisteredoneclockpriortotheREADtobankm.

    13.ForaWRITEwithoutautoprechargeinterruptedbyaWRITE(withorwithoutautoprecharge),theWRITEtobankmwillinter-rupttheWRITEonbanknwhenregistered(WRITEtoWRITE).ThelastvalidWRITEtobanknwillbedata-inregisteredoneclockpriortotheREADtobankm.

    14.ForaREADwithautoprechargeinterruptedbyaREAD(withorwithoutautoprecharge),theREADtobankmwillinterrupttheREADonbankn,CASlatencylater.ThePRECHARGEtobanknwillbeginwhentheREADtobankmisregistered(FigCAP1).

    15.ForaREADwithautoprechargeinterruptedbyaWRITE(withorwithoutautoprecharge),theWRITEtobankmwillinterrupttheREADonbanknwhenregistered.DQMshouldbeusedtwoclockspriortotheWRITEcommandtopreventbuscontention.ThePRECHARGEtobanknwillbeginwhentheWRITEtobankmisregistered(FigCAP2).

    16.ForaWRITEwithautoprechargeinterruptedbyaREAD(withorwithoutautoprecharge),theREADtobankmwillinterrupttheWRITEonbanknwhenregistered,withthedata-outappearingCASlatencylater.ThePRECHARGEtobanknwillbeginafter tWR is met, where twrbeginswhentheREADtobankmisregistered.ThelastvalidWRITEtobanknwillbedata-inregis-teredoneclockpriortotheREADtobankm(FigCAP3).

    17.ForaWRITEwithautoprechargeinterruptedbyaWRITE(withorwithoutautoprecharge),theWRITEtobankmwillinterrupttheWRITEonbanknwhenregistered.ThePRECHARGEtobanknwillbeginaftertwrismet,wheretWRbeginswhentheWRITEtobankmisregistered.ThelastvalidWRITEtobanknwillbedataregisteredoneclockpriortotheWRITEtobankm(FigCAP4).

  • Integrated Silicon Solution, Inc. — www.issi.com 11Rev. D01/30/08

    IS42S16400

    ABSOLUTE MAXIMUM RATINGS(1)

    Symbol Parameters Rating Unit

    VDD max MaximumSupplyVoltage –1.0to+4.6 V VDDq max MaximumSupplyVoltageforOutputBuffer –1.0to+4.6 V ViN InputVoltage –1.0toVDDq +0.5 V Vout OutputVoltage –1.0toVDDq +0.5 V PD max AllowablePowerDissipation 1 W Ics output Shorted Current 50 mA Topr operatingTemperature Com. 0to+70 °C Ind. -40to+85 °C Tstg StorageTemperature –65to+150 °C

    DC RECOMMENDED OPERATING CONDITIONS(2) (AtTa=0to+70°C)

    Symbol Parameter Min. Typ. Max. Unit

    VDD, VDDq SupplyVoltage 3.0 3.3 3.6 V Vih InputHighVoltage(3) 2.0 — VDD +0.3 V Vil InputLowVoltage(4) -0.3 — +0.8 V

    CAPACITANCE CHARACTERISTICS(1,2) (AtTa=0to+25°C,VDD=VDDq=3.3±0.3V,f=1MHz)

    Symbol Parameter Typ. Max. Unit

    CiN InputCapacitance:AddressandControl — 3.8 pF Cclk InputCapacitance:(CLK) — 3.5 pF CI/O DataInput/OutputCapacitance:I/O0-I/O15 — 6.5 pFNotes:1. StressgreaterthanthoselistedunderABSOLUTEMAXIMUMRATINGSmaycausepermanentdamagetothedevice.Thisisa

    stress rating only and functional operation of the device at these or any other conditions above those indicated in the operational sectionsofthisspecificationisnotimplied.Exposuretoabsolutemaximumratingconditionsforextendedperiodsmayaffectreliability.

    2. AllvoltagesarereferencedtoGND.3.Vih(max)=VDDq+2.0Vwithapulsewidth<3ns.4.Vil(min)=GND-2.0Vwithapulsewidth<3ns.

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    DC ELECTRICAL CHARACTERISTICS (RecommendedOperationConditionsunlessotherwisenoted.)

    Symbol Parameter Test Condition Speed Min. Max. Unit iil InputLeakageCurrent 0V≤ViN ≤VDD, with pins other than –5 5 µA thetestedpinat0V iol OutputLeakageCurrent Outputisdisabled,0V≤ Vout ≤VDD –5 5 µA Voh OutputHighVoltageLevel iout=–2mA 2.4 — V Vol OutputLowVoltageLevel iout=+2mA — 0.4 V

    icc1 OperatingCurrent(1,2) OneBankOperation,CASlatency=3Com. -6 — 95 mA BurstLength=1 Com. -7 — 85 mA trc ≥ trc (min.) Ind. -6 — 155 mA Iout = 0mA Ind. -7 — 145 icc2p PrechargeStandbyCurrent CKE≤ Vil (max) tck = 15ns Com. — — 2 mA Ind. — — 4 mA Icc2ps (InPower-DownMode) tck = ∞ Com. — — 2 mA Ind. — — 3 mA icc2N(3) PrechargeStandbyCurrent CKE≥ Vih (miN) tck = 15ns — — 20 mA Icc2Ns (InNonPower-DownMode) tck = ∞ Com. — — 15 mA Ind. — — 15 mA icc3p ActiveStandbyCurrent CKE≤ Vil (max) tck = 10ns Com. — — 7 mA Ind. — — 7 mA icc3ps (InPower-DownMode) tck = ∞ Com. — — 5 mA Ind. — — 5 mA icc3N(3) ActiveStandbyCurrent CKE≥ Vih (miN) tck = 15ns — — 30 mA Icc3Ns (InNonPower-DownMode) tck = ∞ Com. — — 25 mA Ind. — — 25 mA icc4 OperatingCurrent tck = tck (miN) CAS latency = 3 Com. -6 — 130 mA (InBurstMode)(1) Iout = 0mA Com. -7 — 100 mA BL=4;4banksactivated Ind. -6 — 140 mA Ind. -7 — 110 mA icc5 Auto-RefreshCurrent trc = trc (miN) CAS latency = 3 Com. -6 — 150 mA tclk = tclk (miN) Com. -7 — 130 mA Ind. -6 — 170 mA Ind. -7 — 150 mA icc6 Self-RefreshCurrent CKE≤0.2V — — 2 mANotes:1. Thesearethevaluesattheminimumcycletime.Sincethecurrentsaretransient,thesevaluesdecreaseasthecycletimein-

    creases.Alsonotethatabypasscapacitorofatleast0.01µFshouldbeinsertedbetweenVDDandGNDforeachmemorychipto suppress power supply voltage noise (voltage drops) due to these transient currents.

    2. Icc1 and Icc4dependontheoutputload.ThemaximumvaluesforIcc1 and Icc4 are obtained with the output open state.3. Input signal chnage once per 30ns.

  • Integrated Silicon Solution, Inc. — www.issi.com 13Rev. D01/30/08

    IS42S16400

    AC ELECTRICAL CHARACTERISTICS (1,2,3)

    -6 -7 Symbol Parameter Min. Max. Min. Max. Units tck3 ClockCycleTime CASLatency=3 6 — 7 — ns tck2 CASLatency=2 7.5 — 7.5 — ns

    tac3 AccessTimeFromCLK(4,6) CASLatency=3 — 5 — 5.4 ns tac2 CASLatency=2 — 6 — 6 ns

    tchi CLKHIGHLevelWidth 2 — 2.5 — ns

    tcl CLKLOWLevelWidth 2 — 2.5 — ns

    toh3 OutputDataHoldTime(6) CASLatency=3 2.5 — 2.7 — ns toh2 CAS Latency=2 2.5 — 3 — ns

    tlz OutputLOWImpedanceTime 0 — 0 — ns

    thz3 OutputHIGHImpedanceTime(5) CASLatency=3 — 5 — 5.4 ns thz2 CASLatency=2 — 6 — 6 ns

    tDs InputDataSetupTime 1.5 — 1.5 — ns

    tDh InputDataHoldTime 0.8 — 0.8 — ns

    tas AddressSetupTime 1.5 — 1.5 — ns

    tah AddressHoldTime 0.8 — 0.8 — ns

    tcks CKESetupTime 1.5 — 1.5 — ns

    tckh CKEHoldTime 0.8 — 0.8 — ns

    tcka CKEtoCLKRecoveryDelayTime 1CLK+3 — 1CLK+3 — ns

    tcs CommandSetupTime(CS, RAS, CAS, WE,DQM) 1.5 — 2.0 — ns

    tch CommandHoldTime(CS, RAS, CAS, WE,DQM) 0.8 — 1 — ns

    trc CommandPeriod(REFtoREF/ACTtoACT) 60 — 63 — ns

    tras CommandPeriod(ACTtoPRE) 42 100,000 42 100,000 ns

    trp CommandPeriod(PREtoACT) 18 — 20 — ns

    trcD ActiveCommandToRead/WriteCommandDelayTime 18 — 20 — ns

    trrD CommandPeriod(ACT[0]toACT[1]) 12 — 14 — ns

    tDpl or InputDataToPrecharge CASLatency=3 2CLK — 2CLK — ns twr CommandDelaytime CAS Latency=2 2CLK — 2CLK — ns

    tDal InputDataToActive/Refresh CASLatency=3 2CLK+trp — 2CLK+trp — ns CommandDelaytime(DuringAuto-Precharge) CAS Latency=2 2CLK+trp — 2CLK+trp — ns

    tt TransitionTime 1 10 1 10 ns

    tref RefreshCycleTime(4096) — 64 — 64 msNotes:1. Whenpowerisfirstapplied,memoryoperationshouldbestarted200µsafterVDDandVDDq reach their stipulated voltages. Also

    note that the power-on sequence must be executed before starting memory operation.2. measured with tt = 1 ns.3. Thereferencelevelis1.4Vwhenmeasuringinputsignaltiming.RiseandfalltimesaremeasuredbetweenVih (min.)andVil

    (max.).4. Accesstimeismeasuredat1.4Vwiththeloadshowninthefigurebelow.5. Thetimethz (max.)isdefinedasthetimerequiredfortheoutputvoltagetotransitionby±200mVfromVoh (min.)orVol (max.)

    when the output is in the high impedance state.6. If clock rising time is longer than 1ns, tr/2 - 0.5ns should be added to the parameter.

