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integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 1 rev. a 12/09/03 is42s16400b1 issi ? copyright ? 2003 integrated silicon solution, inc. all rights reserved. issi reserves the right to make changes to this speci fication 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 advise d to obtain the latest version of this device specification before relying on any published information and before placing orders for products. features ? clock frequency: 133 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 overview issi 's 64mb synchronous dram is42s16400b1 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 december 2003 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 v dd power gnd ground v dd q power supply for dq pin gnd q ground for dq pin nc no connection
is42s16400b1 issi ? 2 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 general description the 64mb sdram is a high speed cmos, dynamic random-access memory designed to operate in 3.3v memory systems containing 67,108,864 bits. internally configured as a quad-bank dram with a synchronous interface. each 16,777,216-bit bank is organized as 4,096 rows by 256 columns by 16 bits. the 64mb sdram includes an auto refresh mode, and a power-saving, power-down mode. all signals are registered on the positive edge of the clock signal, clk. all inputs and outputs are lvttl compatible. the 64mb sdram has the ability to synchronously burst data 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 sequence is available with the auto precharge function enabled. 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. the registration of an active command begins accesses, followed by a read or write command. the active command in conjunction with address bits registered are used to select the bank and row to be accessed (ba0, ba1 select the bank; a0-a11 select the row). the read or write commands in conjunction with address bits reg- istered are used to select the starting column location for the burst access. programmable read or write burst lengths consist of 1, 2, 4 and 8 locations, or full page, with a burst terminate option. clk cke cs ras cas we a11 a9 a8 a7 a6 a5 a4 a3 a2 a1 a0 ba0 ba1 a10 command decoder & clock generator mode register refresh controller refresh counter self refresh controller row address latch multiplexer column address latch burst counter column address buffer column decoder data in buffer data out buffer dqm dq 0-15 v dd /v ddq gnd/gndq 11 11 8 11 11 8 16 16 16 16 256k (x 16) 4096 4096 4096 row decoder 4096 memory cell array bank 0 sense amp i/o gate bank control logic row address buffer functional block diagram
is42s16400b1 issi ? integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 3 rev. a 12/09/03 pin functions symbol pin no. type function (in detail) a0-a11 23 to 26 input pin address inputs: a0-a11 are sampled during the active 29 to 34 command (row-address a0-a11) and read/write command (a0-a7 22, 35 with a10 defining auto precharge) to select one location out of the memory array in the respective bank. a10 is sampled during a precharge command to determine if all banks are to be precharged (a10 high) or bank selected by ba0, ba1 (low). the address inputs also provide the op-code during a load mode register command. ba0, ba1 20, 21 input pin bank select address: ba0 and ba1 defines which bank the active, read, write or precharge command is being applied. cas 17 input pin cas , in conjunction with the ras and we , forms the device command. see the "command truth table" for details on device commands. cke 37 input pin the cke input determines whether the clk input is enabled. the next rising edge of the clk signal will be valid when is cke high and invalid when low. when cke is low, the device will be in either power-down mode, clock suspend mode, or self refresh mode. cke is an asynchronous i nput. clk 38 input pin clk is the master clock input for this device. except for cke, all inputs to this device are acquired in synchronization with the rising edge of this pin. cs 19 input pin the cs input determines whether command input is enabled within the device. command input is enabled when cs is low, and disabled with cs is high. the device remains in the previous state when cs is high. dq0 to 2, 4, 5, 7, 8, 10, dq pin dq0 to dq15 are i/o pins. i/o through these pins can be controlled in byte units dq15 11,13, 42, 44, 45, using the ldqm and udqm pins. 47, 48, 50, 51, 53 ldqm, 15, 39 input pin ldqm and udqm control the lower and upper bytes of the i/o buffers. in read udqm m ode, ldqm and udqm control the output buffer. when ldqm or udqm is low, the corresponding buffer byte is enabled, and when high, disabled. the outputs go to the high impedance state when ldqm/udqm is high. this function corresponds to oe in conventional drams. in write mode, ldqm and udqm control the input buffer. when ldqm or udqm is low, the corresponding buffer byte is enabled, and data can be written to the device. when ldqm or udqm is high, input data is masked and cannot be written to the device. ras 18 input pin ras , in conjunction with cas and we , forms the device command. see the "command truth table" item for details on device commands. we 16 input pin we , in conjunction with ras and cas , forms the device command. see the "command truth table" item for details on device commands. v ddq 3, 9, 43, 49 power supply pin v ddq is the output buffer power supply. v dd 1, 14, 27 power supply pin v dd is the device internal power supply. gnd q 6, 12, 46, 52 power supply pin gnd q is the output buffer ground. gnd 28, 41, 54 power supply pin gnd is the device internal ground.
is42s16400b1 issi ? 4 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 function (in detail) a0-a11 are address inputs sampled during the active (row-address a0-a11) and read/write command (a0-a7 with a10 defining auto precharge) . a10 is sampled during a precharge command to determine if all banks are to be precharged (a10 high) or bank selected by ba0, ba1 (low) . the address inputs also provide the op-code during a load mode register command. bank select address (ba0 and ba1) defines which bank the active, read, write or precharge command is being applied. cas , in conjunction with the ras and we , forms the device command. see the ?command truth table? for details on device commands. the cke input determines whether the clk input is enabled. the next rising edge of the clk signal will be valid when is cke high and invalid when low. when cke is low, the device will be in either power-down mode, clock suspend mode, or self-refresh mode. cke is an asynchronous input. clk is the master clock input for this device. except for cke, all inputs to this device are acquired in synchroni- zation with the rising edge of this pin. the cs input determines whether command input is enabled within the device. command input is enabled when cs is low, and disabled with cs is high. the device remains in the previous state when cs is high. dq0 to dq15 are dq pins. dq through these pins can be controlled in byte units using the ldqm and udqm pins. ldqm and udqm control the lower and upper bytes of the dq buffers. in read mode, ldqm and udqm control the output buffer. when ldqm or udqm is low, the corre- sponding buffer byte is enabled, and when high, dis- abled. the outputs go to the high impedance state when ldqm/udqm is high. this function corresponds to oe in conventional drams. in write mode, ldqm and udqm control the input buffer. when ldqm or udqm is low, the corresponding buffer byte is enabled, and data can be written to the device. when ldqm or udqm is high, input data is masked and cannot be written to the device. ras , in conjunction with cas and we , forms the device command. see the ?command truth table? item for details on device commands. we , in conjunction with ras and cas , forms the device command. see the ?command truth table? item for details on device commands. v ddq is the output buffer power supply. v dd is the device internal power supply. gnd q is the output buffer ground. gnd is the device internal ground. read the read command selects the bank from ba0, ba1 inputs and starts a burst read access to an active row. inputs a0-a7 provides the starting column location. when a10 is high, this command functions as an auto precharge command. when the auto precharge is selected, the row being accessed will be precharged at the end of the read burst. the row will remain open for subsequent accesses when auto precharge is not selected. dq?s read data is subject to the logic level on the dqm inputs two clocks earlier. when a given dqm signal was registered high, the corresponding dq?s will be high-z two clocks later. dq?s will provide valid data when the dqm signal was registered low. write a 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 not auto-precharge is used is deter- mined by a10. the row being accessed will be precharged at the end of the write burst, if auto precharge is selected. if auto precharge is not selected, the row will remain open for subsequent accesses. a memory array is written with corresponding input data on dq?s and dqm input logic level appearing at the same time. data will be written to memory when dqm signal is low. when dqm is high, the corresponding data inputs will be ignored, and a write will not be executed to that byte/column location. precharge the precharge command is used to deactivate the open row in a particular bank or the open row in all banks. ba0, ba1 can be used to select which bank is precharged or they are treated as ?don?t care?. a10 determined whether one or all banks are precharged. after executing this command, the next command for the selected banks(s) is executed after passage of the period t rp , which is the period required for bank precharging. once a bank has been precharged, it is in the idle state and must be activated prior to any read or write commands being issued to that bank. auto precharge the auto precharge function ensures that the precharge is initiated at the earliest valid stage within a burst. this function allows for individual-bank precharge without requiring an explicit command. a10 to enables the auto precharge function in conjunction with a spe- cific read or write command. for each individual read or write command, auto precharge is either
