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1 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. 16 meg x 4 8 meg x 8 4 meg x 16 configuration 4 meg x 4 x 4 banks 2 meg x 8 x 4 banks 1 meg x 16 x 4 banks refresh count 4k 4k 4k row addressing 4k (a0-a11) 4k (a0-a11) 4k (a0-a11) bank addressing 4 (ba0, ba1) 4 (ba0, ba1) 4 (ba0, ba1) column addressing 1k (a0-a9) 512 (a0-a8) 256 (a0-a7) synchronous dram mt48lc16m4a2 - 4 meg x 4 x 4 banks mt48lc8m8a2 - 2 meg x 8 x 4 banks mt48lc4m16a2 - 1 meg x 16 x 4 banks for the latest data sheet, please refer to the micron web site: www.micron.com/mti/msp/html/datasheet.html pin assignment (top view) 54-pin tsop features ? pc66-, pc100- and pc133-compliant ? 143 mhz, graphical 4 meg x 16 option ? fully synchronous; all signals registered on positive edge of system clock ? internal pipelined operation; column address can be changed every clock cycle ? internal banks for hiding row access/precharge ? programmable burst lengths: 1, 2, 4, 8 or full page ? auto precharge, includes concurrent auto precharge, and auto refresh modes ? self refresh modes: standard and low power ? 64ms, 4,096-cycle refresh ? lvttl-compatible inputs and outputs ? single +3.3v 0.3v power supply options marking ? configurations 16 meg x 4 (4 meg x 4 x 4 banks) 16m4 8 meg x 8 (2 meg x 8 x 4 banks) 8m8 4 meg x 16 (1 meg x 16 x 4 banks) 4m16 ? write recovery ( t wr) t wr = 2 clk 1 a2 ? plastic package - ocpl 2 54-pin tsop ii (400 mil) tg ? timing (cycle time) 10ns @ cl2 (pc100) -8e 7.5ns @ cl3 (pc133) -75 7.5ns @ cl2 (pc133) -7e 7ns @ cl3 (143 mhz) -7g 3 ? self refresh standard none low power l ? operating temperature range commercial (0c to +70c) none extended (-40c to +85c) it 4 part number example: mt48lc8m8a2tg-8e note : 1. refer to micron technical note tn-48-05. 2. off-center parting line. 3. available on 4 meg x 16. 4. available on x8, x16, -8e. v dd dq0 v dd q dq1 dq2 vssq dq3 dq4 v dd q dq5 dq6 vssq dq7 v dd dqml we# cas# ras# cs# ba0 ba1 a10 a0 a1 a2 a3 v dd 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 vss dq15 vssq dq14 dq13 v dd q dq12 dq11 vssq dq10 dq9 v dd q dq8 vss nc dqmh clk cke nc a11 a9 a8 a7 a6 a5 a4 vss x8 x16 x16 x8 x4 x4 - dq0 - nc dq1 - nc dq2 - nc dq3 - nc - nc - - - - - - - - - - - - - nc - nc dq0 - nc nc - nc dq1 - nc - nc - - - - - - - - - - - - - dq7 - nc dq6 - nc dq5 - nc dq4 - nc - - dqm - - - - - - - - - - - - nc - nc dq3 - nc nc - nc dq2 - nc - - dqm - - - - - - - - - - - note: the # symbol indicates signal is active low. a dash (C) indicates x8 and x4 pin function is same as x16 pin function. key timing parameters speed clock access time setup hold grade frequency cl = 2* cl = 3* time time -7g 143 mhz C 6ns 2ns 1ns -7e 143 mhz C 5.4ns 1.5ns 0.8ns -75 133 mhz C 5.4ns 1.5ns 0.8ns -8e 125 mhz C 6ns 2ns 1ns -7e 133 mhz 5.4ns C 1.5ns 0.8ns -75 100 mhz 6ns C 1.5ns 0.8ns -8e 100 mhz 6ns C 2ns 1ns * cl = cas (read) latency
2 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. command are used to select the starting column loca- tion for the burst access. the sdram provides for programmable read or write burst lengths of 1, 2, 4 or 8 locations, or the full page, with a burst terminate option. an auto precharge function may be enabled to provide a self- timed row precharge that is initiated at the end of the burst sequence. the 64mb sdram uses an internal pipelined architecture to achieve high-speed operation. this architecture is compatible with the 2 n rule of prefetch architectures, but it also allows the column address to be changed on every clock cycle to achieve a high- speed, fully random access. precharging one bank while accessing one of the other three banks will hide the precharge cycles and provide seamless, high-speed, random-access operation. the 64mb sdram is designed to operate in 3.3v memory systems. an auto refresh mode is provided, along with a power-saving, power-down mode. all inputs and outputs are lvttl-compatible. sdrams offer substantial advances in dram oper- ating performance, including the ability to synchro- nously burst data at a high data rate with automatic column-address generation, the ability to interleave between internal banks in order to hide precharge time and the capability to randomly change column addresses on each clock cycle during a burst access. general description the 64mb sdram is a high-speed cmos, dynamic random-access memory containing 67,108,864 bits. it is internally configured as a quad-bank dram with a synchronous interface (all signals are registered on the positive edge of the clock signal, clk). each of the x4s 16,777,216-bit banks is organized as 4,096 rows by 1,024 columns by 4 bits. each of the x8s 16,777,216-bit banks is organized as 4,096 rows by 512 columns by 8 bits. each of the x16s 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 con- tinue 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, ba1 select the bank; a0-a11 select the row). the address bits registered coincident with the read or write 64mb sdram part numbers part number architecture MT48LC16M4A2TG 16 meg x 4 mt48lc8m8a2tg 8 meg x 8 mt48lc4m16a2tg 4 meg x 16
3 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. table of contents functional block diagram - 16 meg x 4 ................. 4 functional block diagram - 8 meg x 8 ................. 5 functional block diagram - 4 meg x 16 ............... 6 pin descriptions ..................................................... 7 functional description ......................................... 8 initialization ...................................................... 8 register definition ............................................ 8 mode register ............................................... 8 burst length ............................................ 8 burst type ............................................... 9 cas latency ............................................ 10 operating mode ...................................... 10 write burst mode .................................... 10 commands ........................................................ 11 truth table 1 (commands and dqm operation) ....... 11 command inhibit ........................................ 12 no operation (nop) .................................... 12 load mode register ...................................... 12 active ............................................................ 12 read .............................................................. 12 write ............................................................. 12 precharge ...................................................... 12 auto precharge ............................................. 12 burst terminate ............................................ 12 auto refresh ................................................. 13 self refresh ................................................... 13 operation .......................................................... 