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    AC TEST CONDITIONS (Input/OutputReferenceLevel:1.4V)

    I/O

    50 Ω+1.5V

    50 pF

    Input Load Output Load

    2.0V

    1.4V

    0.8V

    CLK

    INPUT

    OUTPUT

    tCHI

    tCH

    tACtOH

    tCS

    tCKtCL

    2.0V

    1.4V

    1.4V 1.4V

    0.8V

    OPERATING FREQUENCY / LATENCY RELATIONSHIPS SYMBOL PARAMETER -6 -7 UNITS

    — ClockCycleTime 6 7 ns

    — OperatingFrequency 166 143 MHz

    tccD READ/WRITEcommandtoREAD/WRITEcommand 1 1 cycle

    tckeD CKEtoclockdisableorpower-downentrymode 1 1 cycle

    tpeD CKEtoclockenableorpower-downexitsetupmode 1 1 cycle

    tDqD DQMtoinputdatadelay 0 0 cycle

    tDqm DQMtodatamaskduringWRITEs 0 0 cycle

    tDqz DQMtodatahigh-impedanceduringREADs 2 2 cycle

    tDwD WRITEcommandtoinputdatadelay 0 0 cycle

    tDal Data-intoACTIVEcommand 5 5 cycle

    tDpl Data-intoPRECHARGEcommand 2 2 cycle

    tbDl Lastdata-intoburstSTOPcommand 1 1 cycle

    tcDl Lastdata-intonewREAD/WRITEcommand 1 1 cycle

    trDl Lastdata-intoPRECHARGEcommand 2 2 cycle

    tmrD LOADMODEREGISTERcommand 2 2 cycle toACTIVEorREFRESHcommand

    troh Data-outtohigh-impedancefrom CL=3 3 3 cycle PRECHARGEcommand CL=2 2 2 cycle

  • Integrated Silicon Solution, Inc. — www.issi.com 15Rev. D01/30/08

    IS42S16400

    FUNCTIONAL DESCRIPTIONThe64MbSDRAMs(1Megx16x4banks)arequad-bankDRAMswhichoperateat3.3Vandincludeasynchronousinterface (all signals are registered on the positive edge of theclocksignal,CLK).Eachofthe16,777,216-bitbanksisorganizedas4,096rowsby256columnsby16bits.

    ReadandwriteaccessestotheSDRAMareburstoriented;accesses start at a selected location and continue for a programmed number of locations in a programmed sequence. Accesses begin with the registration of an AC-TIVEcommandwhichisthenfollowedbyaREADorWRITEcommand.TheaddressbitsregisteredcoincidentwiththeACTIVEcommandareusedtoselectthebankandrowtobe accessed (BA0andBA1selectthebank,A0-A11selecttherow).Theaddressbits(A0-A7) registered coincident with the READorWRITEcommandareusedtoselectthestartingcolumn location for the burst access.

    Prior to normal operation, the SDRAM must be initial-ized.Thefollowingsectionsprovidedetailedinformationcovering device initialization, register definition, command descriptions and device operation.

    InitializationSDRAMs must be powered up and initialized in a predefined manner.

    The64MSDRAMisinitializedafterthepowerisappliedtoVDDandVDDq (simultaneously), and the clock is stable withDQMHighandCKEHigh.

    A 100µs delay is required prior to issuing any command other than a COMMANDINHIBIT or a NOP.TheCOMMANDINHIBITorNOPmaybeappliedduringthe100µsperiodandcontinue should at least through the end of the period.

    WithatleastoneCOMMANDINHIBITorNOPcommandhavingbeenapplied,aPRECHARGEcommandshouldbe applied once the 100µs delay has been satisfied. All banksmustbeprecharged.Thiswill leaveallbanksinan idle state, afterwhichatleasttwoAUTOREFRESH cycles must be performed. After the AUTOREFRESH cycles are complete, the SDRAM is then ready for mode registerprogramming.

    The mode register should be loaded prior to applyingany operational command because it will power up in an unknownstate.AftertheLoadModeRegistercommand,at least twoNOPcommandsmustbeassertedprior toany command.

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    REGISTER DEFINITION

    Mode RegisterThemode register isused todefine thespecificmodeofoperationof theSDRAM.Thisdefinition includestheselection of a burst length, a burst type, a CAS latency, an operating mode and a write burst mode, as shown in MODEREGISTERDEFINITION.

    ThemoderegisterisprogrammedviatheLOADMODEREGISTERcommandandwillretainthestoredinformationuntil it is programmed again or the device loses power.

    Mode register bits M0-M2 specify the burst length, M3 specifies the type of burst (sequential or interleaved), M4- M6 specify the CAS latency, M7 and M8 specify the operating mode,M9specifiestheWRITEburstmode,andM10andM11 are reserved for future use.

    Themode registermustbe loadedwhenallbanksareidle, and the controller must wait the specified time before initiatingthesubsequentoperation.Violatingeitheroftheserequirements will result in unspecified operation.

    MODE REGISTER DEFINITION

    Latency Mode

    M6 M5 M4 CAS Latency

    0 0 0 Reserved 0 0 1 Reserved 0 1 0 2 0 1 1 3 1 0 0 Reserved 1 0 1 Reserved 1 1 0 Reserved 1 1 1 Reserved

    1. To ensure compatibility with future devices,should program M11, M10 = "0, 0"

    Write Burst Mode

    M9 Mode

    0 Programmed Burst Length

    1 Single Location Access

    Operating Mode

    M8 M7 M6-M0 Mode

    0 0 Defined Standard Operation — — — All Other States Reserved

    Burst Type

    M3 Type

    0 Sequential 1 Interleaved

    Burst Length

    M2 M1 M0 M3=0 M3=1

    0 0 0 1 1 0 0 1 2 2 0 1 0 4 4 0 1 1 8 8 1 0 0 Reserved Reserved 1 0 1 Reserved Reserved 1 1 0 Reserved Reserved 1 1 1 Full Page Reserved

    Reserved

    Address Bus

    Mode Register (Mx)

    A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0

    (1)

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    BURST DEFINITION

    Burst Starting Column Order of Accesses Within a Burst

    Length Address Type = Sequential Type = Interleaved

    A0

    2 0 0-1 0-1

    1 1-0 1-0

    A1 A0

    0 0 0-1-2-3 0-1-2-3

    4 0 1 1-2-3-0 1-0-3-2

    1 0 2-3-0-1 2-3-0-1

    1 1 3-0-1-2 3-2-1-0

    A2 A1 A0

    0 0 0 0-1-2-3-4-5-6-7 0-1-2-3-4-5-6-7

    0 0 1 1-2-3-4-5-6-7-0 1-0-3-2-5-4-7-6

    0 1 0 2-3-4-5-6-7-0-1 2-3-0-1-6-7-4-5

    8 0 1 1 3-4-5-6-7-0-1-2 3-2-1-0-7-6-5-4

    1 0 0 4-5-6-7-0-1-2-3 4-5-6-7-0-1-2-3

    1 0 1 5-6-7-0-1-2-3-4 5-4-7-6-1-0-3-2

    1 1 0 6-7-0-1-2-3-4-5 6-7-4-5-2-3-0-1

    1 1 1 7-0-1-2-3-4-5-6 7-6-5-4-3-2-1-0

    Full n=A0-A7 Cn,Cn+1,Cn+2 NotSupported Page Cn+3,Cn+4... (y) (location 0-y) …Cn - 1, Cn…

    Burst LengthReadandwriteaccessestotheSDRAMareburstoriented,with the burst length being programmable, as shown in MODEREGISTERDEFINITION.Theburstlengthdeter-mines the maximum number of column locations that can beaccessedforagivenREADorWRITEcommand.Burstlengths of 1, 2, 4 or 8 locations are available for both the sequential and the interleaved burst types, and a full-page burst is available for the sequential type.The full-pageburstisusedinconjunctionwiththeBURSTTERMINATEcommand to generate arbitrary burst lengths.