is42s16400b1 issi ? integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 5 rev. a 12/09/03 enabled or disabled. auto precharge does not apply except in full-page burst mode. upon completion of the read or write burst, a precharge of the bank/row that is addressed is automatically performed. auto refresh command this command executes the auto refresh operation. the row address and bank to be refreshed are automatically generated during this operation. the stipulated period (t rc ) is required for a single refresh operation, and no other commands can be executed during this period. this com- mand is executed at least 4096 times every 64ms. during an auto refresh command, address bits are ?don?t care?. this command corresponds to cbr auto-refresh. self refresh during the self refresh operation, the row address to be refreshed, the bank, and the refresh interval are generated automatically internally. self refresh can be used to retain data in the sdram without external clocking, even if the rest of the system is powered down. the self refresh operation is started by dropping the cke pin from high to low. during the self refresh operation all other inputs to the sdram become ?don?t care?. the device must remain in self refresh mode for a minimum period equal to t ras or may remain in self refresh mode for an indefinite period beyond that. the self- refresh operation continues as long as the cke pin remains low and there is no need for external control of any other pins. the next command cannot be executed until the device internal recovery period (t rc ) has elapsed. once cke goes high, the nop command must be issued (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 be refreshed, an auto-refresh should immediately be performed for all addresses. burst terminate the burst terminate command forcibly terminates the burst read and write operations by truncating either fixed- length or full-page bursts and the most recently registered read or write command prior to the burst termi- nate. command inhibit command inhibit prevents new commands from being executed. operations in progress are not affected, apart from whether the clk signal is enabled no operation when cs is low, the nop command prevents unwanted commands from being registered during idle or wait states. load mode register during the load mode register command the mode register is loaded from a0-a11. this command can only be issued when all banks are idle. active command when the active command is activated, ba0, ba1 inputs selects a bank to be accessed, and the address inputs on a0-a11 selects the row. until a precharge command is issued to the bank, the row remains open for accesses.
is42s16400b1 issi ? 6 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 truth table ? commands and dqm operation (1) function cs cs cs cs cs ras ras ras ras ras cas cas cas cas cas we we we we we dqm addr dqs command inhibit (nop) h x x x x x x no operation (nop) l h h h x x x active (select bank and activate row) (3) l l h h x bank/row x read (select bank/column, start read burst) (4) lhlhl/h (8) bank/col x write (select bank/column, start write burst) (4) l h l l l/h (8) bank/col valid burst terminate l h h l x x active precharge (deactivate row in bank or banks) (5) l l h l x code x auto refresh or self refresh (6,7) lllhxxx (enter self refresh mode) load mode register (2) l l l l x op-code x write enable/output enable (8) ? ? ? ? l ? active write inhibit/output high-z (8) ? ? ? ? h ? high-z notes: 1. cke is high for all commands except self refresh. 2. a0-a11 define the op-code written to the mode register. 3. a0-a11 provide row address, and ba0, ba1 determine which bank is made active. 4. a0-a7 (x16) provide column address; a10 high enables the auto precharge feature (nonpersistent), while a10 low disables auto precharge; ba0, ba1 determine which bank is being read from or written to. 5. a10 low: ba0, ba1 determine the bank being precharged. a10 high: all banks precharged and ba0, ba1 are ?don?t care.? 6. auto refresh if cke is high, self refresh if cke is low. 7. internal refresh counter controls row addressing; all inputs and i/os are ?don?t care? except for cke. 8. activates or deactivates the dqs during writes (zero-clock delay) and reads (two-clock delay).
is42s16400b1 issi ? integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 7 rev. a 12/09/03 truth table ? current state bank n, command to bank n (1-6) current state command (action) cs ras cas we any command inhibit (nop/continue previous operation) hx xx no operation (nop/continue previous operation) lh hh idle active (select and activate row) l l h h auto refresh (7) ll lh load mode register (7) ll ll precharge (11) ll hl row active read (select column and start read burst) (10) lh lh write (select column and start write burst) (10) lh ll precharge (deactivate row in bank or banks) (8) ll hl read read (select column and start new read burst) (10) lh lh (auto write (select column and start write burst) (10) lh ll precharge precharge (truncate read burst, start precharge) (8) ll hl disabled) burst terminate (9) lh hl write read (select column and start read burst) (10) lh lh (auto write (select column and start new write burst) (10) lh ll precharge precharge (truncate write burst, start precharge) (8) ll hl disabled) burst terminate (9) lh hl truth table ? cke (1-4) current state commandn actionn cken-1 cken power-down x maintain power-down l l self refresh x maintain self refresh l l clock suspend x maintain clock suspend l l power-down (5) command inhibit or nop exit power-down l h self refresh (6) command inhibit or nop exit self refresh l h clock suspend (7) x exit clock suspend l h all banks idle command inhibit or nop power-down entry h l all banks idle auto refresh self ref resh entry h l reading or writing valid clock suspend entry h l see truth table ? current state bank n, command to bank n hh notes: 1. cken is the logic state of cke at clock edge n ; cken-1 was the state of cke at the previous clock edge. 2. current state is the state of the sdram immediately prior to clock edge n . 3. commandn is the command registered at clock edge n , and actionn is a result of commandn. 4. all states and sequences not shown are illegal or reserved. 5. exiting power-down at clock edge n will put the device in the all banks idle state in time for clock edge n+1 (provided that t cks is met) . 6. exiting self refresh at clock edge n will put the device in all banks idle state once t xsr is met. command inhibit or nop commands should be issued on clock edges occurring during the t xsr period. a minimum of two nop commands must be sent during t xsr 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 .
is42s16400b1 issi ? 8 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 note: 1. this table applies when cke n-1 was high and cke n is high (see truth table - cke) and after t xsr has been met (if the previous state was self refresh). 2. this table is bank-specific, except where noted; i.e., the current state is for a specific bank and the commands shown are th ose allowed to be issued to that bank when in that state. exceptions are covered in the notes below. 3. current state definitions: idle: the bank has been precharged, and t rp has been met. row active: a row in the bank has been activated, and t rcd has been met. no data bursts/accesses and no register accesses are in progress. read: a read burst has been initiated, with auto precharge disabled, and has not yet terminated or been terminated. write: a write burst has been initiated, with auto precharge disabled, and has not yet terminated or been terminated. 4. the following states must not be interrupted by a command issued to the same bank. command inhibit or nop commands, or allowable commands to the other bank should be issued on any clock edge occurring during these states. allowable commands to the other bank are determined by its current state and current state bank n truth tables. precharging: starts with registration of a precharge command and ends when t rp is met. once t rp is met, the bank will be in the idle state. row activating: starts with registration of an active command and ends when t rcd is met. once t rcd is met, the bank will be in the row active state. read w/auto precharge enabled: starts with registration of a read command with auto precharge enabled and ends when t rp has been met. once t rp is met, the bank will be in the idle state. write w/auto precharge enabled: starts with registration of a write command with auto precharge enabled and ends when t rp has been met. once t rp is met, the bank will be in the idle state. 5. the following states must not be interrupted by any executable command; command inhibit or nop commands must be applied on each positive clock edge during these states. refreshing: starts with registration of an auto refresh command and ends when t rc is met. once t rc is met, the sdram will be in the all banks idle state. accessing mode register: starts with registration of a load mode register command and ends when t mrd has been met. once t mrd is met, the sdram will be in the all banks idle state. precharging all: starts with registration of a precharge all command and ends when t rp is met. once t rp is met, all banks will be in the idle state. 6. all states and sequences not shown are illegal or reserved. 7. not bank-specific; requires that all banks are idle. 8. may or may not be bank-specific; if all banks are to be precharged, all must be in a valid state for precharging. 9. not bank-specific; burst terminate affects the most recent read or write burst, regardless of bank. 10. reads or writes listed in the command (action) column include reads or writes with auto precharge enabled and reads or writes with auto precharge disabled. 11. does not affect the state of the bank and acts as a nop to that bank.