14 bank/row activation ................................... 14 reads ............................................................ 15 writes ........................................................... 21 precharge ...................................................... 23 power-down ................................................. 23 clock suspend .............................................. 24 burst read/single write ............................... 24 concurrent auto precharge ......................... 25 truth table 2 (cke) ................................................. 27 truth table 3 (current state, same bank) .................. 28 truth table 4 (current state, different bank) ............. 30 absolute maximum ratings ................................... 32 dc electrical characteristics and operating conditions ................................... 32 i dd specifications and conditions ......................... 32 capacitance ............................................................ 33 electrical characteristics and recommended operating conditions (timing table) ............. 33 timing waveforms initialize and load mode register ..................... 36 power-down mode ............................................ 37 clock suspend mode ......................................... 38 auto refresh mode ............................................ 39 self refresh mode .............................................. 40 reads read - without auto precharge ................... 41 read - with auto precharge ......................... 42 single read - without auto precharge ........ 43 single read - with auto precharge .............. 44 alternating bank read accesses ................... 45 read - full-page burst ................................... 46 read - dqm operation ................................ 47 writes write - without auto precharge .................. 48 write - with auto precharge ....................... 49 single write - without auto precharge ....... 50 single write - with auto precharge ............. 51 alternating bank write accesses ................. 52 write - full-page burst ................................. 53 write - dqm operation ............................... 54
4 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. functional block diagram 16 meg x 4 sdram 12 ras# cas# row- address mux clk cs# we# cke control logic column- address counter/ latch mode register 10 command decode a0-a11, ba0, ba1 dqm 12 address register 14 1024 (x4) 4096 i/o gating dqm mask logic read data latch write drivers column decoder bank0 memory array (4,096 x 1,024 x 4) bank0 row- address latch & decoder 4096 sense amplifiers bank control logic dq0-dq3 4 4 data input register data output register 4 12 bank1 bank2 bank3 12 10 2 1 1 2 refresh counter
5 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. functional block diagram 8 meg x 8 sdram 12 ras# cas# row- address mux clk cs# we# cke control logic column- address counter/ latch mode register 9 command decode a0-a11, ba0, ba1 dqm 12 address register 14 512 (x8) 4096 i/o gating dqm mask logic read data latch write drivers column decoder bank0 memory array (4,096 x 512 x 8) bank0 row- address latch & decoder 4096 sense amplifiers bank control logic dq0-dq7 8 8 data input register data output register 8 12 bank1 bank2 bank3 12 9 2 1 1 2 refresh counter
6 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. 12 ras# cas# row- address mux clk cs# we# cke column- address counter/ latch 8 a0-a11, ba0, ba1 dqml, dqmh 12 address register 14 256 (x16) 4096 i/o gating dqm mask logic read data latch write drivers column decoder bank0 memory array (4,096 x 256 x 16) bank0 row- address latch & decoder 4096 sense amplifiers bank control logic dq0-dq15 16 16 data input register data output register 16 12 bank1 bank2 bank3 12 8 2 2 2 2 refresh counter control logic mode register command decode functional block diagram 4 meg x 16 sdram
7 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. pin descriptions pin numbers symbol type description 38 clk input clock: clk is driven by the system clock. all sdram input signals are sampled on the positive edge of clk. clk also increments the internal burst counter and controls the output registers. 37 cke input clock enable: cke activates (high) and deactivates (low) the clk signal. deactivating the clock provides precharge power-down and self refresh operation (all banks idle), active power-down (row active in any bank) or clock suspend operation (burst/access in progress). cke is synchronous except after the device enters power- down and self refresh modes, where cke becomes asynchronous until after exiting the same mode. the input buffers, including clk, are disabled during power-down and self refresh modes, providing low standby power. cke may be tied high. 19 cs# input chip select: cs# enables (registered low) and disables (registered high) the command decoder. all commands are masked when cs# is registered high. cs# provides for external bank selection on systems with multiple banks. cs# is considered part of the command code. 16, 17, 18 we#, cas#, input command inputs: we#, cas# and ras# (along with cs#) define the ras# command being entered. 39 x4, x8: dqm input input/output mask: dqm is an input mask signal for write accesses and an output enable signal for read accesses. input data is masked when 15, 39 x16: dqml, dqm is sampled high during a write cycle. the output buffers are dqmh placed in a high-z state (two-clock latency) when dqm is sampled high during a read cycle. on the x4 and x8, dqml (pin 15) is a nc and dqmh is dqm. on the x16, dqml corresponds to dq0-dq7 and dqmh corresponds to dq8-dq15. dqml and dqmh are considered same state when referenced as dqm. 20, 21 ba0, ba1 input bank address inputs: ba0 and ba1 define to which bank the active, read, write or precharge command is being applied. 23-26, 29-34, 22, 35 a0-a11 input address inputs: a0-a11 are sampled during the active command (row- address a0-a11) and read/write command (column-address a0-a9 [x4]; a0-a8 [x8]; a0-a7 [x16]; 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. 2, 4, 5, 7, 8, 10, 11, 13, 42, dq0-dq15 x16: i/o data input/output: data bus for x16 (4, 7, 10, 13, 42, 45, 48, 51 are 44, 45, 47, 48, 50, 51, 53 ncs for x8; and 2, 4, 7, 8, 10, 13, 42, 45, 47, 48, 51, 53 are ncs for x4). 2, 5, 8, 11, 44, 47, 50, 53 dq0-dq7 x8: i/o data input/output: data bus for x8 (2, 8, 47, 53 are ncs for x4). 5, 11, 44, 50 dq0-dq3 x4: i/o data input/output: data bus for x4. 36, 40 nc C no connect: these pins should be left unconnected. 3, 9, 43, 49 v dd q supply dq power: isolated dq power on the die for improved noise immunity. 6, 12, 46, 52 v ss q supply dq ground: isolated dq ground on the die for improved noise immunity. 1, 14, 27 v dd supply power supply: +3.3v 0.3v. 28, 41, 54 v ss supply ground.