    Reservedstatesshouldnotbeused,asunknownoperationor incompatibility with future versions may result.

    WhenaREADorWRITEcommandisissued,ablockofcolumns equal to the burst length is effectively selected. All accesses for that burst take place within this block, mean-

    ing that the burst will wrap within the block if a boundary isreached.TheblockisuniquelyselectedbyA1-A7(x16)whentheburstlengthissettotwo;byA2-A7(x16)whentheburstlengthissettofour;andbyA3-A7(x16)whentheburstlengthissettoeight.Theremaining(leastsignificant)address bit(s) is (are) used to select the starting location withintheblock.Full-pageburstswrapwithinthepageifthe boundary is reached.

    Burst TypeAccesses within a given burst may be programmed to be eithersequentialorinterleaved;thisisreferredtoastheburst type and is selected via bit M3.

    Theorderingofaccesseswithinaburstisdeterminedbythe burst length, the burst type and the starting column address,asshowninBURSTDEFINITIONtable.

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    DON'T CARE

    UNDEFINED

    CLK

    COMMAND

    DQ

    READ NOP NOP NOP

    CAS Latency - 3

    tAC

    tOH

    DOUT

    T0 T1 T2 T3 T4

    tLZ

    CLK

    COMMAND

    DQ

    READ NOP NOP

    CAS Latency - 2

    tAC

    tOH

    DOUT

    T0 T1 T2 T3

    tLZ

    CAS Latency

    CAS LatencyTheCAS latency is thedelay, inclockcycles,betweenthe registrationofaREADcommandandtheavailabilityofthefirstpieceofoutputdata.Thelatencycanbesettotwoorthree clocks.

    IfaREADcommandisregisteredatclockedgen,andthe latency is m clocks, the data will be available by clock edge n + m.TheDQswillstartdrivingasaresultoftheclock edge one cycle earlier (n + m - 1), and provided that the relevant access times are met, the data will be valid by clock edge n + m.Forexample,assumingthattheclockcycle time is such that all relevant access times are met, ifaREADcommandisregisteredatT0andthelatencyisprogrammedto twoclocks, theDQswillstartdrivingafterT1andthedatawillbevalidbyT2,asshowninCASLatencydiagrams.TheAllowable Operating Frequency table indicates the operating frequencies at which each CAS latency setting can be used.

    Reservedstatesshouldnotbeusedasunknownoperationor incompatibility with future versions may result.

    CAS LatencyAllowable Operating Frequency (MHz)

    Speed CAS Latency = 2 CAS Latency = 3

    6 133 166

    7 133 143

    Operating ModeThenormaloperatingmodeisselectedbysettingM7andM8tozero;theothercombinationsofvaluesforM7andM8arereservedforfutureuseand/ortestmodes.TheprogrammedburstlengthappliestobothREADandWRITEbursts.

    Testmodesandreservedstatesshouldnotbeusedbe-cause unknown operation or incompatibility with future versions may result.

    Write Burst ModeWhenM9=0,theburstlengthprogrammedviaM0-M2appliestobothREADandWRITEbursts;whenM9=1,theprogrammedburstlengthappliestoREADbursts,butwrite accesses are single-location (nonburst) accesses.

  • Integrated Silicon Solution, Inc. — www.issi.com 19Rev. D01/30/08

    IS42S16400

    CLK

    CKEHIGH - Z

    ROW ADDRESS

    BANK ADDRESS

    CS

    RAS

    CAS

    WE

    A0-A11

    BA0, BA1

    Activating Specific Row Within Specific Bank

    DON'T CARE

    CLK

    COMMAND ACTIVE NOP NOP

    tRCD

    T0 T1 T2 T3 T4

    READ orWRITE

    OPERATION

    BANK/ROW ACTIVATIONBeforeanyREADorWRITEcommandscanbe issuedtoabankwithintheSDRAM,arowinthatbankmustbe“opened.”ThisisaccomplishedviatheACTIVEcommand,which selects both the bank and the row to be activated (see ActivatingSpecificRowWithinSpecificBank).

    After opening a row (issuinganACTIVEcommand),aREADorWRITEcommandmaybeissuedtothatrow,subjecttothe trcD specification. Minimum trcD should be divided by the clock period and rounded up to the next whole number to determine the earliest clock edge after the ACTIVEcommandonwhichaREADorWRITEcommandcanbeentered.Forexample,atrcD specification of 20ns with a 125 MHz clock (8ns period) results in 2.5 clocks, rounded to3.Thisisreflectedinthefollowingexample,whichcov-ersanycasewhere2<[trcD (MIN)/tck] ≤3.(Thesameprocedure is used to convert other specification limits from time units to clock cycles).

    AsubsequentACTIVEcommandtoadifferentrowinthesame bank can only be issued after the previous active rowhasbeen“closed”(precharged).TheminimumtimeintervalbetweensuccessiveACTIVEcommands to thesame bank is defined by trc.

    AsubsequentACTIVEcommandtoanotherbankcanbeissued while the first bank is being accessed, which results inareductionoftotalrow-accessoverhead.TheminimumtimeintervalbetweensuccessiveACTIVEcommandstodifferent banks is defined by trrD.

    Example: Meeting tRCD (MIN) when 2 < [tRCD (min)/tCK] ≤ 3

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    IS42S16400

    CLK

    CKEHIGH-Z

    COLUMN ADDRESS

    AUTO PRECHARGE

    NO PRECHARGE

    CS

    RAS

    CAS

    WE

    A0-A7

    A10

    BA0, BA1 BANK ADDRESS

    A8, A9, A11

    READ COMMANDREADSREAD bursts are initiated with a READ command, asshownintheREADCOMMANDdiagram.

    ThestartingcolumnandbankaddressesareprovidedwiththeREADcommand,andautoprechargeiseitherenabledordisabled for that burst access. If auto precharge is enabled, the row being accessed is precharged at the completion of theburst.ForthegenericREADcommandsusedinthefol-lowing illustrations, auto precharge is disabled.

    DuringREADbursts,thevaliddata-outelementfromthestarting column address will be available following the CASlatencyaftertheREADcommand.Eachsubsequentdata-out element will be valid by the next positive clock edge.TheCASLatencydiagramshowsgeneral timing for each possible CAS latency setting.

    Uponcompletionofaburst,assumingnoothercommandshavebeeninitiated,theDQswillgoHigh-Z.Afull-pageburstwill continue until terminated. (At the end of the page, it will wrap to column 0 and continue.)

    DatafromanyREADburstmaybetruncatedwithasub-sequentREADcommand,anddatafromafixed-lengthREADburstmaybeimmediatelyfollowedbydatafromaREADcommand.Ineithercase,acontinuousflowofdatacanbemaintained.Thefirstdataelementfromthenewburst follows either the last element of a completed burst or the last desired data element of a longer burst which is being truncated.

    ThenewREADcommandshouldbeissuedx cycles before the clock edge at which the last desired data element is valid, where x equalstheCASlatencyminusone.ThisisshowninConsecutiveREADBurstsforCASlatenciesoftwoandthree;dataelementn +3iseitherthelastofaburstoffourorthelastdesiredofalongerburst.The64MbSDRAMusesapipelinedarchitectureandthereforedoesnot require the 2n rule associated with a prefetch architec-ture.AREADcommandcanbeinitiatedonanyclockcyclefollowingapreviousREADcommand.Full-speedrandomread accesses can be performed to the same bank, as showninRandomREADAccesses,oreachsubsequentREADmaybeperformedtoadifferentbank.

    DatafromanyREADburstmaybetruncatedwithasub-sequent WRITE command, and data from a fixed-lengthREADburstmaybeimmediatelyfollowedbydatafromaWRITEcommand(subjecttobusturnaroundlimitations).TheWRITEburstmaybeinitiatedontheclockedgeim-mediately following the last (or last desired) data element fromtheREADburst,providedthatI/Ocontentioncanbeavoided. In a given system design, there may be a pos-sibilitythatthedevicedrivingtheinputdatawillgoLow-ZbeforetheSDRAMDQsgoHigh-Z.Inthiscase,atleasta single-cycle delay should occur between the last read dataandtheWRITEcommand.

    TheDQMinputisusedtoavoidI/Ocontention,asshowninFiguresRW1andRW2.TheDQMsignalmustbeas-serted (HIGH)at least threeclocksprior to theWRITEcommand(DQMlatencyistwoclocksforoutputbuffers)tosuppressdata-out fromtheREAD.Once theWRITEcommandisregistered,theDQswillgoHigh-Z(orremainHigh-Z),regardlessofthestateoftheDQMsignal,providedtheDQMwasactiveontheclockjustpriortotheWRITEcommandthattruncatedtheREADcommand.Ifnot,thesecondWRITEwillbeaninvalidWRITE.Forexample,ifDQMwasLOWduringT4inFigureRW2,thentheWRITEsatT5andT7wouldbevalid,whiletheWRITEatT6wouldbe invalid.

    TheDQMsignalmustbede-assertedpriortotheWRITEcommand(DQMlatencyiszeroclocksforinputbuffers)to ensure that the written data is not masked.