is42s16400b1 issi ? integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 9 rev. a 12/09/03 truth table ? current state bank n, command to bank m (1-6) current state command (action) cs ras cas we any command inhibit (nop/continue previous operation) h x x x no operation (nop/continue previous operation) l h h h idle any command otherwise allowed to bank m xx xx row active (select and activate row) l l h h activating, read (select column and start read burst) (7) lh lh active, or write (select column and start write burst) (7) lh ll precharging precharge l l h l read active (select and activate row) l l h h (auto read (select column and start new read burst) (7,10) lh lh precharge write (select column and start write burst) (7,11) lh ll disabled) precharge (9) ll hl write active (select and activate row) l l h h (auto read (select column and start read burst) (7,12) lh lh precharge write (select column and start new write burst) (7,13) lh ll disabled) precharge (9) ll hl read active (select and activate row) l l h h (with auto read (select column and start new read burst) (7,8,14) lh lh precharge) write (select column and start write burst) (7,8,15) lh ll precharge (9) ll hl write active (select and activate row) l l h h (with auto read (select column and start read burst) (7,8,16) lh lh precharge) write (select column and start new write burst) (7,8,17) lh ll precharge (9) ll hl note: 1. this table applies when cke n-1 was high and cke n is high (truth table - cke) and after t xsr has been met (if the previous state was self refresh). 2. this table describes alternate bank operation, except where noted; i.e., the current state is for bank n 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) . exceptions are covered in the notes below. 3. current state definitions: idle: the bank has been precharged, and t rp has been met. row active: a row in the bank has been activated, and t rcd has been met. no data bursts/accesses and no register accesses are in progress. read: a read burst has been initiated, with auto precharge disabled, and has not yet terminated or been terminated. write: a write burst has been initiated, with auto precharge disabled, and has not yet terminated or been terminated. read w/auto precharge enabled: starts with registration of a read command with auto precharge enabled, and ends when t rp has been met. once t rp is met, the bank will be in the idle state. write w/auto precharge enabled: starts with registration of a write command with auto precharge enabled, and ends when t rp has been met. once t rp is met, the bank will be in the idle state. 4. auto refresh, self refresh and load mode register commands may only be issued when all banks are idle. 5. a burst terminate command cannot be issued to another bank; it applies to the bank represented by the current state only. 6. all states and sequences not shown are illegal or reserved.
is42s16400b1 issi ? 10 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 7. reads or writes to bank m listed in the command (action) column include reads or writes with auto precharge enabled and reads or writes with auto precharge disabled. 8. concurrent auto precharge: bank n will initiate the auto precharge command when its burst has been inter- rupted by bank m?s burst. 9. burst in bank n continues as initiated. 10. for a read without auto precharge interrupted by a read (with or without auto precharge), the read to bank m will interrupt the read on bank n, cas latency later (consecutive read bursts). 11. for a read without auto precharge interrupted by a write (with or without auto precharge), the write to bank m will interrup t the read on bank n when registered (read to write). dqm should be used one clock prior to the write command to prevent bus contention. 12. for a write without auto precharge interrupted by a read (with or without auto precharge), the read to bank m will interrupt the write on bank n when registered (write to read), with the data-out appearing cas latency later. the last valid write to bank n will be data-in registered one clock prior to the read to bank m. 13. for a write without auto precharge interrupted by a write (with or without auto precharge), the write to bank m will interru pt the write on bank n when registered (write to write). the last valid write to bank n will be data-in registered one clock prior to the read to bank m. 14. for a read with auto precharge interrupted by a read (with or without auto precharge), the read to bank m will interrupt the read on bank n, cas latency later. the precharge to bank n will begin when the read to bank m is registered (fig cap 1). 15. for a read with auto precharge interrupted by a write (with or without auto precharge), the write to bank m will interrupt t he read on bank n when registered. dqm should be used two clocks prior to the write command to prevent bus contention. the precharge to bank n will begin when the write to bank m is registered (fig cap 2). 16. for a write with auto precharge interrupted by a read (with or without auto precharge), the read to bank m will interrupt th e write on bank n when registered, with the data-out appearing cas latency later. the precharge to bank n will begin after t wr is met, where t wr begins when the read to bank m is registered. the last valid write to bank n will be data-in registered one clock prior to the read to bank m (fig cap 3). 17. for a write with auto precharge interrupted by a write (with or without auto precharge), the write to bank m will interrupt the write on bank n when registered. the precharge to bank n will begin after t wr is met, where t wr begins when the write to bank m is registered. the last valid write to bank n will be data registered one clock prior to the write to bank m (fig cap 4).
is42s16400b1 issi ? integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 11 rev. a 12/09/03 absolute maximum ratings (1) symbol par ameters rating unit v dd max maximum supply voltage ?1.0 to +4.6 v v ddq max maximum supply voltage for output buffer ?1.0 to +4.6 v v in input voltage ?1.0 to +4.6 v v out output voltage ?1.0 to +4.6 v p d max allowable power dissipation 1 w i cs output shorted current 50 ma t opr operating temperature com. 0 to +70 c t stg storage temperature ?55 to +150 c dc recommended operating conditions (2) ( at t a = 0 to +70c) symbol parameter min. typ. max. unit v dd , v ddq supply voltage 3.0 3.3 3.6 v v ih input high voltage 2.0 ? v dd + 0.3 v v il input low voltage -0.3 ? +0.8 v capacitance characteristics (1,2) (at t a = 0 to +25c, v dd = v ddq = 3.3 0.3v, f = 1 mhz) symbol parameter typ. max. unit c in1 input capacitance: a0-a11, ba0, ba1 ? 4 pf c in2 input capacitance: (clk, cke, cs , ras , cas , we , ldqm, udqm) ? 4 pf ci/o data input/output capacitance: i/o0-i/o15 ? 5 pf notes: 1. stress greater than those listed under absolute maximum ratings may cause permanent damage to the device. this is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operati onal sections of this specification is not implied. exposure to absolute maximum rating conditions for extended periods may affect reliability. 2. all voltages are referenced to gnd.
is42s16400b1 issi ? 12 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 dc electrical characteristics (recommended operation conditions unless otherwise noted.) symbol parameter test condition speed min. max. unit i il input leakage current 0v v in v dd , with pins other than ?5 5 a the tested pin at 0v i ol output leakage current output is disabled, 0v v out v dd ?5 5 a v oh output high voltage level i out = ?2 ma 2.4 ? v v ol output low voltage level i out = +2 ma ? 0.4 v i cc1 operating current (1,2) one bank operation, cas latency = 3 com. -7 ? 120 ma burst length=1 t rc t rc (min.) i out = 0ma i cc2p precharge standby current cke v il ( max )t ck = t ck ( min ) i cc2ps (in power-down mode) t ck = com. ? ? 2 ma i cc2n precharge standby current cke v ih ( min )t ck = t ck ( min )??30ma i cc2ns (in non power-down mode) t ck = com. ? ? 15 ma i cc3p active standby current cke v il ( max )t ck = t ck ( min ) com. ? ? 10 ma i cc3ps (in power-down mode) t ck = com. ? ? 10 ma i cc3n active standby current cke v ih ( min )t ck = t ck ( min )??40ma i cc3ns (in non power-down mode) t ck = com. ? ? 20 ma i cc4 operating current t ck = t ck ( min ) cas latency = 3 com. -7 ? 90 ma (in burst mode) (1) i out = 0ma cas latency = 2 com. -7 ? 90 ma i cc5 auto-refresh current t rc = t rc ( min ) cas latency = 3 com. -7 ? 130 ma cas latency = 2 com. -7 ? 100 ma i cc6 self-refresh current cke 0.2v ? ? 1.5 ma notes: 1. these are the values at the minimum cycle time. since the currents are transient, these values decrease as the cycle time increases. also note that a bypass capacitor of at least 0.01 f should be inserted between v dd and gnd for each memory chip to suppress power supply voltage noise (voltage drops) due to these transient currents. 2. icc 1 and icc 4 depend on the output load. the maximum values for icc 1 and icc 4 are obtained with the output open state.