8 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. functional description in general, the 64mb sdrams (4 meg x 4 x 4 banks, 2 meg x 8 x 4 banks and 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 x4s 16,777,216-bit banks is organized as 4,096 rows by 1,024 columns by 4 bits. each of the x8s 16,777,216-bit banks is organized as 4,096 rows by 512 columns by 8 bits. each of the x16s 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 con- tinue for a programmed number of locations in a programmed sequence. accesses begin with the regis- tration of an active command which is then followed by a read or write command. the address bits regis- tered 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 (x4: a0-a9; x8: a0-a8; x16: a0-a7) registered coinci- dent 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 defi- nition, command descriptions and device operation. initialization sdrams must be powered up and initialized in a predefined manner. operational procedures other than those specified may result in undefined operation. once power is applied to v dd and v dd q (simulta- neously) and the clock is stable (stable clock is defined as a signal cycling within timing constraints specified for the clock pin), the sdram requires a 100s delay prior to issuing any command other than a com- mand inhibit or a nop. starting at some point during this 100s period and continuing at least through the end of this period, command inhibit or nop com- mands should be applied. once the 100s delay has been satisfied with at least one command inhibit or nop command having been applied, a precharge command should be ap- plied. all banks must be precharged, thereby placing the device in the all banks idle state. once in the idle state, two auto refresh cycles must be performed. after the auto refresh cycles are complete, the sdram is ready for mode register pro- gramming. because the mode register will power up in an unknown state, it should be loaded prior to applying any operational command. 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 figure 1. 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 inter- leaved), 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. burst length read and write accesses to the sdram are burst oriented, with the burst length being programmable, as shown in figure 1. the burst length determines the maximum number of column locations 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 operation 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-a9 (x4), a1-a8 (x8) or a1-a7 (x16) when the burst length is set to two; by a2-a9 (x4), a2-a8 (x8) or a2-a7 (x16) when the burst length is set to four; and by a3-a9 (x4), a3-a8 (x8) or 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.
9 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. note: 1. for full-page accesses: y = 1,024 (x4); y = 512 (x8); y = 256 (x16). 2. for a burst length of two, a1-a9 (x4), a1-a8 (x8), or a1-a7 (x16) select the block-of-two burst; a0 selects the starting column within the block. 3. for a burst length of four, a2-a9 (x4), a2-a8 (x8), or a2-a7 (x16) select the block-of-four burst; a0- a1 select the starting column within the block. 4. for a burst length of eight, a3-a9 (x4), a3-a8 (x8), or a3-a7 (x16) select the block-of-eight burst; a0-a2 select the starting column within the block. 5. for a full-page burst, the full row is selected and a0-a9 (x4), a0-a8 (x8), or a0-a7 (x16) select the starting column. 6. whenever a boundary of the block is reached within a given sequence above, the following access wraps within the block. 7. for a burst length of one, a0-a9 (x4), a0-a8 (x8), or a0-a7 (x16) select the unique column to be accessed, and mode register bit m3 is ignored. table 1 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-a9/8/7 cn, cn + 1, cn + 2 page cn + 3, cn + 4... not supported (y) (location 0-y) cn - 1, cn m3 = 0 1 2 4 8 reserved reserved reserved full page m3 = 1 1 2 4 8 reserved reserved reserved reserved operating mode standard operation all other states reserved 0 - 0 - defined - 0 1 burst type sequential interleaved cas latency reserved reserved 2 3 reserved reserved reserved reserved burst length m0 0 1 0 1 0 1 0 1 burst length cas latency bt a9 a7 a6 a5 a4 a3 a8 a2 a1 a0 mode register (mx) address bus 9 7 654 3 8 2 1 0 m1 0 0 1 1 0 0 1 1 m2 0 0 0 0 1 1 1 1 m3 m4 0 1 0 1 0 1 0 1 m5 0 0 1 1 0 0 1 1 m6 0 0 0 0 1 1 1 1 m6-m0 m8 m7 op mode a10 a11 10 11 reserved* wb 0 1 write burst mode programmed burst length single location access m9 *should program m11, m10 = 0, 0 to ensure compatibility with future devices. figure 1 mode register definition 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 deter- mined by the burst length, the burst type and the starting column address, as shown in table 1.
10 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. allowable operating frequency (mhz) cas cas speed latency = 2 latency = 3 -7g C 143 -7e 133 143 -75 100 133 -8e 100 125 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 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. cas latency the cas latency is the delay, in clock cycles, be- tween 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 figure 2. table 2 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. figure 2 cas latency clk dq t2 t1 t3 t0 cas latency = 3 lz d out t oh t command nop read t ac nop t4 nop dont care undefined clk dq t2 t1 t3 t0 cas latency = 2 lz d out t oh t command nop read t ac nop table 2 cas latency
11 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. truth table 1 C commands and dqm operation (notes: 1) name (function) cs# ras# cas# we# dqm addr dqs notes command inhibit (nop) h xxxx x x no operation (nop) l h h h x x x active (select bank and activate row) l l h h x bank/row x 3 read (select bank and column, and start read burst) l h l h l/h 8 bank/col x 4 write (select bank and column, and start write burst) l h l l l/h 8 bank/col valid 4 burst terminate l h h l x x active precharge (deactivate row in bank or banks) l l h l x code x 5 auto refresh or self refresh l l l h x x x 6, 7 (enter self refresh mode) load mode register l l l l x op-code x 2 write enable/output enable CCCCl C active 8 write inhibit/output high-z CCCCh C high-z 8 tables appear following the operation section; these tables provide current state/next state information. commands truth table 1 provides a quick reference of available commands. this is followed by a written description of each command. three additional truth note: 1. cke is high for all commands shown 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-a9 (x4), a0-a8 (x8), or a0-a7 (x16) provide column address; a10 high enables the auto precharge feature (nonpersistent), while a10 low disables the auto precharge feature; 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 dont care. 6. this command is 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 dont care except for cke. 8. activates or deactivates the dqs during writes (zero-clock delay) and reads (two-clock delay).