    Afixed-lengthREADburstmaybefollowedby,ortruncatedwith, a PRECHARGE command to the same bank (provided that auto precharge was not activated), and a full-page burst maybetruncatedwithaPRECHARGEcommandtothesamebank.ThePRECHARGEcommandshouldbeissuedx cycles before the clock edge at which the last desired data element is valid, where x equals the CAS latency minusone.ThisisshownintheREADtoPRECHARGE

  • Integrated Silicon Solution, Inc. — www.issi.com 21Rev. D01/30/08

    IS42S16400

    DON'T CARE

    UNDEFINED

    CLK

    COMMAND

    DQ

    READ NOP NOP NOP

    CAS Latency - 3

    tAC

    tOH

    DOUT

    T0 T1 T2 T3 T4

    tLZ

    CLK

    COMMAND

    DQ

    READ NOP NOP

    CAS Latency - 2

    tAC

    tOH

    DOUT

    T0 T1 T2 T3

    tLZ

    CAS Latency

    diagramforeachpossibleCASlatency;dataelementn +3 is either the last of a burst of four or the last desired of alongerburst.FollowingthePRECHARGEcommand,asubsequent command to the same bank cannot be issued until trp is met. Note that part of the row precharge time is hidden during the access of the last data element(s).

    In the case of a fixed-length burst being executed to completion, a PRECHARGE command issued at theoptimum time (as described above) provides the same operation that would result from the same fixed-length burstwithautoprecharge.ThedisadvantageofthePRE-CHARGEcommandisthatitrequiresthatthecommandand address buses be available at the appropriate time to issuethecommand;theadvantageofthePRECHARGEcommand is that it can be used to truncate fixed-length or full-page bursts.

    Full-pageREADburstscanbetruncatedwiththeBURSTTERMINATE command, and fixed-length READ burstsmaybetruncatedwithaBURSTTERMINATEcommand,providedthatautoprechargewasnotactivated.TheBURSTTERMINATEcommandshouldbeissuedx cycles before the clock edge at which the last desired data element is valid, where x equalstheCASlatencyminusone.ThisisshownintheREADBurstTerminationdiagramforeachpossibleCASlatency;dataelementn +3isthelastdesireddata element of a longer burst.

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    IS42S16400

    DON'T CARE

    CLK

    COMMAND

    ADDRESS

    DQ

    T0 T1 T2 T3 T4 T5 T6

    READ NOP NOP NOP READ NOP NOP

    DOUT n DOUT n+1 DOUT n+2 DOUT n+3 DOUT b

    BANK,COL n

    BANK,COL b

    CAS Latency - 2

    x = 1 cycle

    DON'T CARE

    CLK

    COMMAND

    ADDRESS

    DQ

    T0 T1 T2 T3 T4 T5 T6 T7

    READ NOP NOP NOP READ NOP NOP NOP

    DOUT n DOUT n+1 DOUT n+2 DOUT n+3 DOUT b

    BANK,COL n

    BANK,COL b

    CAS Latency - 3

    x = 2 cycles

    Consecutive READ Bursts

  • Integrated Silicon Solution, Inc. — www.issi.com 23Rev. D01/30/08

    IS42S16400

    DON'T CARE

    CLK

    COMMAND

    ADDRESS

    DQ

    T0 T1 T2 T3 T4 T5

    READ READ READ READ NOP NOP

    DOUT n DOUT b DOUT m DOUT x

    BANK,COL n

    BANK,COL b

    CAS Latency - 2

    BANK,COL m

    BANK,COL x

    DON'T CARE

    CLK

    COMMAND

    ADDRESS

    DQ

    T0 T1 T2 T3 T4 T5 T6

    READ READ READ READ NOP NOP NOP

    DOUT n DOUT b DOUT m DOUT x

    BANK,COL n

    BANK,COL b

    CAS Latency - 3

    BANK,COL m

    BANK,COL x

    Random READ Accesses

  • 24 Integrated Silicon Solution, Inc. — www.issi.com Rev. D

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    IS42S16400

    DON'T CARE

    CLK

    DQM

    COMMAND

    ADDRESS

    DQ

    T0 T1 T2 T3 T4 T5

    READ NOP NOP NOP NOP WRITE

    BANK,COL n

    BANK,COL b

    DOUT n DIN b

    tDS

    tHZ

    CAS Latency - 3

    RW1 - READ to WRITE

    RW2 - READ to WRITE

    DON'T CARE

    CLK

    DQM

    COMMAND

    ADDRESS

    DQ

    T0 T1 T2 T3 T4 T5 T6

    READ NOP NOP NOP NOP NOP WRITE

    BANK,COL n

    DIN b

    tDS

    tHZ

    BANK,COL b

    CAS Latency - 2

    DOUT n DOUT n+1 DOUT n+2

  • Integrated Silicon Solution, Inc. — www.issi.com 25Rev. D01/30/08

    IS42S16400

    DON'T CARE

    CLK

    COMMAND

    ADDRESS

    DQ

    T0 T1 T2 T3 T4 T5 T6 T7

    READ NOP NOP NOP NOP NOP ACTIVE

    DOUT n DOUT n+1 DOUT n+2 DOUT n+3

    BANK a,COL n

    BANK a,ROW

    BANK(a or all)

    CAS Latency - 2

    x = 1 cycle

    tRP

    PRECHARGE

    DON'T CARE

    CLK

    COMMAND

    ADDRESS

    DQ

    T0 T1 T2 T3 T4 T5 T6 T7

    READ NOP NOP NOP NOP NOP ACTIVE

    DOUT n DOUT n+1 DOUT n+2 DOUT n+3

    BANK,COL n

    BANK,COL b

    CAS Latency - 3

    x = 2 cycles

    tRP

    BANK a,ROW

    PRECHARGE

    READ to PRECHARGE

  • 26 Integrated Silicon Solution, Inc. — www.issi.com Rev. D

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    IS42S16400

    DON'T CARE

    CLK

    COMMAND

    ADDRESS

    DQ

    T0 T1 T2 T3 T4 T5 T6

    READ NOP NOP NOP NOP NOP

    DOUT n DOUT n+1 DOUT n+2 DOUT n+3

    BANK a,COL n

    CAS Latency - 2

    x = 1 cycle

    BURSTTERMINATE

    DON'T CARE

    CLK

    COMMAND

    ADDRESS

    DQ

    T0 T1 T2 T3 T4 T5 T6 T7

    READ NOP NOP NOP NOP NOP NOP

    DOUT n DOUT n+1 DOUT n+2 DOUT n+3

    BANK,COL n

    CAS Latency - 3

    x = 2 cycles

    BURSTTERMINATE

    READ Burst Termination

  • Integrated Silicon Solution, Inc. — www.issi.com 27Rev. D01/30/08

    IS42S16400

    CLK

    CKEHIGH - Z

    COLUMN ADDRESS

    AUTO PRECHARGE

    BANK ADDRESS

    CS

    RAS

    CAS

    WE

    A0-A7

    A10

    BA0, BA1

    NO PRECHARGE

    A8, A9, A11

    WRITE Command

    ThestartingcolumnandbankaddressesareprovidedwiththeWRITEcommand,andautoprechargeiseitherenabledor disabled for that access. If auto precharge is enabled, the row being accessed is precharged at the completion of theburst.ForthegenericWRITEcommandsusedinthefollowing illustrations, auto precharge is disabled.

    DuringWRITEbursts,thefirstvaliddata-in element will be registered coincident with the WRITEcommand. Subsequent data elements will be registered on each successive posi-tiveclockedge.Uponcompletionofafixed-lengthburst,assuming no other commands have been initiated, the DQswillremainHigh-Zandanyadditionalinputdatawillbeignored(seeWRITEBurst).Afull-pageburstwillcon-tinue until terminated. (At the end of the page, it will wrap to column 0 and continue.)

    DataforanyWRITEburstmaybetruncatedwithasubse-quentWRITEcommand,anddataforafixed-lengthWRITEburstmaybe immediately followedbydata foraWRITEcommand.ThenewWRITEcommandcanbe issuedonanyclockfollowingthepreviousWRITEcommand,andthedata provided coincident with the new command applies to the new command.

    AnexampleisshowninWRITEtoWRITEdiagram.Datan +1iseitherthelastofaburstoftwoorthelastdesiredof a longer burst.The 64Mb SDRAM uses a pipelinedarchitecture and therefore does not require the 2n rule as-sociatedwithaprefetcharchitecture.AWRITEcommandcan be initiated on any clock cycle following a previous WRITEcommand.Full-speedrandomwriteaccesseswithina page can be performed to the same bank, as shown in RandomWRITECycles,oreachsubsequentWRITEmaybe performed to a different bank.

    DataforanyWRITEburstmaybetruncatedwithasubse-quentREADcommand,anddataforafixed-lengthWRITEburstmaybeimmediatelyfollowedbyasubsequentREADcommand.OncetheREADcommandisregistered,thedatainputswillbeignored,andWRITEswillnotbeex-ecuted.AnexampleisshowninWRITEtoREAD.Datan +1iseitherthelastofaburstoftwoorthelastdesiredof a longer burst.