is42s16400b1 issi ? integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 13 rev. a 12/09/03 ac electrical characteristics (1,2,3) -7 symbol parameter min. max. units t ck3 clock cycle time cas latency = 3 7 ? ns t ck2 cas latency = 2 10 ? ns t ac3 access time from clk (4) cas latency = 3 ? 6 ns t ac2 cas latency = 2 ? 9 ns t chi clk high level width 2.5 ? ns t cl clk low level width 2.5 ? ns t oh3 output data hold time cas latency = 3 2.8 ? ns t oh2 cas latency = 2 2.8 ? ns t lz output low impedance time 0 ? ns t hz3 output high impedance time (5) cas latency = 3 ? 6 ns t hz2 cas latency = 2 ? 9 ns t ds input data setup time 1.5 ? ns t dh input data hold time 0.8 ? ns t as address setup time 1.5 ? ns t ah address hold time 0.8 ? ns t cks cke setup time 1.5 ? ns t ckh cke hold time 0.8 ? ns t cka cke to clk recovery delay time 1clk+3 ?ns t cs command setup time ( cs , ras , cas , we , dqm) 2.0 ? ns t ch command hold time ( cs , ras , cas , we , dqm) 1 ? ns t rc command period (ref to ref / act to act) 63 ? ns t ras command period (act to pre) 37 50,000 ns t rp command period (pre to act) 16 ? ns t rcd active command to read / write command delay time 16 ? ns t rrd command period (act [0] to act[1]) 14 ? ns t dpl3 input data to precharge cas latency = 3 2clk ? ns command delay time t dpl2 cas latency = 2 2clk ? ns t dal3 input data to active / refresh cas latency = 3 2clk+t rp ?ns command delay time (during auto-precharge) t dal2 cas latency = 2 2clk+t rp ?ns t t transition time 1 10 ns t ref refresh cycle time (4096) ? 64 ms notes: 1. when power is first applied, memory operation should be started 100 s after v dd and v ddq reach their stipulated voltages. also note that the power-on sequence must be executed before starting memory operation. 2. measured with t t = 1 ns. 3. the reference level is 1.4 v when measuring input signal timing. rise and fall times are measured between v ih (min.) and v il (max.). 4. access time is measured at 1.4v with the load shown in the figure below. 5. the time t hz (max.) is defined as the time required for the output voltage to transition by 200 mv from v oh (min.) or v ol (max.) when the output is in the high impedance state.
is42s16400b1 issi ? 14 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 ac test conditions (input/output reference level: 1.5v) i/o 50 ? +1.5v 50 pf input load output load 2.8v 1.5v 0.2v clk input output t chi t ch t ac t oh t cs t ck t cl 2.8v 1.5v 1.5v 1.5v 0.2v operating frequency / latency relationships symbol parameter -7 units ? clock cycle time 7 ns ? operating frequency 133 mhz t ccd read/write command to read/write command 1 cycle t cked cke to clock disable or power-down entry mode 1 cycle t ped cke to clock enable or power-down exit setup mode 1 cycle t dqd dqm to input data delay 0 cycle t dqm dqm to data mask during writes 0 cycle t dqz dqm to data high-impedance during reads 2 cycle t dwd write command to input data delay 0 cycle t dal data-in to active command 5 cycle t dpl data-in to precharge command 2 cycle t bdl last data-in to burst stop command 1 cycle t cdl last data-in to new read/write command 1 cycle t rdl last data-in to precharge command 2 cycle t mrd load mode register command 2 cycle to active or refresh command t roh data-out to high-impedance from cl = 3 3 cycle precharge command cl = 2 2 cycle
is42s16400b1 issi ? integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 15 rev. a 12/09/03 functional description the 64mb sdrams (1 meg x 16 x 4 banks) are quad-bank drams which operate at 3.3v and include a synchronous interface (all signals are registered on the positive edge of the clock signal, clk). each of the 16,777,216-bit banks is organized as 4,096 rows by 256 columns by 16 bits. read and write accesses to the sdram are burst oriented; 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 active command which is then followed by a read or write command. the address bits registered coincident with the active command are used to select the bank and row to be accessed (ba0 and ba1 select the bank, a0-a11 select the row) . the address bits (a0-a7) registered coincident with the read or write command are used to select the starting column location for the burst access. prior to normal operation, the sdram must be initialized. the following sections provide detailed information covering device initialization, register definition, command descriptions and device operation. initialization sdrams must be powered up and initialized in a predefined manner. the 64m sdram is initialized after the power is applied to v dd and v ddq (simultaneously) and the clock is stable. a 100s delay is required prior to issuing any command other than a command inhibit or a nop . the command inhibit or nop may be applied during the 100us period and continue should at least through the end of the period. with at least one command inhibit or nop command having been applied, a precharge command should be applied once the 100s delay has been satisfied. all banks must be precharged. this will leave all banks in an idle state where two auto refresh cycles must be performed. after the auto refresh cycles are complete, the sdram is then ready for mode register programming. the mode register should be loaded prior to applying any operational command because it will power up in an unknown state.
is42s16400b1 issi ? 16 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 register definition mode register the mode register is used to define the specific mode of operation of the sdram. this definition includes the selection of a burst length, a burst type, a cas\ latency, an operating mode and a write burst mode, as shown in mode register definition. the mode register is programmed via the load mode register command and will retain the stored information until 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, m9 specifies the write burst mode, and m10 and m11 are reserved for future use. the mode register must be loaded when all banks are idle, and the controller must wait the specified time before initiating the subsequent operation. violating either of these requirements 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)
is42s16400b1 issi ? integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 17 rev. a 12/09/03 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 not supported page cn + 3, cn + 4... (y) (location 0-y) ?cn - 1, cn? burst length read and write accesses to the sdram are burst ori- ented, with the burst length being programmable, as shown in mode register definition. the burst length determines the maximum number of column loca- tions that can be accessed for a given read or write command. burst lengths 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-page burst is used in conjunction with the burst terminate command to generate arbitrary burst lengths. reserved states should not be used, as unknown opera- tion or incompatibility with future versions may result. when a read or write command is issued, a block of columns equal to the burst length is effectively selected. all accesses for that burst take place within this block, meaning that the burst will wrap within the block if a boundary is reached. the block is uniquely selected by a1-a7 (x16) when the burst length is set to two; by a2-a7 (x16) when the burst length is set to four; and by a3-a7 (x16) when the burst length is set to eight. the remaining (least significant) address bit(s) is (are) used to select the starting location within the block. full-page bursts wrap within the page if the boundary is reached. burst type accesses within a given burst may be programmed to be either sequential or interleaved; this is referred to as the burst type and is selected via bit m3. the ordering of accesses within a burst is determined by the burst length, the burst type and the starting column address, as shown in burst definition table.