12 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. command inhibit the command inhibit function prevents new commands from being executed by the sdram, regard- less of whether the clk signal is enabled. the sdram is effectively deselected. operations already in progress are not affected. no operation (nop) the no operation (nop) command is used to perform a nop to an sdram which is selected (cs# is low). this prevents unwanted commands from being registered during idle or wait states. operations already in progress are not affected. load mode register the mode register is loaded via inputs a0-a11. see mode register heading in the register definition section. the load mode register command can only be issued when all banks are idle, and a subsequent executable command cannot be issued until t mrd is met. active the active command is used to open (or activate) a row in a particular bank for a subsequent access. the value on the ba0, ba1 inputs selects the bank, and the address provided on inputs a0-a11 selects the row. this row remains active (or open) for accesses until a precharge command is issued to that bank. a precharge command must be issued before open- ing a different row in the same bank. read the read command is used to initiate a burst read access to an active row. the value on the ba0, ba1 inputs selects the bank, and the address provided on inputs a0-a9 (x4), a0-a8 (x8), or a0-a7 (x16) selects the starting column location. the value on input a10 determines whether or not auto precharge is used. if auto precharge is selected, the row being accessed will be precharged at the end of the read burst; if auto precharge is not selected, the row will remain open for subsequent accesses. read data appears on the dqs subject to the logic level on the dqm inputs two clocks earlier. if a given dqm signal was registered high, the corresponding dqs will be high-z two clocks later; if the dqm signal was registered low, the dqs will provide valid data. write the write command is used to initiate a burst write access to an active row. the value on the ba0, ba1 inputs selects the bank, and the address provided on inputs a0-a9 (x4), a0-a8 (x8), or a0-a7 (x16) selects the starting column location. the value on input a10 determines whether or not auto precharge is used. if auto precharge is selected, the row being accessed will be precharged at the end of the write burst; if auto precharge is not selected, the row will remain open for subsequent accesses. input data appearing on the dqs is written to the memory array subject to the dqm input logic level appearing coincident with the data. if a given dqm signal is registered low, the correspond- ing data will be written to memory; if the dqm signal is registered 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. the bank(s) will be available for a subsequent row access a specified time ( t rp) after the precharge command is issued. input a10 determines 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. otherwise ba0, ba1 are treated as dont care. 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 auto precharge is a feature which performs the same individual-bank precharge function described above, without requiring an explicit command. this is accom- plished by using a10 to enable auto precharge in conjunction with a specific read or write command. a precharge of the bank/row that is addressed with the read or write command is automatically performed upon completion of the read or write burst, except in the full-page burst mode, where auto precharge does not apply. auto precharge is nonpersistent in that it is either enabled or disabled for each individual read or write command. auto precharge ensures that the precharge is initi- ated at the earliest valid stage within a burst. the user must not issue another command to the same bank until the precharge time ( t rp) is completed. this is determined as if an explicit precharge command was issued at the earliest possible time, as described for each burst type in the operation section of this data sheet. burst terminate the burst terminate command is used to trun- cate either fixed-length or full-page bursts. the most recently registered read or write command prior to the burst terminate command will be truncated, as shown in the operation section of this data sheet.
13 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. auto refresh auto refresh is used during normal operation of the sdram and is analagous to cas#-before-ras# (cbr) refresh in conventional drams. this com- mand is nonpersistent, so it must be issued each time a refresh is required. the addressing is generated by the internal refresh controller. this makes the address bits dont care during an auto refresh command. the 64mb sdram requires 4,096 auto refresh cycles every 64ms ( t ref), regardless of width option. providing a distributed auto refresh command every 15.625s will meet the refresh requirement and ensure that each row is refreshed. alternatively, 4,096 auto refresh com- mands can be issued in a burst at the minimum cycle rate ( t rc), once every 64ms. self refresh the self refresh command can be used to retain data in the sdram, even if the rest of the system is powered down. when in the self refresh mode, the sdram retains data without external clocking. the self refresh command is initiated like an auto refresh command except cke is disabled (low). once the self refresh command is registered, all the inputs to the sdram become dont care, with the exception of cke, which must remain low. once self refresh mode is engaged, the sdram provides its own internal clocking, causing it to per- form its own auto refresh cycles. the sdram must remain in self refresh mode for a minimum period equal to t ras and may remain in self refresh mode for an indefinite period beyond that. the procedure for exiting self refresh requires a sequence of commands. first, clk must be stable (stable clock is defined as a signal cycling within timing constraints specified for the clock pin) prior to cke going back high. once cke is high, the sdram must have nop commands issued (a minimum of two clocks) for t xsr, because time is required for the completion of any internal refresh in progress. upon exiting the self refresh mode, auto refresh commands must be issued every 15.625s or less as both self refresh and auto refresh utilize the row refresh counter.
14 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. 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 figure 3). 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. t rcd (min) 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 specifi- cation of 20ns with a 125 mhz clock (8ns period) results in 2.5 clocks, rounded to 3. this is reflected in figure 4, which covers any case where 2 < t rcd (min)/ t ck 3. (the same procedure is used to convert other specifica- tion 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 mini- mum time interval between successive active com- mands 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 over- head. the minimum time interval between successive active commands to different banks is defined by t rrd. figure 4 example: meeting t rcd (min) when 2 < t rcd (min)/ t ck < 3 clk t2 t1 t3 t0 t command nop active read or write t4 nop rcd dont care cs# we# cas# ras# cke clk a0-a11 row address high ba0, ba1 bank address figure 3 activating a specific row in a specific bank
15 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. 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 continu- ous 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. reads read bursts are initiated with a read command, as shown in figure 5. the starting column and bank addresses are pro- vided 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 illustra- tions, 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. figure 6 shows general timing for each possible cas latency setting. figure 5 read command figure 6 cas latency clk dq t2 t1 t3 t0 cas latency = 3 lz d out t oh t command nop read t ac nop t4 nop dont care undefined clk dq t2 t1 t3 t0 cas latency = 2 lz d out t oh t command nop read t ac nop cs# we# cas# ras# cke clk column address a0-a9: x4 a0-a8: x8 a0-a7: x16 a10 ba0,1 high enable auto precharge disable auto precharge bank address a11: x4 a9, a11: x8 a8, a9, a11: x16
16 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. 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 figure 7 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 figure 7 consecutive read bursts does not require the 2 n 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 figure 8, or each subsequent read may be performed to a different bank. note: each read command may be to any bank. dqm is low. clk dq d out n t2 t1 t4 t3 t6 t5 t0 command address read nop nop nop nop bank, col n nop bank, col b d out n + 1 d out n + 2 d out n + 3 d out b read x = 1 cycle cas latency = 2 clk dq d out n t2 t1 t4 t3 t6 t5 t0 command address read nop nop nop nop bank, col n nop bank, col b d out n + 1 d out n + 2 d out n + 3 d out b read nop t7 x = 2 cycles cas latency = 3 dont care