    Data for a fixed-length WRITE burst may be followedby,or truncatedwith,aPRECHARGEcommandto thesame bank (provided that auto precharge was not acti-vated), anda full-pageWRITEburstmaybe truncatedwithaPRECHARGEcommand to thesamebank.ThePRECHARGEcommandshouldbeissuedtwr after the clock edge at which the last desired input data element isregistered.Theautoprechargemoderequiresatwr of at least one clock plus time, regardless of frequency. In addition,whentruncatingaWRITEburst,theDQMsignalmust be used to mask input data for the clock edge prior to,andtheclockedgecoincidentwith,thePRECHARGEcommand.AnexampleisshownintheWRITEtoPRE-CHARGEdiagram.Datan+1iseitherthelastofaburstoftwoorthelastdesiredofalongerburst.FollowingthePRECHARGEcommand,asubsequentcommandtothesame bank cannot be issued until trp is met.

    In the case of a fixed-length burst being executed to comple-tion,aPRECHARGEcommand issuedat theoptimumtime (as described above) provides the same operation that would result from the same fixed-length burst with auto precharge.ThedisadvantageofthePRECHARGE command is that it requires that the command and address buses be availableattheappropriatetimetoissuethecommand;theadvantageofthePRECHARGEcommandisthatitcanbeused to truncate fixed-length or full-page bursts.

    Fixed-lengthorfull-pageWRITEburstscanbetruncatedwiththeBURSTTERMINATEcommand.Whentruncat-ingaWRITEburst,theinputdataappliedcoincidentwiththeBURSTTERMINATEcommandwillbeignored.Thelastdatawritten(providedthatDQMisLOWatthattime)will be the input data applied one clock previous to the BURSTTERMINATEcommand.ThisisshowninWRITEBurstTermination,wheredatan is the last desired data element of a longer burst.

    WRITEsWRITEburstsareinitiatedwithaWRITEcommand,asshowninWRITECommanddiagram.

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    IS42S16400

    CLK

    COMMAND

    ADDRESS

    DQ

    T0 T1 T2 T3

    WRITE NOP NOP NOP

    DIN n DIN n+1

    BANK,COL n

    DON'T CARE

    CLK

    COMMAND

    ADDRESS

    DQ

    T0 T1 T2

    WRITE NOP WRITE

    DIN n DIN n+1 DIN b

    BANK,COL n

    BANK,COL b

    DON'T CARE

    WRITE Burst

    WRITE to WRITE

    CLK

    COMMAND

    ADDRESS

    DQ

    T0 T1 T2 T3

    WRITE WRITE WRITE WRITE

    DIN n DIN b DIN m DIN x

    BANK,COL n

    BANK,COL b

    BANK,COL m

    BANK,COL x

    Random WRITE Cycles

  • Integrated Silicon Solution, Inc. — www.issi.com 29Rev. D01/30/08

    IS42S16400

    DON'T CARE

    CLK

    COMMAND

    ADDRESS

    DQ

    T0 T1 T2 T3 T4 T5

    WRITE NOP READ NOP NOP NOP

    DIN n DIN n+1 DOUT b DOUT b+1

    BANK,COL n

    BANK,COL b

    CAS Latency - 2

    WRITE to READ

    WP1 - WRITE to PRECHARGE

    DON'T CARE

    CLK

    DQM

    COMMAND

    ADDRESS

    DQ

    T0 T1 T2 T3 T4 T5 T6

    WRITE NOP NOP ACTIVE NOP NOP

    BANK a,COL n

    BANK a,ROW

    BANK(a or all)

    tWR

    tRP

    PRECHARGE

    DIN n DIN n+1

    CAS Latency - 2

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    IS42S16400

    CLK

    COMMAND

    ADDRESS

    DQ

    T0 T1 T2

    WRITE

    DIN n (DATA)

    BANK,COL n

    DON'T CARE

    (ADDRESS)

    BURSTTERMINATE

    NEXTCOMMAND

    WRITE Burst Termination

    DON'T CARE

    CLK

    DQM

    COMMAND

    ADDRESS

    DQ

    T0 T1 T2 T3 T4 T5 T6

    WRITE NOP NOP NOP ACTIVE NOP

    BANK a,COL n

    BANK a,ROW

    BANK(a or all)

    tWR

    tRP

    PRECHARGE

    DIN n DIN n+1

    CAS Latency - 3

    WP2 - WRITE to PRECHARGE

  • Integrated Silicon Solution, Inc. — www.issi.com 31Rev. D01/30/08

    IS42S16400

    CLK

    CKEHIGH - Z

    ALL BANKS

    BANK SELECT

    BANK ADDRESS

    CS

    RAS

    CAS

    WE

    A0-A9, A11

    A10

    BA0, BA1

    DON'T CARE

    CLK

    CKE

    COMMAND NOP NOP ACTIVE

    ≥ tCKStCKS

    All banks idle

    Enter power-down mode Exit power-down mode

    tRCDtRAStRC

    Input buffers gated off

    PRECHARGE Command

    POWER-DOWN

    POWER-DOWNPower-downoccursifCKEisregisteredLOWcoincidentwithaNOPorCOMMANDINHIBITwhennoaccessesare in progress. If power-down occurs when all banks are idle,thismodeisreferredtoasprechargepower-down;if power-down occurs when there is a row active in either bank, this mode is referred to as active power-down. Entering power-down deactivates the input and outputbuffers,excludingCKE,formaximumpowersavingswhileinstandby.Thedevicemaynotremaininthepower-downstate longer than the refresh period (64ms) since no refresh operations are performed in this mode.

    Thepower-downstateisexitedbyregisteringaNOPorCOMMANDINHIBITandCKEHIGHatthedesiredclockedge (meeting tcks). See figure below.

    PRECHARGEThePRECHARGEcommand(seefigure)isusedtodeac-tivate the open row in a particular bank or the open row in allbanks.Thebank(s)willbeavailableforasubsequentrowaccess some specified time (trp)afterthePRECHARGEcommand is issued. Input A10 determines whether one or all banks are to be precharged, and in the case where only onebankistobeprecharged,inputsBA0,BA1selectthebank.Whenallbanksaretobeprecharged,inputsBA0,BA1aretreatedas“Don’tCare.”Onceabankhasbeenprecharged, it is in the idle state and must be activated priortoanyREADorWRITEcommandsbeingissuedtothat bank.

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    IS42S16400

    DON'T CARE

    CLK

    CKE

    COMMAND

    ADDRESS

    DQ

    T0 T1 T2 T3 T4 T5

    NOP WRITE NOP NOP

    BANK a,COL n

    DIN n DIN n+1 DIN n+2

    INTERNALCLOCK

    DON'T CARE

    CLK

    CKE

    COMMAND

    ADDRESS

    DQ

    T0 T1 T2 T3 T4 T5 T6

    READ NOP NOP NOP NOP NOP

    BANK a,COL n

    DOUT n DOUT n+1 DOUT n+2 DOUT n+3

    INTERNALCLOCK

    CLOCK SUSPENDClock suspend mode occurs when a column access/burst is inprogressandCKEisregisteredLOW.In theclocksuspendmode,theinternalclockisdeactivated,“freezing”the synchronous logic.

    ForeachpositiveclockedgeonwhichCKEissampledLOW,thenextinternalpositiveclockedgeissuspended.Any command or data present on the input pins at the time

    ofasuspendedinternalclockedgeisignored;anydatapresentontheDQpinsremainsdriven;andburstcountersare not incremented, as long as the clock is suspended. (See following examples.)

    ClocksuspendmodeisexitedbyregisteringCKEHIGH;the internal clock and related operation will resume on the subsequent positive clock edge.

    Clock Suspend During WRITE Burst

    Clock Suspend During READ Burst

  • Integrated Silicon Solution, Inc. — www.issi.com 33Rev. D01/30/08

    IS42S16400

    DON'T CARE

    CLK

    COMMAND

    BANK n

    BANK m

    ADDRESS

    DQ

    T0 T1 T2 T3 T4 T5 T6 T7

    NOP NOP NOP NOP NOP NOP

    DOUT a DOUT a+1 DOUT b DOUT b+1

    BANK n,COL a

    BANK m,COL b

    CAS Latency - 3 (BANK n)

    CAS Latency - 3 (BANK m)

    tRP - BANK n tRP - BANK m

    READ - APBANK n

    READ - APBANK m

    Page Active READ with Burst of 4 Interrupt Burst, Precharge Idle

    Page Active READ with Burst of 4 Precharge

    Internal States

    DON'T CARE

    CLK

    COMMAND

    BANK n

    BANK m

    ADDRESS

    DQM

    DQ

    T0 T1 T2 T3 T4 T5 T6 T7

    NOP NOP NOP NOP NOP NOP

    DOUT a DIN b DIN b+1 DIN b+2 DIN b+3

    BANK n,COL a

    BANK m,COL b

    CAS Latency - 3 (BANK n)

    tRP - BANK n tRP - BANK m

    WRITE - APBANK n

    WRITE - APBANK m

    READ with Burst of 4 Interrupt Burst, Precharge Idle

    Page Active WRITE with Burst of 4 Write-Back

    Internal States Page Active

    BURST READ/SINGLE WRITETheburstread/singlewritemodeisenteredbyprogrammingthe write burst mode bit (M9) in the mode register to a logic 1. In this mode, all WRITE commands result in the access of a single column location (burst of one), regardless of theprogrammedburstlength.READcommandsaccess columns according to the programmed burst length and sequence,justasinthenormalmodeofoperation(M9= 0).