is42s16400b1 issi ? 18 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 don't care undefined clk command dq read nop nop nop cas latency - 3 t ac t oh d out t0 t1 t2 t3 t4 t lz clk command dq read nop nop cas latency - 2 t ac t oh d out t0 t1 t2 t3 t lz cas latency cas latency the cas latency is the delay, in clock cycles, between the registration of a read command and the availability of the first piece of output data. the latency can be set to two or three clocks. if a read command is registered at clock edge n, and the latency is m clocks, the data will be available by clock edge n + m. the dqs will start driving as a result of the clock 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. for example, assuming that the clock cycle time is such that all relevant access times are met, if a read command is registered at t0 and the latency is programmed to two clocks, the dqs will start driving after t1 and the data will be valid by t2, as shown in cas latency diagrams. the allowable operating frequency table indicates the operating frequencies at which each cas latency setting can be used. reserved states should not be used as unknown operation or incompatibility with future versions may result. operating mode the normal operating mode is selected by setting m7 and m8 to zero; the other combinations of values for m7 and m8 are cas latency allowable operating frequency (mhz) speed cas latency = 2 cas latency = 3 7 100 133 reserved for future use and/or test modes. the programmed burst length applies to both read and write bursts. test modes and reserved states should not be used because unknown operation or incompatibility with future versions may result. write burst mode when m9 = 0, the burst length programmed via m0-m2 applies to both read and write bursts; when m9 = 1, the programmed burst length applies to read bursts, but write accesses are single-location (nonburst) accesses.
is42s16400b1 issi ? integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 19 rev. a 12/09/03 clk cke high - 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 t rcd t0 t1 t2 t3 t4 read or write operation bank/row activation before any read or write commands can be issued to a bank within the sdram, a row in that bank must be ?opened.? this is accomplished via the active command, which selects both the bank and the row to be activated (see activating specific row within specific bank ). after opening a row (issuing an active command) , a read or write command may be issued to that row, subject to the t rcd specification. minimum t rcd should be divided by the clock period and rounded up to the next whole number to determine the earliest clock edge after the active command on which a read or write command can be entered. for example, a t rcd specification of 20ns with a 125 mhz clock (8ns period) results in 2.5 clocks, rounded to 3. this is reflected in the following example, which covers any case where 2 < [t rcd (min)/t ck ] 3. (the same procedure is used to convert other specification limits from time units to clock cycles). a subsequent active command to a different row in the same bank can only be issued after the previous active row has been ?closed? (precharged). the minimum time interval between successive active commands to the same bank is defined by t rc . a subsequent active command to another bank can be issued while the first bank is being accessed, which results in a reduction of total row-access overhead. the minimum time interval between successive active com- mands to different banks is defined by t rrd . example: meeting t rcd (min) when 2 < < < < < [t rcd (min)/t ck ] 3
is42s16400b1 issi ? 20 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 clk cke high-z column address auto precharge no precharge cs ras cas we a0-a7 a10 ba0, ba1 bank address a8, a9, a11 read command reads read bursts are initiated with a read command, as shown in the read command diagram. the starting column and bank addresses are provided with the read command, and auto precharge is either enabled or disabled for that burst access. if auto precharge is enabled, the row being accessed is precharged at the completion of the burst. for the generic read commands used in the following illustrations, auto precharge is disabled. during read bursts, the valid data-out element from the starting column address will be available following the cas latency after the read command. each subsequent data-out element will be valid by the next positive clock edge. the cas latency diagram shows general timing for each possible cas latency setting. upon completion of a burst, assuming no other commands have been initiated, the dqs will go high-z. a full-page burst will continue until terminated. (at the end of the page, it will wrap to column 0 and continue.) data from any read burst may be truncated with a subsequent read command, and data from a fixed-length read burst may be immediately followed by data from a read command. in either case, a continuous flow of data can be maintained. the first data element from the new burst follows either the last element of a completed burst or the last desired data element of a longer burst which is being truncated. the new read command should be issued x cycles before the clock edge at which the last desired data element is valid, where x equals the cas latency minus one. this is shown in consecutive read bursts for cas latencies of two and three; data element n + 3 is either the last of a burst of four or the last desired of a longer burst. the 64mb sdram uses a pipelined architecture and therefore does not require the 2n rule associated with a prefetch architecture. a read command can be initiated on any clock cycle following a previous read command. full-speed random read accesses can be performed to the same bank, as shown in random read accesses, or each subsequent read may be performed to a different bank. data from any read burst may be truncated with a subsequent write command, and data from a fixed-length read burst may be immediately followed by data from a write command (subject to bus turnaround limitations). the write burst may be initiated on the clock edge immediately following the last (or last desired) data element from the read burst, provided that i/o contention can be avoided. in a given system design, there may be a possibility that the device driving the input data will go low-z before the sdram dqs go high-z. in this case, at least a single-cycle delay should occur between the last read data and the write command. the dqm input is used to avoid i/o contention, as shown in figures rw1 and rw2. the dqm signal must be asserted (high) at least two clocks prior to the write command (dqm latency is two clocks for output buffers) to suppress data-out from the read. once the write command is registered, the dqs will go high-z (or remain high-z), regardless of the state of the dqm signal, provided the dqm was active on the clock just prior to the write command that truncated the read command. if not, the second write will be an invalid write. for example, if dqm was low during t4 in figure rw2, then the writes at t5 and t7 would be valid, while the write at t6 would be invalid. the dqm signal must be de-asserted prior to the write command (dqm latency is zero clocks for input buffers) to ensure that the written data is not masked. figure rw1 shows the case where the clock frequency allows for bus contention to be avoided without adding a nop cycle, and figure rw2 shows the case where the additional nop is needed. a fixed-length read burst may be followed by, or truncated with, a precharge command to the same bank (provided that auto precharge was not activated) , and a full-page burst may be truncated with a precharge com mand to the
is42s16400b1 issi ? integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 21 rev. a 12/09/03 don't care undefined clk command dq read nop nop nop cas latency - 3 t ac t oh d out t0 t1 t2 t3 t4 t lz clk command dq read nop nop cas latency - 2 t ac t oh d out t0 t1 t2 t3 t lz cas latency same bank. the precharge command should be issued x cycles before the clock edge at which the last desired data element is valid, where x equals the cas latency minus one. this is shown in the read to precharge diagram for each possible cas latency; data element n + 3 is either the last of a burst of four or the last desired of a longer burst. following the precharge command, a subsequent command to the same bank cannot be issued until t rp 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 the optimum time (as described above) provides the same operation that would result from the same fixed-length burst with auto precharge. the disadvantage of the precharge command is that it requires that the com- mand and address buses be available at the appropriate time to issue the command; the advantage of the precharge command is that it can be used to truncate fixed-length or full-page bursts. full-page read bursts can be truncated with the burst terminate command, and fixed-length read bursts may be truncated with a burst terminate command, provided that auto precharge was not activated. the burst terminate command should be issued x cycles before the clock edge at which the last desired data element is valid, where x equals the cas latency minus one. this is shown in the read burst termination diagram for each possible cas latency; data element n + 3 is the last desired data element of a longer burst.