17 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. figure 8 random read accesses clk dq t2 t1 t4 t3 t6 t5 t0 command address read nop nop bank, col n d out n d out a d out x d out m read note: each read command may be to any bank. dqm is low. read read nop bank, col a bank, col x bank, col m clk dq d out n t2 t1 t4 t3 t5 t0 command address read nop bank, col n d out a d out x d out m read read read nop bank, col a bank, col x bank, col m cas latency = 2 cas latency = 3 dont care
18 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. 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 turn- around limitations). the write burst may be initiated on the clock edge immediately following the last (or last desired) data element from the read burst, pro- vided 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 9 and 10. the dqm signal must be asserted (high) at least two clocks prior to the write command (dqm latency is two clocks for output dont care read nop nop nop nop dqm clk dq d out n t2 t1 t4 t3 t0 command address bank, col n write d in b bank, col b t5 ds t hz t note: a cas latency of three is used for illustration. the read command may be to any bank, and the write command may be to any bank. figure 10 read to write with extra clock cycle dont care read nop nop write nop clk t2 t1 t4 t3 t0 dqm dq d out n command d in b address bank, col n bank, col b ds t hz t t ck note: a cas latency of three is used for illustration. the read command may be to any bank, and the write command may be to any bank. if a burst of one is used, then dqm is not required. 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 10, 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 9 shows the case where the clock frequency allows for bus contention to be avoided without adding a nop cycle, and figure 10 shows the case where the additional nop is needed. figure 9 read to write
19 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. figure 11 read to precharge 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 command to the 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 figure 11 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 dont care clk dq d out n t2 t1 t4 t3 t6 t5 t0 command address read nop nop nop nop nop d out n + 1 d out n + 2 d out n + 3 precharge active t rp t7 note: dqm is low. clk dq d out n t2 t1 t4 t3 t6 t5 t0 command address read nop nop nop nop nop d out n + 1 d out n + 2 d out n + 3 precharge active t rp t7 x = 1 cycle cas latency = 2 cas latency = 3 x = 2 cycles bank a , col n bank a , row bank ( a or all) bank a , col n bank a , row bank ( a or all)
20 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. figure 12 terminating a read burst precharge command is that it requires that the command and address buses be available at the appro- priate time to issue the command; the advantage of the precharge command is that it can be used to trun- cate 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 acti- vated. 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 figure 12 for each possible cas latency; data element n + 3 is the last desired data element of a longer burst. dont care clk dq d out n t2 t1 t4 t3 t6 t5 t0 command address read nop nop nop nop bank, col n nop d out n + 1 d out n + 2 d out n + 3 burst terminate nop t7 note: dqm is low. clk dq d out n t2 t1 t4 t3 t6 t5 t0 command address read nop nop nop bank, col n nop d out n + 1 d out n + 2 d out n + 3 burst terminate nop x = 1 cycle cas latency = 2 cas latency = 3 x = 2 cycles
21 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. writes write bursts are initiated with a write command, as shown in figure 13. 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 illus- trations, auto precharge is disabled. during write bursts, the first valid data-in element will be registered coincident with the write com- mand. 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 figure 14). 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. figure 15 write to write an example is shown in figure 15. 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 architecture and therefore does not require the 2 n 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 figure 16, or each subsequent write may be performed to a different bank. clk dq d in n t2 t1 t3 t0 command address nop nop write d in n + 1 nop bank, col n note: burst length = 2. dqm is low. figure 14 write burst dont care clk dq t2 t1 t0 command address nop write write bank, col n bank, col b d in n d in n + 1 d in b note: dqm is low. each write command may be to any bank. cs# we# cas# ras# cke clk column address a10 high enable auto precharge disable auto precharge a0-a9: x4 a0-a8: x8 a0-a7: x16 a11: x4 a9, a11: x8 a8, a9, a11: x16 ba0,1 bank address figure 13 write command
22 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. the clock edge at which the last desired input data element is registered. the auto precharge mode re- quires 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 coinci- dent with, the precharge command. an example is shown in figure 18. 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 command to the same bank cannot be issued until t rp is met. 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 command and address buses be available at the appro- priate time to issue the command; the advantage of the precharge command is that it can be used to trun- cate fixed-length or full-page bursts. figure 18 write to precharge dont care dqm clk dq t2 t1 t4 t3 t0 command address bank a , col n t5 nop write precharge nop nop d in n d in n + 1 active t rp bank ( a or all) t wr bank a , row dqm dq command address bank a , col n nop write precharge nop nop d in n d in n + 1 active t rp bank ( a or all) t wr note: dqm could remain low in this example if the write burst is a fixed length of two. bank a , row t6 nop nop t wr@ t ck 15ns t wr@ t ck < 15ns data for any write burst may be truncated with a subsequent read command, and data for a fixed- length write burst may be immediately followed by a subsequent read command. once the read com- mand is registered, the data inputs will be ignored, and writes will not be executed. an example is shown in figure 17. 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 fol- lowed 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 trun- cated with a precharge command to the same bank. the precharge command should be issued t wr after figure 17 write to read clk dq t2 t1 t3 t0 command address nop write bank, col n d in n d in n + 1 d out b read nop nop bank, col b nop d out b + 1 t4 t5 note: the write command may be to any bank, and the read command may be to any bank. dqm is low. cas latency = 2 for illustration. figure 16 random write cycles clk dq d in n t2 t1 t3 t0 command address write bank, col n d in a d in x d in m write write write bank, col a bank, col x bank, col m note: each write command may be to any bank. dqm is low.
23 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. fixed-length or full-page write bursts can be trun- cated with the burst terminate command. when truncating a write burst, the input data applied coin- cident 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 figure 19, where data n is the last desired data element of a longer burst. figure 21 power-down dont care t ras t rcd t rc all banks idle input buffers gated off exit power-down mode. ( ) ( ) ( ) ( ) ( ) ( ) t cks > t cks command nop active enter power-down mode. nop clk cke ( ) ( ) ( ) ( ) figure 20 precharge command figure 19 terminating a write burst cs# we# cas# ras# cke clk a10 high all banks bank selected a0-a9, a11 ba0,1 bank address clk dq t2 t1 t0 command address bank, col n write burst terminate next command d in n (address) (data) note: dqms are low. precharge the precharge command (figure 20) 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 dont care. 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. power-down power-down occurs if cke is registered low coinci- dent 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 in- put 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 per- formed 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 21.
24 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. dq command address write bank, col n d in n nop nop clk t2 t1 t4 t3 t5 t0 cke internal clock nop d in n + 1 d in n + 2 note: for this example, burst length = 4 or greater, and dqm is low. figure 22 clock suspend during write burst dont care clk dq d out n t2 t1 t4 t3 t6 t5 t0 command address read nop nop nop bank, col n nop d out n + 1 d out n + 2 d out n + 3 note: for this example, cas latency = 2, burst length = 4 or greater, and dqm is low. cke internal clock nop figure 23 clock suspend during read burst clock suspend the 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 deac- tivated, freezing the synchronous logic. for each positive clock edge on which cke is sampled low, the next internal positive clock edge is sus- pended. 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 examples in figures 22 and 23.) clock suspend mode is exited by registering cke high; the internal clock and related operation will resume on the subsequent positive clock edge. 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 accord- ing to the programmed burst length and sequence, just as in the normal mode of operation (m9 = 0).