    CONCURRENT AUTO PRECHARGEAnaccesscommand(READorWRITE)toanotherbankwhile an access command with auto precharge enabled is executingisnotallowedbySDRAMs,unlesstheSDRAMsupports CONCURRENT AUTO PRECHARGE. ISSI

    SDRAMssupportCONCURRENTAUTOPRECHARGE.FourcaseswhereCONCURRENTAUTOPRECHARGEoccurs are defined below.

    READ with Auto Precharge1.InterruptedbyaREAD(withorwithoutautoprecharge):

    AREADtobankmwill interruptaREADonbankn,CAS latency later.The PRECHARGE to bank n willbeginwhentheREADtobankmisregistered.

    2.InterruptedbyaWRITE(withorwithoutautoprecharge):AWRITEtobankmwillinterruptaREADonbanknwhenregistered.DQMshouldbeusedtwoclockspriortotheWRITEcommandtopreventbuscontention.ThePRECHARGEtobanknwillbeginwhentheWRITEtobank m is registered.

    Fig CAP 1 - READ With Auto Precharge interrupted by a READ

    Fig CAP 2 - READ With Auto Precharge interrupted by a WRITE

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    IS42S16400

    DON'T CARE

    CLK

    COMMAND

    BANK n

    BANK m

    ADDRESS

    DQ

    T0 T1 T2 T3 T4 T5 T6 T7

    NOP NOP NOP NOP NOP NOP

    DIN a DIN a+1 DOUT b DOUT b+1

    BANK n,COL a

    BANK m,COL b

    CAS Latency - 3 (BANK m)

    tRP - BANK ntRP - BANK m

    WRITE - APBANK n

    READ - APBANK m

    Page Active WRITE with Burst of 4 Interrupt Burst, Write-Back Precharge

    Page Active READ with Burst of 4 Precharge

    Internal States tWR - BANK n

    DON'T CARE

    CLK

    COMMAND

    BANK n

    BANK m

    ADDRESS

    DQ

    T0 T1 T2 T3 T4 T5 T6 T7

    NOP NOP NOP NOP NOP NOP

    BANK n,COL a

    BANK m,COL b

    tRP - BANK ntRP - BANK m

    WRITE - APBANK n

    WRITE - APBANK m

    Page Active WRITE with Burst of 4 Interrupt Burst, Write-Back Precharge

    Page Active WRITE with Burst of 4 Write-Back

    Internal States tWR - BANK n

    DIN a DIN a+1 DIN a+2 DIN b DIN b+1 DIN b+2 DIN b+3

    WRITE with Auto Precharge3.InterruptedbyaREAD(withorwithoutautoprecharge):

    AREADtobankmwill interruptaWRITEonbanknwhen registered, with the data-out appearing CAS latency later.ThePRECHARGEtobanknwillbeginaftertwr is met, where twrbeginswhentheREADtobankmisregistered.ThelastvalidWRITE to bank n will be data-in registeredoneclockpriortotheREADtobankm.

    4.InterruptedbyaWRITE(withorwithoutautoprecharge):AWRITE to bank m will interrupt a WRITE on bank n when registered.ThePRECHARGEtobanknwillbeginaftertwr is met, where twrbeginswhentheWRITEtobankmisregistered.ThelastvaliddataWRITEtobanknwillbedataregisteredoneclockpriortoaWRITEtobank m.

    Fig CAP 3 - WRITE With Auto Precharge interrupted by a READ

    Fig CAP 4 - WRITE With Auto Precharge interrupted by a WRITE

  • Integrated Silicon Solution, Inc. — www.issi.com 35Rev. D01/30/08

    IS42S16400

    INITIALIzE AND LOAD MODE REGISTER(1)

    DON'T CARE

    CLK

    CKE

    COMMAND

    DQM/DQML, DQMH

    A0-A9, A11

    A10

    BA0, BA1

    DQ

    tCH tCLtCK

    tCMH tCMS tCMH tCMS tCMH tCMS

    tCKS tCKH

    T0 T1 Tn+1 To+1 Tp+1 Tp+2 Tp+3

    tMRDtRCtRCtRP

    ROW

    ROW

    BANK

    tAS tAH

    tAS tAHCODE

    CODEALL BANKS

    SINGLE BANK

    ALL BANKS

    AUTOREFRESH

    AUTOREFRESH

    Load MODEREGISTER

    T = 100µs Min.

    Power-up: VCCand CLK stable

    Prechargeall banks

    AUTO REFRESH Program MODE REGISTER

    NOP PRECHARGE NOP NOP NOP ACTIVE

    T

    (2, 3, 4)AUTO REFRESH

    At least 2 Auto-Refresh Commands

    Notes:1. If CSisHighatclockHightime,allcommandsappliedareNOP.2.TheModeregistermaybeloadedpriortotheAuto-Refreshcyclesifdesired.3.JEDECandPC100specifythreeclocks.4.OutputsareguaranteedHigh-Zafterthecommandisissued.

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    IS42S16400

    POWER-DOWN MODE CYCLE

    CAS latency = 2, 3

    DON'T CARE

    CLK

    CKE

    COMMAND

    DQM/DQML, DQMH

    A0-A9, A11

    A10

    BA0, BA1

    DQ

    tAS tAH

    BANK

    tCHtCLtCK

    tCMS tCMH

    tCKS tCKH

    PRECHARGE NOP NOP NOP ACTIVE

    ALL BANKS

    SINGLE BANK

    ROW

    ROW

    BANK

    tCKStCKS

    Precharge allactive banks

    All banks idleTwo clock cycles Input buffers gatedoff while in

    power-down modeAll banks idle, enterpower-down mode Exit power-down mode

    T0 T1 T2 Tn+1 Tn+2

    High-Z

  • Integrated Silicon Solution, Inc. — www.issi.com 37Rev. D01/30/08

    IS42S16400

    CLOCK SUSPEND MODE

    Notes:1. CAS latency = 3, burst length = 22. A8, A9, and A11="Don'tCare"

    DON'T CARE

    CLK

    CKE

    COMMAND

    DQM/DQML, DQMH

    A0-A9, A11

    A10

    BA0, BA1

    DQ

    tCMS tCMH

    tAS tAH

    tAS tAH

    tAS tAH

    tCHtCLtCK

    tCMS tCMH

    tCKS tCKH

    COLUMN m(2)

    T0 T1 T2 T3 T4 T5 T6 T7 T8 T9

    READ NOP NOP NOP NOP NOP WRITE NOP

    tCKS tCKH

    BANK BANK

    COLUMN n(2)

    tAC tAC

    tOH

    tHZ

    DOUT m DOUT m+1

    tLZ

    UNDEFINED

    DOUT e+1

    tDS tDH

    DOUT e

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    AUTO-REFRESH CYCLE

    CAS latency = 2, 3

    tRP tRC tRC

    DON'T CARE

    CLK

    CKE

    COMMAND

    DQM/DQML, DQMH

    A0-A9, A11

    A10

    BA0, BA1

    DQ

    tAS tAH

    tCHtCLtCK

    tCMS tCMH

    tCKS tCKH

    T0 T1 T2 Tn+1 To+1

    ALL BANKS

    SINGLE BANK

    BANK(s)

    ROW

    ROW

    BANK

    High-Z

    PRECHARGE NOP NOP NOP ACTIVEAutoRefreshAuto

    Refresh

  • Integrated Silicon Solution, Inc. — www.issi.com 39Rev. D01/30/08

    IS42S16400

    SELF-REFRESH CYCLE

    CAS latency = 2, 3

    CLK

    CKE

    COMMAND

    DQM/DQML, DQMH

    A0-A9, A11

    A10

    BA0, BA1

    DQ

    tAS tAH

    BANK

    tCLtCHtCK

    tCMS tCMH

    tCKS tCKH

    ALL BANKS

    SINGLE BANK

    tCKS

    Precharge allactive banks

    CLK stable prior to exitingself refresh mode

    Enter selfrefresh mode

    Exit self refresh mode(Restart refresh time base)

    T0 T1 T2 Tn+1 To+1 To+2

    High-Z

    AutoRefresh

    AutoRefreshPRECHARGE NOP NOP NOP

    tCKS

    ≥ tRAS

    tRP tXSR

    DON'T CARE

  • 40 Integrated Silicon Solution, Inc. — www.issi.com Rev. D

    01/30/08

    IS42S16400

    READ WITHOUT AUTO PRECHARGE

    DON'T CARE

    UNDEFINED

    CLK

    CKE

    COMMAND

    DQM/DQML, DQMH

    A0-A9, A11

    A10

    BA0, BA1

    DQ

    tCMS tCMH

    ACTIVE NOP READ NOP NOP NOP PRECHARGE NOP ACTIVE

    tAS tAH

    tAS tAH

    tAS tAH

    ROW

    ROW

    BANK

    COLUMN m(2)

    tCHtCLtCK

    tCMS tCMH

    tCKS tCKH

    BANK

    tRCD CAS Latency

    tAC tAC tAC tAC

    tOH

    tHZ

    tOH

    DOUT m

    tOH

    DOUT m+1

    tOH

    DOUT m+2 DOUT m+3

    T0 T1 T2 T3 T4 T5 T6 T7 T8

    DISABLE AUTO PRECHARGE

    ROW

    ROW

    BANK

    tLZ

    tRAS

    tRCtRP

    ALL BANKS

    SINGLE BANK

    BANK

    Notes:1. CAS latency = 2, burst length = 42. A8, A9, and A11="Don'tCare"