is42s16400b1 issi ? 22 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 don't care clk command address dq t0 t1 t2 t3 t4 t5 t6 read nop nop nop read nop nop d out n d out n+1 d out n+2 d out n+3 d out 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 d out n d out n+1 d out n+2 d out n+3 d out b bank, col n bank, col b cas latency - 3 x = 2 cycles consecutive read bursts
is42s16400b1 issi ? integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 23 rev. a 12/09/03 don't care clk command address dq t0 t1 t2 t3 t4 t5 read read read read nop nop d out n d out b d out m d out 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 d out n d out b d out m d out x bank, col n bank, col b cas latency - 3 bank, col m bank, col x random read accesses
is42s16400b1 issi ? 24 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 don't care clk dqm command address dq t0 t1 t2 t3 t4 read nop nop nop write d out n d in b bank, col n bank, col b t ds t hz 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 d out n d in b t ds t hz rw1 - read to write rw2 - read to write with extra clock cycle
is42s16400b1 issi ? integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 25 rev. a 12/09/03 don't care clk command address dq t0 t1 t2 t3 t4 t5 t6 t7 read nop nop nop nop nop active d out n d out n+1 d out n+2 d out n+3 bank a, col n bank a, row bank (a or all) cas latency - 2 x = 1 cycle t rp precharge don't care clk command address dq t0 t1 t2 t3 t4 t5 t6 t7 read nop nop nop nop nop active d out n d out n+1 d out n+2 d out n+3 bank, col n bank, col b cas latency - 3 x = 2 cycles t rp bank a, row precharge read to precharge
is42s16400b1 issi ? 26 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 don't care clk command address dq t0 t1 t2 t3 t4 t5 t6 read nop nop nop nop nop d out n d out n+1 d out n+2 d out n+3 bank a, col n cas latency - 2 x = 1 cycle burst terminate don't care clk command address dq t0 t1 t2 t3 t4 t5 t6 t7 read nop nop nop nop nop nop d out n d out n+1 d out n+2 d out n+3 bank, col n cas latency - 3 x = 2 cycles burst terminate read burst termination
is42s16400b1 issi ? integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 27 rev. a 12/09/03 clk cke high - z column address auto precharge bank address cs ras cas we a0-a7 a10 ba0, ba1 no precharge a8, a9, a11 write command the starting column and bank addresses are provided with the write command, and auto precharge is either enabled or disabled for that access. if auto precharge is enabled, the row being accessed is precharged at the completion of the burst. for the generic write commands used in the following illustrations, auto precharge is disabled. during write bursts, the first valid data-in element will be registered coincident with the write command. subsequent data elements will be registered on each successive positive clock edge. upon completion of a fixed-length burst, assuming no other commands have been initiated, the dqs will remain high-z and any additional input data will be ignored (see write burst). a full-page burst will continue until terminated. (at the end of the page, it will wrap to column 0 and continue.) data for any write burst may be truncated with a subsequent write command, and data for a fixed-length write burst may be immediately followed by data for a write command. the new write command can be issued on any clock following the previous write command, and the data provided coincident with the new command applies to the new command. an example is shown in write to write diagram. data n + 1 is either the last of a burst of two or the last desired of a longer burst. the 64mb sdram uses a pipelined architec- ture and therefore does not require the 2n rule associated with a prefetch architecture. a write command can be initiated on any clock cycle following a previous write command. full-speed random write accesses within a page can be performed to the same bank, as shown in random write cycles, or each subsequent write may be per- formed to a different bank. data for any write burst may be truncated with a subse- quent read command, and data for a fixed-length write burst may be immediately followed by a subsequent read command. once the read command is registered, the data inputs will be ignored, and writes will not be ex- ecuted. an example is shown in write to read. data n + 1 is either the last of a burst of two or the last desired of a longer burst. data for a fixed-length write burst may be followed by, or truncated with, a precharge command to the same bank (provided that auto precharge was not activated), and a full- page write burst may be truncated with a precharge command to the same bank. the precharge command should be issued t wr after the clock edge at which the last desired input data element is registered. the auto precharge mode requires a t wr of at least one clock plus time, regardless of frequency. in addition, when truncating a write burst, the dqm signal must be used to mask input data for the clock edge prior to, and the clock edge coincident with, the precharge command. an example is shown in the write to precharge diagram. data n +1 is either the last of a burst of two or the last desired of a longer burst. following the precharge command, a subsequent com- mand to the same bank cannot be issued until t rp is met. in the case of a fixed-length burst being executed to comple- tion, a precharge command issued at the optimum time (as described above) provides the same operation that would result from the same fixed-length burst with auto precharge. the disadvantage of the precharge command is that it requires that the command and address buses be available at the appropriate time to issue the command; the advantage of the precharge command is that it can be used to truncate fixed-length or full-page bursts. fixed-length or full-page write bursts can be truncated with the burst terminate command. when truncating a write burst, the input data applied coincident with the burst terminate command will be ignored. the last data written (provided that dqm is low at that time) will be the input data applied one clock previous to the burst terminate command. this is shown in write burst termination, where data n is the last desired data element of a longer burst. writes write bursts are initiated with a write command, as shown in write command diagram.
is42s16400b1 issi ? 28 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 clk command address dq t0 t1 t2 t3 write nop nop nop d in n d in n+1 bank, col n don't care clk command address dq t0 t1 t2 write nop write d in n d in n+1 d in 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 d in n d in b d in m d in x bank, col n bank, col b bank, col m bank, col x random write cycles
is42s16400b1 issi ? integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 29 rev. a 12/09/03 don't care clk dqm command address dq t0 t1 t2 t3 t4 t5 t6 write nop nop nop act ive nop bank a, col n bank a, row bank (a or all) t wr t rp precharge d in n d in n+1 write to precharge (t wr @ t ck 15ns) don't care clk command address dq t0 t1 t2 t3 t4 t5 write nop read nop nop nop d in n d in n+1 d out b d out b+1 bank, col n bank, col b write to read
is42s16400b1 issi ? 30 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 don't care clk dqm command address dq t0 t1 t2 t3 t4 t5 t6 write nop nop nop act ive nop bank a, col n bank a, row bank (a or all) t wr t rp precharge d in n d in n+1 write to precharge (t wr @ t ck < 15ns) clk command address dq t0 t1 t2 write d in n ( data ) bank, col n don't care (address) burst terminate next command write burst termination
is42s16400b1 issi ? integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 31 rev. a 12/09/03 clk cke high - 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 t cks t cks all banks idle enter power-down mode exit power-down mode t rcd t ras t rc input buffers gated off precharge command power-down power-down power-down occurs if cke is registered low coincident with a nop or command inhibit when no accesses are in progress. if power-down occurs when all banks are idle, this mode is referred to as precharge power-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 output buffers, excluding cke, for maximum power savings while in standby. the device may not remain in the power- down state longer than the refresh period (64ms) since no refresh operations are performed in this mode. the power-down state is exited by registering a nop or command inhibit and cke high at the desired clock edge (meeting t cks ). see figure below. precharge the precharge command (see figure) is used to deactivate the open row in a particular bank or the open row in all banks. the bank(s) will be available for a subsequent row access some specified time (t rp ) after the precharge command is issued. input a10 deter- mines whether one or all banks are to be precharged, and in the case where only one bank is to be precharged, inputs ba0, ba1 select the bank. when all banks are to be precharged, inputs ba0, ba1 are treated as ?don?t care.? once a bank has been precharged, it is in the idle state and must be activated prior to any read or write com- mands being issued to that bank.