25 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. 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. micron 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 (figure 24). 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 (figure 25). clk dq d out a t2 t1 t4 t3 t6 t5 t0 command read - ap bank n nop nop nop nop d out a + 1 d out d d out d + 1 nop t7 bank n cas latency = 3 (bank m ) bank m address idle nop note: d q m is low. bank n , col a bank m , col d read - ap bank m internal states t page active read with burst of 4 interrupt burst, precharge page active read with burst of 4 precharge rp - bank n t rp - bank m cas latency = 3 (bank n ) figure 24 read with auto precharge interrupted by a read clk dq d out a t2 t1 t4 t3 t6 t5 t0 command nop nop nop nop d in d + 1 d in d d in d + 2 d in d + 3 nop t7 bank n bank m address idle nop dqm note: 1. dqm is high at t2 to prevent d out - a +1 from contending with d in - d at t4. bank n , col a bank m , col d write - ap bank m internal states t page active read with burst of 4 interrupt burst, precharge page active write with burst of 4 write-back rp - bank n t wr - bank m cas latency = 3 (bank n ) read - ap bank n 1 dont care figure 25 read with auto precharge interrupted by a write
26 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. clk dq t2 t1 t4 t3 t6 t5 t0 command write - ap bank n nop nop nop nop d in a + 1 d in a nop nop t7 bank n bank m address note: 1. dqm is low. bank n , col a bank m , col d read - ap bank m internal states t page active write with burst of 4 interrupt burst, write-back precharge page active read with burst of 4 t t rp - bank m d out d d out d + 1 cas latency = 3 (bank m ) rp - bank n wr - bank n figure 26 write with auto precharge interrupted by a read dont care clk dq t2 t1 t4 t3 t6 t5 t0 command write - ap bank n nop nop nop nop d in d + 1 d in d d in a + 1 d in a + 2 d in a d in d + 2 d in d + 3 nop t7 bank n bank m address nop note: 1. dqm is low. bank n , col a bank m , col d write - ap bank m internal states t page active write with burst of 4 interrupt burst, write-back precharge page active write with burst of 4 write-back wr - bank n t rp - bank n t wr - bank m figure 27 write with auto precharge interrupted by a write 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 appear- ing 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 (figure 26). 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 (figure 27).
27 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. truth table 2 C cke (notes: 1-4) cke n-1 cke n current state command n action n notes l l power-down x maintain power-down self refresh x maintain self refresh clock suspend x maintain clock suspend l h power-down command inhibit or nop exit power-down 5 self refresh command inhibit or nop exit self refresh 6 clock suspend x exit clock suspend 7 h l all banks idle command inhibit or nop power-down entry all banks idle auto refresh self refresh entry reading or writing valid clock suspend entry h h see truth table 3 note: 1. cke n is the logic state of cke at clock edge n ; cke n-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. command n is the command registered at clock edge n , and action n is a result of command n . 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 the all banks idle state once t xsr is met. command inhibit or nop commands should be issued on any clock edges occurring during the t xsr period. a minimum of two nop commands must be provided 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 .
28 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. truth table 3 C current state bank n , command to bank n (notes: 1-6; notes appear below and on next page) current state cs# ras#cas# we# command (action) notes any h x x x command inhibit (nop/continue previous operation) l h h h no operation (nop/continue previous operation) l l h h active (select and activate row) idle l l l h auto refresh 7 llll load mode register 7 l l h l precharge 11 l h l h read (select column and start read burst) 10 row active l h l l write (select column and start write burst) 10 l l h l precharge (deactivate row in bank or banks) 8 read l h l h read (select column and start new read burst) 10 (auto l h l l write (select column and start write burst) 10 precharge l l h l precharge (truncate read burst, start precharge) 8 disabled) l h h l burst terminate 9 write l h l h read (select column and start read burst) 10 (auto l h l l write (select column and start new write burst) 10 precharge l l h l precharge (truncate write burst, start precharge) 8 disabled) l h h l burst terminate 9 note: 1. this table applies when cke n-1 was high and cke n is high (see truth table 2) 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 those 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 truth table 3, and according to truth table 4. 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. (continued on next page)
29 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. note (continued): 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.
30 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. truth table 4 C current state bank n, command to bank m (notes: 1-6; notes appear below and on next page) current state cs# ras# cas# we# command (action) notes any h x x x command inhibit (nop/continue previous operation) l h h h no operation (nop/continue previous operation) idle xxxx any command otherwise allowed to bank m row l l h h active (select and activate row) activating, l h l h read (select column and start read burst) 7 active, or l h l l write (select column and start write burst) 7 precharging l l h l precharge read l l h h active (select and activate row) (auto l h l h read (select column and start new read burst) 7, 10 precharge l h l l write (select column and start write burst) 7, 11 disabled) l l h l precharge 9 write l l h h active (select and activate row) (auto l h l h read (select column and start read burst) 7, 12 precharge l h l l write (select column and start new write burst) 7, 13 disabled) l l h l precharge 9 read l l h h active (select and activate row) (with auto l h l h read (select column and start new read burst) 7, 8, 14 precharge) l h l l write (select column and start write burst) 7, 8, 15 l l h l precharge 9 write l l h h active (select and activate row) (with auto l h l h read (select column and start read burst) 7, 8, 16 precharge) l h l l write (select column and start new write burst) 7, 8, 17 l l h l precharge 9 note: 1. this table applies when cke n-1 was high and cke n is high (see truth table 2) 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. (continued on next page)
31 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. note (continued): 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. 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 interrupted 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 (figure 7). 11. for a read without auto precharge interrupted by a write (with or without auto precharge), the write to bank m will interrupt the read on bank n when registered (figures 9 and 10). 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 (figure 17), 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 interrupt the write on bank n when registered (figure 15). 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 (figure 24). 15. for a read with auto precharge interrupted by a write (with or without auto precharge), the write to bank m will interrupt the 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 (figure 25). 16. for a write with 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, 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 (figure 26). 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 (figure 27).