  • Integrated Silicon Solution, Inc. — www.issi.com 41Rev. D01/30/08

    IS42S16400

    READ WITH AUTO PRECHARGE

    DON'T CARE

    UNDEFINED

    CLK

    CKE

    COMMAND

    DQM/DQML, DQMH

    A0-A9, A11

    A10

    BA0, BA1

    DQ

    tCMS tCMH

    ACTIVE NOP READ NOP NOP NOP NOP NOP ACTIVE

    tAS tAH

    tAS tAH

    tAS tAH

    ROW

    ROW

    BANK

    COLUMN m(2)

    tCHtCLtCK

    tCMS tCMH

    tCKS tCKH

    BANK

    tRCD

    tRAS

    tRC

    CAS Latency

    tAC tAC tAC tAC

    tOH

    tHZ

    tOH

    DOUT m

    tOH

    DOUT m+1

    tOH

    DOUT m+2 DOUT m+3

    T0 T1 T2 T3 T4 T5 T6 T7 T8

    tRP

    ENABLE AUTO PRECHARGE

    ROW

    ROW

    BANK

    tLZ

    Notes:1. CAS latency = 2, burst length = 42. A8, A9, and A11="Don'tCare"

  • 42 Integrated Silicon Solution, Inc. — www.issi.com Rev. D

    01/30/08

    IS42S16400

    SINGLE READ WITHOUT AUTO PRECHARGE

    DON'T CARE

    UNDEFINED

    CLK

    CKE

    COMMAND

    DQM/DQML, DQMH

    A0-A9, A11

    A10

    BA0, BA1

    DQ

    tCMS tCMH

    ACTIVE NOP READ NOP NOP PRECHARGE NOP ACTIVE NOP

    tAS tAH

    tAS tAH

    tAS tAH

    ROW

    ROW

    BANK

    COLUMN m(2)

    tCHtCLtCK

    tCMS tCMH

    tCKS tCKH

    BANK

    tRCD

    tRAS

    tRC

    CAS Latency

    tAC

    tHZ

    tOH

    DOUT m

    T0 T1 T2 T3 T4 T5 T6 T7 T8

    tRP

    DISABLE AUTO PRECHARGE

    ROW

    ROW

    BANK

    tLZ

    ALL BANKS

    SINGLE BANK

    BANK

    Notes:1. CAS latency = 2, burst length = 12. A8, A9, and A11="Don'tCare"

  • Integrated Silicon Solution, Inc. — www.issi.com 43Rev. D01/30/08

    IS42S16400

    SINGLE READ WITH AUTO PRECHARGE

    DON'T CARE

    UNDEFINED

    CLK

    CKE

    COMMAND

    DQM/DQML, DQMH

    A0-A9, A11

    A10

    BA0, BA1

    DQ

    tCMS tCMH

    ACTIVE NOP NOP NOP READ NOP NOP ACTIVE NOP

    tAS tAH

    tAS tAH

    tAS tAH

    ROW

    ROW

    BANK

    COLUMN m(2)

    tCHtCLtCK

    tCMS tCMH

    tCKS tCKH

    BANK

    tRCD

    tRAS

    tRC

    CAS Latency

    tAC

    tHZ

    tOH

    DOUT m

    T0 T1 T2 T3 T4 T5 T6 T7 T8

    tRP

    ENABLE AUTO PRECHARGE

    ROW

    ROW

    BANK

    Notes:1. CAS latency = 2, burst length = 12. A8, A9, and A11="Don'tCare"

  • 44 Integrated Silicon Solution, Inc. — www.issi.com Rev. D

    01/30/08

    IS42S16400

    ALTERNATING BANK READ ACCESSES

    BANK 0 BANK 3 BANK 3 BANK 0

    DON'T CARE

    CLK

    CKE

    COMMAND

    DQM/DQML, DQMH

    A0-A9, A11

    A10

    BA0, BA1

    DQ

    tCMS tCMH

    tAS tAH

    tAS tAH

    tAS tAH

    tRCD - BANK 0 CAS Latency - BANK 0 tRCD - BANK 0

    tRAS - BANK 0

    tRC - BANK 0

    tCHtCLtCK

    tCMS tCMH

    tCKS tCKH

    ACTIVE NOP READ NOP ACTIVE NOP READ NOP ACTIVE

    ROW

    ROW

    BANK 0

    ROW ROW

    tRRD tRCD - BANK 3

    tRP - BANK 0

    COLUMN m(2) ROW COLUMN b(2) ROW

    ENABLE AUTO PRECHARGE ENABLE AUTO PRECHARGE

    T0 T1 T2 T3 T4 T5 T6 T7 T8

    tAC

    tOH tOH tOH tOH tOH

    DOUT m DOUT m+1 DOUT m+2 DOUT m+3 DOUT b

    tAC tAC tAC tAC tAC

    tLZ

    CAS Latency - BANK 3

    Notes:1. CAS latency = 2, burst length = 42. A8, A9, and A11="Don'tCare"

  • Integrated Silicon Solution, Inc. — www.issi.com 45Rev. D01/30/08

    IS42S16400

    READ - FULL-PAGE BURST

    DON'T CARE

    UNDEFINED

    CLK

    CKE

    COMMAND

    DQM/DQML, DQMH

    A0-A9, A11

    A10

    BA0, BA1

    DQ

    tCMS tCMH

    ACTIVE NOP READ NOP NOP NOP NOP NOP BURST TERM NOP NOP

    tAS tAH

    tAS tAH

    tAS tAH

    ROW

    ROW

    BANK

    COLUMN m(2)

    tCHtCLtCK

    tCMS tCMH

    tCKS tCKH

    BANK

    tRCD CAS Latency

    tAC tACtAC tACtAC tHZ

    tLZ

    tAC

    tOH tOH tOH tOH tOH tOH

    DOUT m DOUT m+1 DOUT m+2 DOUT m-1 DOUT m DOUT m+1

    each row (x4) has1,024 locations

    Full pagecompletion

    Full-page burst not self-terminating.Use BURST TERMINATE command.

    T0 T1 T2 T3 T4 T5 T6 Tn+1 Tn+2 Tn+3 Tn+4

    Notes:1. CAS latency = 2, burst length = full page2. A8, A9, and A11="Don'tCare"

  • 46 Integrated Silicon Solution, Inc. — www.issi.com Rev. D

    01/30/08

    IS42S16400

    READ - DQM OPERATION

    DON'T CARE

    UNDEFINED

    CLK

    CKE

    COMMAND

    DQM/DQML, DQMH

    A0-A9, A11

    A10

    BA0, BA1

    DQ

    tCMS tCMH

    ACTIVE NOP READ NOP NOP NOP NOP NOP NOP

    tAS tAH

    tAS tAH

    tAS tAH

    ENABLE AUTO PRECHARGE

    DISABLE AUTO PRECHARGE

    ROW

    ROW

    BANK

    tRCD CAS Latency

    DOUT m DOUT m+2 DOUT m+3

    COLUMN m(2)

    BANK

    tCHtCLtCK

    tCMS tCMH

    tCKS tCKH

    tOHtOHtOH tACtAC

    tACtHZ tHZtLZ tLZ

    T0 T1 T2 T3 T4 T5 T6 T7 T8

    Notes:1. CAS latency = 2, burst length = 42. A8, A9, and A11="Don'tCare"

  • Integrated Silicon Solution, Inc. — www.issi.com 47Rev. D01/30/08

    IS42S16400

    WRITE - WITHOUT AUTO PRECHARGE

    DON'T CARE

    CLK

    CKE

    COMMAND

    DQM/DQML, DQMH

    A0-A9, A11

    A10

    BA0, BA1

    DQ

    tCMS tCMH

    tAS tAH

    tAS tAH

    tAS tAH

    tRCD

    tRAStRC

    tCHtCLtCK

    tCMS tCMH

    tCKS tCKH

    ACTIVE NOP WRITE NOP NOP NOP PRECHARGE NOP ACTIVE

    tWR(3) tRP

    COLUMN m(2) ROW

    DISABLE AUTO PRECHARGEROW

    ROW

    ROW

    BANK

    tDS tDH tDS tDH tDS tDHtDS tDH

    DIN m DIN m+1 DIN m+2 DIN m+3

    BANK BANK BANK

    ALL BANKS

    SINGLE BANK

    T0 T1 T2 T3 T4 T5 T6 T7 T8

    Notes:1. burst length = 42. A8, A9, and A11="Don'tCare"3. tras must not be violated