is42s16400b1 issi ? 32 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 don't care clk cke command address dq t0 t1 t2 t3 t4 t5 nop write nop nop bank a, col n d in n d in n+1 d in n+2 internal clock 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 d in n d in n+1 d in n+2 d in n+3 internal clock clock suspend clock suspend mode occurs when a column access/burst is in progress and cke is registered low. in the clock suspend mode, the internal clock is deactivated, ?freezing? the synchronous logic. for each positive clock edge on which cke is sampled low, the next internal positive clock edge is suspended. any command or data present on the input pins at the time of a suspended internal clock edge is ignored; any data present on the dq pins remains driven; and burst counters are not incremented, as long as the clock is suspended. (see following examples.) clock suspend mode is exited by registering cke high; the internal clock and related operation will resume on the subsequent positive clock edge. clock suspend during write burst clock suspend during write burst
is42s16400b1 issi ? integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 33 rev. a 12/09/03 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 d out a d out a+1 d out b d out b+1 bank n, col a bank m, col b cas latency - 3 (bank n) cas latency - 3 (bank m) t rp - bank n t r p - bank m read - ap bank n read - ap bank 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 d out a d in b d in b+1 d in b+2 d in b+3 bank n, col a bank m, col b cas latency - 3 (bank n) t rp - bank n t r p - bank m write - ap bank n write - ap bank 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 write the burst read/single write mode is entered by programming the 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 the programmed burst length. read commands access columns according to the programmed burst length and sequence, just as in the normal mode of operation (m9 = 0). concurrent auto precharge an access command (read or write) to another bank while an access command with auto precharge enabled is executing is not allowed by sdrams, unless the sdram supports concurrent auto precharge. issi sdrams support concurrent auto precharge. four cases where concurrent auto precharge occurs are defined below. read with auto precharge 1. interrupted by a read (with or without auto precharge): a read to bank m will interrupt a read on bank n, cas latency later. the precharge to bank n will begin when the read to bank m is registered. 2. interrupted by a write (with or without auto precharge): a write to bank m will interrupt a read on bank n when registered. dqm should be used two clocks prior to the write command to prevent bus contention. the precharge to bank n will begin when the write to bank 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
is42s16400b1 issi ? 34 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 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 d in a d in a+1 d out b d out b+1 bank n, col a bank m, col b cas latency - 3 (bank m) t rp - bank n t r p - bank m write - ap bank n read - ap bank m page active write with burst of 4 interrupt burst, write-back precharge page active read with burst of 4 precharge internal states t wr - 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 t rp - bank n t r p - bank m write - ap bank n write - ap bank m page active write with burst of 4 interrupt burst, write-back precharge page active write with burst of 4 write-back internal states t wr - bank n d in a d in a+1 d in a+2 d in b d in b+1 d in b+2 d in b+3 write with auto precharge 3. interrupted by a read (with or without auto precharge): a read to bank m will interrupt a write on bank n when registered, with the data-out appearing cas latency later. the precharge to bank n will begin after t wr is met, where t wr begins when the read to bank m is registered. the last valid write to bank n will be data-in registered one clock prior to the read to bank m. 4. interrupted by a write (with or without auto precharge): a write to bank m will interrupt a write on bank n when registered. the precharge to bank n will begin after t wr is met, where t wr begins when the write to bank m is registered. the last valid data write to bank n will be data registered one clock prior to a write to bank m. fig cap 3 - write with auto precharge interrupted by a read fig cap 4 - write with auto precharge interrupted by a write
is42s16400b1 issi ? integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 35 rev. a 12/09/03 initialize and load mode register don't care clk cke command dqm/ dqml, dqmh a0-a9, a11 a10 ba0, ba1 dq t ch t cl t ck t cmh t cms t cmh t cms t cmh t cms t cks t ckh t0 t1 tn+1 to+1 tp+1 tp+2 tp+3 t mrd t rfc t rfc t rp row row bank t as t ah t as t ah code code all banks single bank all banks auto refresh auto refresh load mode register t = 100s min. power-up: vdd and clk stable precharge all banks auto refresh auto refresh program mode register nop precharge nop nop nop active t (2, 3, 4)
is42s16400b1 issi ? 36 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 power-down mode cycle cas latency = 2, 3 don't care clk cke command dqm/ dqml, dqmh a0-a9, a11 a10 ba0, ba1 dq t as t ah bank t ch t cl t ck t cms t cmh t cks t ckh precharge nop nop nop active all banks single bank row row bank t cks t cks precharge all active banks all banks idle two clock cycles input buffers gated off while in power-down mode all banks idle, enter power-down mode exit power-down mode t0 t1 t2 tn+1 tn+2 high-z
is42s16400b1 issi ? integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 37 rev. a 12/09/03 clock suspend mode cas latency = 2, burst length = 2 don't care clk cke command dqm/ dqml, dqmh a0-a9, a11 a10 ba0, ba1 dq t cms t cmh t as t ah t as t ah t as t ah t ch t cl t ck t cms t cmh t cks t ckh column m (2) t0 t1 t2 t3 t4 t5 t6 t7 t8 t9 read nop nop nop nop nop write nop t cks t ckh bank bank column n (2) t ac t ac t oh t hz d out m d out m+1 t lz undefined d out e+1 t ds t dh d out e
is42s16400b1 issi ? 38 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 auto-refresh cycle cas latency = 2, 3 t rp t rfc t rfc don't care clk cke command dqm/ dqml, dqmh a0-a9, a11 a10 ba0, ba1 dq t as t ah t ch t cl t ck t cms t cmh t cks t ckh t0 t1 t2 tn+1 to+1 all banks single bank bank (s) row row bank high-z precharge nop nop nop active auto refresh auto refresh
is42s16400b1 issi ? integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 39 rev. a 12/09/03 self-refresh cycle cas latency = 2, 3 clk cke command dqm/ dqml, dqmh a0-a9, a11 a10 ba0, ba1 dq t as t ah bank t cl t ch t ck t cms t cmh t cks t ckh all banks single bank t cks precharge all active banks clk stable prior to exiting self refresh mode enter self refresh mode exit self refresh mode (restart refresh time base) t0 t1 t2 tn+1 to+1 to+2 high-z auto refresh auto refresh precharge nop nop nop t cks t ras t rp t xsr don't care
is42s16400b1 issi ? 40 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 read without auto precharge don't care undefined clk cke command dqm/ dqml, dqmh a0-a9, a11 a10 ba0, ba1 dq t cms t cmh active nop read nop nop nop precharge nop active t as t ah t as t ah t as t ah row row bank column m (2) t ch t cl t ck t cms t cmh t cks t ckh bank t rcd cas latency t ac t ac t ac t ac t oh t hz t oh d out m t oh d out m+1 t oh d out m+2 d out m+3 t0 t1 t2 t3 t4 t5 t6 t7 t8 disable auto precharge row row bank t lz t ras t rc t rp all banks single bank bank
is42s16400b1 issi ? integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 41 rev. a 12/09/03 read with auto precharge don't care undefined clk cke command dqm/ dqml, dqmh a0-a9, a11 a10 ba0, ba1 dq t cms t cmh active nop read nop nop nop nop nop active t as t ah t as t ah t as t ah row row bank column m (2) t ch t cl t ck t cms t cmh t cks t ckh bank t rcd t ras t rc cas latency t ac t ac t ac t ac t oh t hz t oh d out m t oh d out m+1 t oh d out m+2 d out m+3 t0 t1 t2 t3 t4 t5 t6 t7 t8 t rp enable auto precharge row row bank t lz