32 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. absolute maximum ratings* voltage on v dd , v dd q supply relative to v ss ....................................... -1v to +4.6v voltage on inputs, nc or i/o pins relative to v ss ....................................... -1v to +4.6v operating temperature, t a (commercial) ................................. 0c to +70c operating temperature, t a (industrial) .................................. -40c to +85c storage temperature (plastic) ............ -55c to +150c power dissipation ................................................... 1w *stresses 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 operational sections of this specification is not implied. exposure to absolute maximum rating conditions for extended periods may affect reliability. dc electrical characteristics and operating conditions (notes: 1, 6; notes appear on page 35) (0c t a +70c; v dd , v dd q = +3.3v 0.3v) parameter/condition symbol min max units notes supply voltage v dd , v dd q 3 3.6 v input high voltage: logic 1; all inputs v ih 2v dd + 0.3 v 22 input low voltage: logic 0; all inputs v il -0.3 0.8 v 22 input leakage current: any input 0v v in v dd i i -5 5 a (all other pins not under test = 0v) output leakage current: dqs are disabled; 0v v out v dd qi oz -5 5 a output levels: v oh 2.4Cv output high voltage (i out = -4ma) output low voltage (i out = 4ma) v ol C 0.4 v i dd specifications and conditions (notes: 1, 6, 11, 13, 33; notes appear on page 35) (0c t a +70c; v dd , v dd q = +3.3v 0.3v) parameter/condition symbol -7e -7g -75 -8e units notes operating current: active mode; i dd 1 125 125 115 95 ma 3, 18, burst = 2; read or write; t rc = t rc (min); cas latency = 3 19, 32 standby current: power-down mode; all banks idle; i dd 2 2 222 ma 32 cke = low standby current: active mode; i dd 3 45 45 45 35 ma 3, 12, cke = high; cs# = high; all banks active after t rcd met; 19, 32 no accesses in progress operating current: burst mode; continuous burst; i dd 4 150 150 140 120 ma 3, 18, read or write; all banks active; cas latency = 3 19, 32 auto refresh current: t rfc = t rfc (min); cl = 3 i dd 5 230 230 210 190 ma 3, 12, cke = high; cs# = high 18, 19, t rfc = 15.625s; cl = 3 i dd 6 3 3 3 3 ma 32, 34 self refresh current: standard i dd 7 1 111 ma 4 cke 0.2v low power (l) i dd 7 0.5 0.5 0.5 0.5 ma max
33 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. capacitance parameter symbol min max units notes input capacitance: clk c i 1 2.5 3.5 pf 29 input capacitance: all other input-only pins c i 2 2.5 3.8 pf 30 input/output capacitance: dqs c io 4.0 6.0 pf 31 electrical characteristics and recommended ac operating conditions (notes: 5, 6, 8, 9, 11, 33; notes appear on page 35) (0c t a +70c) ac characteristics -7e -75 -7g -8e parameter symbol min max min max min max min max units notes access time from clk (pos. edge) cl = 3 t ac 5.4 5.4 6 6 ns 27 cl = 2 t ac 5.4 6 C 6 ns address hold time t ah 0.8 0.8 1 1 ns address setup time t as 1.5 1.5 2 2 ns clk high-level width t ch 2.5 2.5 2.75 3 ns clk low-level width t cl 2.5 2.5 2.75 3 ns clock cycle time cl = 3 t ck 7 7.5 7 8 ns 23 cl = 2 t ck 7.5 10 C 10 ns 23 cke hold time t ckh 0.8 0.8 1 1 ns cke setup time t cks 1.5 1.5 2 2 ns cs#, ras#, cas#, we#, dqm hold time t cmh 0.8 0.8 1 1 ns cs#, ras#, cas#, we#, dqm setup time t cms 1.5 1.5 2 2 ns data-in hold time t dh 0.8 0.8 1 1 ns data-in setup time t ds 1.5 1.5 2 2 ns data-out high-impedance time cl = 3 t hz 5.4 5.4 6 6 ns 10 cl = 2 t hz 5.4 6 C 7 ns 10 data-out low-impedance time t lz1111ns data-out hold time (load) t oh 2.7 2.7 2.5 3 ns data-out hold time (no load) t oh n 1.8 1.8 1.8 1.8 ns 28 active to precharge command t ras 37 120,000 44 120,000 42 120,000 50 120,000 ns active to active command period t rc 60 66 70 70 ns active to read or write delay t rcd 15 20 21 20 ns refresh period (4,096 rows) t ref 64 64 64 64 ms auto refresh period t rfc 66 66 70 70 ns precharge command period t rp 15 20 21 20 ns active bank a to active bank b command t rrd 14 15 14 20 ns transition time t t 0.3 1.2 0.3 1.2 0.3 1.2 0.3 1.2 ns 7 write recovery time t wr 1 clk + 1 clk + 1 clk + 1 clk + C 24 7ns 7.5ns 7ns 7ns 14 15 14 15 ns 25 exit self refresh to active command t xsr 67 75 77 80 ns
34 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. ac functional characteristics (notes: 5, 6, 7, 8, 9, 11; notes appear on page 35) (0c t a +70c) parameter symbol -7g -7e -7 -75 -8e units notes read/write command to read/write command t ccd11111 t ck 17 cke to clock disable or power-down entry mode t cked 11111 t ck 14 cke to clock enable or power-down exit setup mode t ped11111 t ck 14 dqm to input data delay t dqd00000 t ck 17 dqm to data mask during writes t dqm00000 t ck 17 dqm to data high-impedance during reads t dqz22222 t ck 17 write command to input data delay t dwd00000 t ck 17 data-in to active command t dal54454 t ck 15, 21 data-in to precharge command t dpl22222 t ck 16, 21 last data-in to burst stop command t bdl11111 t ck 17 last data-in to new read/write command t cdl11111 t ck 17 last data-in to precharge command t rdl22222 t ck 16, 21 load mode register command to active or refresh command t mrd22222 t ck 26 data-out to high-impedance from precharge command cl = 3 t roh33333 t ck 17 cl = 2 t roh22222 t ck 17