  • 48 Integrated Silicon Solution, Inc. — www.issi.com Rev. D

    01/30/08

    IS42S16400

    WRITE - WITH AUTO PRECHARGE

    DON'T CARE

    CLK

    CKE

    COMMAND

    DQM/DQML, DQMH

    A0-A9, A11

    A10

    BA0, BA1

    DQ

    tCMS tCMH

    tAS tAH

    tAS tAH

    tAS tAH

    tRCD

    tRAStRC

    tCHtCLtCK

    tCMS tCMH

    tCKS tCKH

    ACTIVE NOP WRITE NOP NOP NOP NOP NOP NOP ACTIVE

    tWR tRP

    COLUMN m(2) ROW

    BANK BANK

    ENABLE AUTO PRECHARGEROW

    ROW

    ROW

    BANK

    tDS tDH tDS tDH tDS tDHtDS tDH

    DIN m DIN m+1 DIN m+2 DIN m+3

    T0 T1 T2 T3 T4 T5 T6 T7 T8 T9

    Notes:1. burst length = 42. A8, A9, and A11="Don'tCare"

  • Integrated Silicon Solution, Inc. — www.issi.com 49Rev. D01/30/08

    IS42S16400

    SINGLE WRITE - WITHOUT AUTO PRECHARGE

    DON'T CARE

    CLK

    CKE

    COMMAND

    DQM/DQML, DQMH

    A0-A9, A11

    A10

    BA0, BA1

    DQ

    tCMS tCMH

    tAS tAH

    tAS tAH

    tAS tAH

    tDS tDH

    tRCD

    tRAStRC

    tCHtCLtCK

    tCMS tCMH

    tCKS tCKH

    ACTIVE NOP WRITE NOP(4) NOP(4) PRECHARGE NOP ACTIVE NOP

    tWR(3) tRP

    DISABLE AUTO PRECHARGE

    ROW

    ROW

    ROW

    BANK

    DIN m

    COLUMN m(2) ROW

    BANK BANK BANK

    ALL BANKS

    SINGLE BANK

    T0 T1 T2 T3 T4 T5 T6 T7 T8

    Notes:1. burst length = 12. A8, A9, and A11="Don'tCare"3. tras must not be violated

  • 50 Integrated Silicon Solution, Inc. — www.issi.com Rev. D

    01/30/08

    IS42S16400

    SINGLE WRITE - WITH AUTO PRECHARGE

    DON'T CARE

    CLK

    CKE

    COMMAND

    DQM/DQML, DQMH

    A0-A9, A11

    A10

    BA0, BA1

    DQ

    tCMS tCMH

    tAS tAH

    tAS tAH

    tAS tAH

    tDS tDH

    tRCD

    tRAStRC

    tCHtCLtCK

    tCMS tCMH

    tCKS tCKH

    ACTIVE NOP(3) NOP(3) NOP(3) WRITE NOP NOP NOP ACTIVE NOP

    tWR tRP

    COLUMN m(2) ROW

    BANK BANK

    ENABLE AUTO PRECHARGE

    ROW

    ROW

    ROW

    BANK

    DIN m

    T0 T1 T2 T3 T4 T5 T6 T7 T8 T9

    Notes:1. burst length = 12. A8, A9, and A11="Don'tCare"

  • Integrated Silicon Solution, Inc. — www.issi.com 51Rev. D01/30/08

    IS42S16400

    ALTERNATING BANK WRITE ACCESS

    BANK 0 BANK 1 BANK 1 BANK 0

    DON'T CARE

    CLK

    CKE

    COMMAND

    DQM/DQML, DQMH

    A0-A9, A11

    A10

    BA0, BA1

    DQ

    tCMS tCMH

    tAS tAH

    tAS tAH

    tAS tAH

    tDS tDH tDS tDH tDS tDH

    tRCD - BANK 0 tRCD - BANK 0tWR - BANK 1

    tRAS - BANK 0tRC - BANK 0

    tCHtCLtCK

    tDS tDH tDS tDH tDS tDH tDS tDH tDS tDH

    tCMS tCMH

    tCKS tCKH

    ACTIVE NOP WRITE NOP ACTIVE NOP WRITE NOP NOP ACTIVE

    DIN m DIN m+1 DIN m+2 DIN m+3 DIN b DIN b+1 DIN b+2 DIN b+3

    ROW

    ROW

    BANK 0

    ROW ROW

    tRRD tRCD - BANK 1

    tWR - BANK 0 tRP - BANK 0

    COLUMN m(2) ROW COLUMN b(2) ROW

    ENABLE AUTO PRECHARGE ENABLE AUTO PRECHARGE

    T0 T1 T2 T3 T4 T5 T6 T7 T8 T9

    Notes:1. burst length = 42. A8, A9, and A11="Don'tCare"

  • 52 Integrated Silicon Solution, Inc. — www.issi.com Rev. D

    01/30/08

    IS42S16400

    DON'T CARE

    CLK

    CKE

    COMMAND

    DQM/DQML, DQMH

    A0-A9, A11

    A10

    BA0, BA1

    DQ

    tCMS tCMH

    ACTIVE NOP WRITE NOP NOP NOP NOP BURST TERM NOP

    tAS tAH

    tAS tAH

    tAS tAH

    tDS tDH tDS tDH tDS tDH

    ROW

    ROW

    BANK

    tRCD

    DIN m DIN m+1 DIN m+2 DIN m+3 DIN m-1

    COLUMN m(2)

    tCHtCLtCK

    tDS tDH tDS tDH tDS tDH

    tCMS tCMH

    tCKS tCKH

    BANK

    Full page completed

    T0 T1 T2 T3 T4 T5 Tn+1 Tn+2

    WRITE - FULL PAGE BURST

    Notes:1. burst length = full page2. A8, A9, and A11="Don'tCare"

  • Integrated Silicon Solution, Inc. — www.issi.com 53Rev. D01/30/08

    IS42S16400

    DON'T CARE

    CLK

    CKE

    COMMAND

    DQM/DQML, DQMH

    A0-A9, A11

    A10

    BA0, BA1

    DQ

    tCMS tCMH

    ACTIVE NOP WRITE NOP NOP NOP NOP NOP

    tAS tAH

    tAS tAH

    tAS tAH

    tDS tDH tDS tDH tDS tDH

    ENABLE AUTO PRECHARGE

    DISABLE AUTO PRECHARGE

    ROW

    ROW

    BANK

    tRCD

    DIN m DIN m+2 DIN m+3

    COLUMN m(2)

    BANK

    tCHtCLtCK

    tCMS tCMH

    tCKS tCKH

    T0 T1 T2 T3 T4 T5 T6 T7

    WRITE - DQM OPERATION

    Notes:1. burst length = 42. A8, A9, and A11="Don'tCare"

  • 54 Integrated Silicon Solution, Inc. — www.issi.com Rev. D

    01/30/08

    IS42S16400

    ORDERING INFORMATION

    Commercial Range: 0°C to 70°C Frequency Speed (ns) Order Part No. Package

    166MHz 6 IS42S16400-6TL 400-milTSOPII,Lead-free

    143MHz 7 IS42S16400-7TL 400-milTSOPII,Lead-free

    Industrial Range: -40°C to 85°C Frequency Speed (ns) Order Part No. Package

    166MHz 6 IS42S16400-6TLI 400-milTSOPII,Lead-free

    143MHz 7 IS42S16400-7TLI 400-milTSOPII,Lead-free

  • PACKAGING INFORMATION

    Integrated Silicon Solution, Inc. 1Rev. D03/13/07

    Plastic TSOP 54–Pin, 86-PinPackage Code: T (Type II)

    Plastic TSOP (T - Type II)Millimeters Inches

    Symbol Min Max Min MaxRef. Std.

    No. Leads (N) 54

    A — 1.20 — 0.047A1 0.05 0.15 0.002 0.006A2 — — — —b 0.30 0.45 0.012 0.018C 0.12 0.21 0.005 0.0083D 22.02 22.42 0.867 0.8827E1 10.03 10.29 0.395 0.405E 11.56 11.96 0.455 0.471e 0.80 BSC 0.031 BSCL 0.40 0.60 0.016 0.024

    L1 — — — — ZD 0.71 REF

    α 0° 8° 0° 8°

    D

    SEATING PLANE

    be C

    1 N/2

    N/2+1N

    E1

    A1

    A

    E

    L α

    ZD

    Notes:1. Controlling dimension: millimieters,

    unless otherwise specified.2. BSC = Basic lead spacing between

    centers.3. Dimensions D and E1 do not include

    mold flash protrusions and should bemeasured from the bottom of thepackage.

    4. Formed leads shall be planar withrespect to one another within 0.004inches at the seating plane.

    Plastic TSOP (T - Type II)Millimeters Inches

    Symbol Min Max Min MaxRef. Std.

    No. Leads (N) 86

    A — 1.20 — 0.047A1 0.05 0.15 0.002 0.006A2 0.95 1.05 0.037 0.041b 0.17 0.27 0.007 0.011C 0.12 0.21 0.005 0.008D 22.02 22.42 0.867 0.8827E1 10.03 10.29 0.395 0.405E 11.56 11.96 0.455 0.471e 0.50 BSC 0.020 BSCL 0.40 0.60 0.016 0.024

    L1 0.80 REF 0.031 REF ZD 0.61 REF 0.024 BSC

    α 0° 8° 0° 8°