is42s16400b1 issi ? 42 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 single read without auto precharge don't care undefined clk cke command dqm/ dqml, dqmh a0-a9, a11 a10 ba0, ba1 dq t cms t cmh active nop read nop nop precharge nop active nop t as t ah t as t ah t as t ah row row bank column m (2) t ch t cl t ck t cms t cmh t cks t ckh bank t rcd t ras t rc cas latency t ac t hz t oh d out m t0 t1 t2 t3 t4 t5 t6 t7 t8 t rp disable auto precharge row row bank t lz all banks single bank bank
is42s16400b1 issi ? integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 43 rev. a 12/09/03 single read with auto precharge don't care undefined clk cke command dqm/ dqml, dqmh a0-a9, a11 a10 ba0, ba1 dq t cms t cmh active nop nop nop read nop nop active nop t as t ah t as t ah t as t ah row row bank column m (2) t ch t cl t ck t cms t cmh t cks t ckh bank t rcd t ras t rc cas latency t ac t hz t oh d out m t0 t1 t2 t3 t4 t5 t6 t7 t8 t rp enable auto precharge row row bank
is42s16400b1 issi ? 44 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 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 t cms t cmh t as t ah t as t ah t as t ah t rcd - bank 0 cas latency - bank 0 t rcd - bank 0 t ras - bank 0 t rc - bank 0 t ch t cl t ck t cms t cmh t cks t ckh active nop read nop active nop read nop active row row bank 0 row row t rrd t rcd - bank 3 t rp - 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 t ac t oh t oh t oh t oh t oh d out m d out m+ 1 d out m+ 2 d out m+ 3 d out b t ac t ac t ac t ac t ac t lz cas latency - bank 3
is42s16400b1 issi ? integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 45 rev. a 12/09/03 read - full-page burst don't care undefined clk cke command dqm/ dqml, dqmh a0-a9, a11 a10 ba0, ba1 dq t cms t cmh active nop read nop nop nop nop nop burst term nop nop t as t ah t as t ah t as t ah row row bank column m (2) t ch t cl t ck t cms t cmh t cks t ckh bank t rcd cas latency t ac t ac t ac t ac t ac t hz t lz t ac t oh t oh t oh t oh t oh t oh d out m d out m+ 1 d out m+ 2 d out m- 1 d out m d out m+ 1 each row (x4) has 1,024 locations full page completion 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
is42s16400b1 issi ? 46 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 read - dqm operation don't care undefined clk cke command dqm/ dqml, dqmh a0-a9, a11 a10 ba0, ba1 dq t cms t cmh active nop read nop nop nop nop nop nop t as t ah t as t ah t as t ah enable auto precharge disable auto precharge row row bank t rcd cas latency d out m d out m+ 2 d out m+ 3 column m (2) bank t ch t cl t ck t cms t cmh t cks t ckh t oh t oh t oh t ac t ac t ac t hz t hz t lz t lz t0 t1 t2 t3 t4 t5 t6 t7 t8
is42s16400b1 issi ? integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 47 rev. a 12/09/03 write - without auto precharge don't care clk cke command dqm/ dqml, dqmh a0-a9, a11 a10 ba0, ba1 dq t cms t cmh t as t ah t as t ah t as t ah t rcd t ras t rc t ch t cl t ck t cms t cmh t cks t ckh active nop write nop nop nop precharge nop active t wr (2) t rp column m (3) row disable auto precharge row row row bank t ds t dh t ds t dh t ds t dh t ds t dh d in m d in m+ 1 d in m+ 2 d in m+ 3 bank bank bank all banks single bank t0 t1 t2 t3 t4 t5 t6 t7 t8
is42s16400b1 issi ? 48 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 write - with auto precharge don't care clk cke command dqm/ dqml, dqmh a0-a9, a11 a10 ba0, ba1 dq t cms t cmh t as t ah t as t ah t as t ah t rcd t ras t rc t ch t cl t ck t cms t cmh t cks t ckh active nop write nop nop nop nop nop nop active t wr t rp column m (2) row bank bank enable auto precharge row row row bank t ds t dh t ds t dh t ds t dh t ds t dh d in m d in m+ 1 d in m+ 2 d in m+ 3 t0 t1 t2 t3 t4 t5 t6 t7 t8 t9
is42s16400b1 issi ? integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 49 rev. a 12/09/03 single write - without auto precharge don't care clk cke command dqm/ dqml, dqmh a0-a9, a11 a10 ba0, ba1 dq t cms t cmh t as t ah t as t ah t as t ah t ds t dh t rcd t ras t rc t ch t cl t ck t cms t cmh t cks t ckh active nop write nop (4) nop (4) precharge nop active nop t wr (3) t rp disable auto precharge row row row bank d in m column m (3) row bank bank bank all banks single bank t0 t1 t2 t3 t4 t5 t6 t7 t8
is42s16400b1 issi ? 50 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 single write - with auto precharge don't care clk cke command dqm/ dqml, dqmh a0-a9, a11 a10 ba0, ba1 dq t cms t cmh t as t ah t as t ah t as t ah t ds t dh t rcd t ras t rc t ch t cl t ck t cms t cmh t cks t ckh active nop (3) nop (3) nop (3) write nop nop nop active nop t wr t rp column m (2) row bank bank enable auto precharge row row row bank d in m t0 t1 t2 t3 t4 t5 t6 t7 t8 t9
is42s16400b1 issi ? integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 51 rev. a 12/09/03 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 t cms t cmh t as t ah t as t ah t as t ah t ds t dh t ds t dh t ds t dh t rcd - bank 0 t rcd - bank 0 t wr - bank 1 t ras - bank 0 t rc - bank 0 t ch t cl t ck t ds t dh t ds t dh t ds t dh t ds t dh t ds t dh t cms t cmh t cks t ckh active nop write nop active nop write nop nop active d in m d in m+ 1 d in m+ 2 d in m+ 3 d in b d in b+ 1 d in b+ 2 d in b+ 3 row row bank 0 row row t rrd t rcd - bank 1 t wr - bank 0 t rp - 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
is42s16400b1 issi ? 52 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 don't care clk cke command dqm/ dqml, dqmh a0-a9, a11 a10 ba0, ba1 dq t cms t cmh active nop write nop nop nop nop burst term nop t as t ah t as t ah t as t ah t ds t dh t ds t dh t ds t dh row row bank t rcd d in m d in m+ 1 d in m+ 2 d in m+ 3 d in m- 1 column m (2) t ch t cl t ck t ds t dh t ds t dh t ds t dh t cms t cmh t cks t ckh bank full page completed t0 t1 t2 t3 t4 t5 tn+1 tn+2 write - full page burst
is42s16400b1 issi ? integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 53 rev. a 12/09/03 don't care clk cke command dqm/ dqml, dqmh a0-a9, a11 a10 ba0, ba1 dq t cms t cmh active nop write nop nop nop nop nop t as t ah t as t ah t as t ah t ds t dh t ds t dh t ds t dh enable auto precharge disable auto precharge row row bank t rcd d in m d in m+ 2 d in m+ 3 column m (2) bank t ch t cl t ck t cms t cmh t cks t ckh t0 t1 t2 t3 t4 t5 t6 t7 write - dqm operation
is42s16400b1 issi ? 54 integrated silicon solution, inc. ? www.issi.com ? 1-800-379-4774 rev. a 12/09/03 ordering information commercial range: 0 c to 70 c frequency speed (ns) order part no. package 133 mhz 7 IS42S16400B1-7T 400-mil tsop ii
packaging information issi ? integrated silicon solution, inc. ? 1-800-379-4774 1 rev. c 01/28/02 plastic tsop 54?pin, 86-pin package code: t (type ii) plastic tsop (t - type ii) millimeters inches symbol min max min max ref. std. no. leads (n) 54 a ? 1.20 ? 0.047 a1 0.05 0.15 0.002 0.006 a2 ? ? ? ? b 0.30 0.45 0.012 0.018 c 0.12 0.21 0.005 0.0083 d 22.02 22.42 0.867 0.8827 e1 10.03 10.29 0.395 0.405 e 11.56 11.96 0.455 0.471 e 0.80 bsc 0.031 bsc l 0.40 0.60 0.016 0.024 l1 ? ? ? ? zd 0.71 ref 0 8 0 8 d seating plane b e c 1 n/2 n/2+1 n e1 a1 a e l 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 be measured from the bottom of the package . 4. formed leads shall be planar with respect to one another within 0.004 inches at the seating plane. plastic tsop (t - type ii) millimeters inches symbol min max min max ref. std. no. leads (n) 86 a ? 1.20 ? 0.047 a1 0.05 0.15 0.002 0.006 a2 0.95 1.05 0.037 0.041 b 0.17 0.27 0.007 0.011 c 0.12 0.21 0.005 0.008 d 22.02 22.42 0.867 0.8827 e1 10.16 bsc 0.400 bsc e 11.56 11.96 0.455 0.471 e 0.50 bsc 0.020 bsc l 0.40 0.60 0.016 0.024 l1 0.80 ref 0.031 ref zd 0.61 ref 0.024 bsc 0 8 0 8

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