35 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. 14. timing actually specified by t cks; clock(s) speci- fied as a reference only at minimum cycle rate. 15. timing actually specified by t wr plus t rp; clock(s) specified as a reference only at minimum cycle rate. 16. timing actually specified by t wr. 17. required clocks are specified by jedec functional- ity and are not dependent on any timing param- eter. 18. the i dd current will decrease as the cas latency is reduced. this is due to the fact that the maximum cycle rate is slower as the cas latency is reduced. 19. address transitions average one transition every two clocks. 20. clk must be toggled a minimum of two times during this period. 21. based on t ck = 143 mhz for -7e/-7g, 133 mhz for -75 and 100 mhz for -8e. 22. v ih overshoot: v ih (max) = v dd q + 2v for a pulse width 3ns, and the pulse width cannot be greater than one third of the cycle rate. v il undershoot: v il (min) = -2v for a pulse width 3ns. 23. the clock frequency must remain constant (stable clock is defined as a signal cycling within timing constraints specified for the clock pin) during ac- cess or precharge states (read, write, including t wr, and precharge commands). cke may be used to reduce the data rate. 24. auto precharge mode only. the precharge timing budget ( t rp) begins 7.5ns/7ns after the first clock delay, after the last write is executed. 25. precharge mode only. 26. jedec and pc100 specify three clocks. 27. t ac for -7e/-75 at cl = 3 with no load is 4.6ns and is guaranteed by design. 28. parameter guaranteed by design. 29. pc100 specifies a maximum of 4pf. 30. pc100 specifies a maximum of 5pf. 31. pc100 specifies a maximum of 6.5pf. 32. t ck = 7ns for -7e/-7g, 7.5ns for -75 and 10ns for -8e. 33. for -7g, v dd (min) = 3.15v, t a (max) = 55c. 34. cke is high during refresh command period ( t rfc [min]) else cke is low. the i dd 6 limit is actually a nominal value and does not result in a fail value. notes 1. all voltages referenced to v ss . 2. this parameter is sampled. v dd , v dd q = +3.3v; f = 1 mhz, t a = 25c; pin under test biased at 1.4v. 3. i dd is dependent on output loading and cycle rates. specified values are obtained with minimum cycle time and the outputs open. 4. enables on-chip refresh and address counters. 5. the minimum specifications are used only to indicate cycle time at which proper operation over the full temperature range (0c t a +70c) is ensured. 6. an initial pause of 100s is required after power-up, followed by two auto refresh commands, be- fore proper device operation is ensured. (v dd and v dd q must be powered up simultaneously. v ss and v ss q must be at same potential.) the two auto refresh command wake-ups should be repeated any time the t ref refresh requirement is exceeded. 7. ac characteristics assume t t = 1ns. 8. in addition to meeting the transition rate specifica- tion, the clock and cke must transit between v ih and v il (or between v il and v ih ) in a monotonic manner. 9. outputs measured at 1.5v with equivalent load: 10. t hz defines the time at which the output achieves the open circuit condition; it is not a reference to v oh or v ol . the last valid data element will meet t oh before going high-z. 11. ac timing and i dd tests have v il = 0v and v ih = 3v, with timing referenced to 1.5v crossover point. if the input transition time is longer than 1ns, then the timing is referenced at v il (max) and v il (min) and no longer at the 1.5v crossover point. 12. other input signals are allowed to transition no more than once every two clocks and are otherwise at valid v ih or v il levels. 13. i dd specifications are tested after the device is properly initialized. q 50pf (-7g @ 30pf)
36 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. initialize and load mode register 1 t ch t cl t ck cke clk command dq ba0, ba1 bank t rfc t mrd t rfc auto refresh auto refresh program mode register 2, 3, 4 t cms t cmh precharge all banks ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) t rp ( ) ( ) ( ) ( ) t cks power-up: v dd and clk stable t = 100s min precharge nop auto refresh nop load mode register active nop nop nop ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) auto refresh all banks ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) high-z t ckh ( ) ( ) ( ) ( ) dqm / dqml, dqmh ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) nop ( ) ( ) ( ) ( ) t cms t cmh t cms t cmh a0-a9, a11 row t ah t as code ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) a10 row t ah t as code ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) all banks single bank ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) dont care t0 t1 tn + 1 to + 1 tp + 1 tp + 2 tp + 3 timing parameters -7e -75 -8e symbol* min max min max min max units t ah 0.8 0.8 1 ns t as 1.5 1.5 2 ns t ch 2.5 2.5 3 ns t cl 2.5 2.5 3 ns t ck (3) 7 7.5 8 ns t ck (2) 7.5 10 10 ns t ckh 0.8 0.8 1 ns -7e -75 -8e symbol* min max min max min max units t cks 1.5 1.5 2 ns t cmh 0.8 0.8 1 ns t cms 1.5 1.5 2 ns t mrd 3 2 22 t ck t rfc 66 66 70 ns t rp 15 20 20 ns *cas latency indicated in parentheses. note: 1. if cs# is high at clock high time, all commands applied are nop, with cke a dont care. 2. the mode register may be loaded prior to the auto refresh cycles if desired. 3. jedec and pc100 specify three clocks. 4. outputs are guaranteed high-z after command is issued.
37 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. note: 1. violating refresh requirements during power-down may result in a loss of data. power-down mode 1 t ch t cl t ck two clock cycles cke clk dq all banks idle, enter power-down mode precharge all active banks input buffers gated off while in power-down mode exit power-down mode ( ) ( ) ( ) ( ) dont care t cks t cks command t cmh t cms precharge nop nop active nop ( ) ( ) ( ) ( ) all banks idle ba0, ba1 bank bank(s) ( ) ( ) ( ) ( ) high-z t ah t as t ckh t cks dqm / dqml, dqmh ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) a0-a9, a11 row ( ) ( ) ( ) ( ) all banks single bank a10 row ( ) ( ) ( ) ( ) t0 t1 t2 tn + 1 tn + 2 t ck (2) 7.5 10 10 ns t ckh 0.8 0.8 1 ns t cks 1.5 1.5 2 ns t cmh 0.8 0.8 1 ns t cms 1.5 1.5 2 ns timing parameters -7e -75 -8e symbol* min max min max min max units t ah 0.8 0.8 1 ns t as 1.5 1.5 2 ns t ch 2.5 2.5 3 ns t cl 2.5 2.5 3 ns t ck (3) 7 7.5 8 ns *cas latency indicated in parentheses. -7e -75 -8e symbol* min max min max min max units
38 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. clock suspend mode 1 timing parameters -7e -75 -8e symbol* min max min max min max units t ac (3) 5.4 5.4 6 ns t ac (2) 5.4 6 6 ns t ah 0.8 0.8 1 ns t as 1.5 1.5 2 ns t ch 2.5 2.5 3 ns t cl 2.5 2.5 3 ns t ck (3) 7 7.5 8 ns t ck (2) 7.5 10 10 ns t ckh 0.8 0.8 1 ns -7e -75 -8e symbol* min max min max min max units t cks 1.5 1.5 2 ns t cmh 0.8 0.8 1 ns t cms 1.5 1.5 2 ns t dh 0.8 0.8 1 ns t ds 1.5 1.5 2 ns t hz (3) 5.4 5.4 6 ns t hz (2) 5.4 6 7 ns t lz111ns t oh 2.7 2.7 3 ns *cas latency indicated in parentheses. t ch t cl t ck t ac t lz dqm / dqml, dqmh clk a0-a9, a11 dq ba0, ba1 a10 t oh d out m t ah t as t ah t as t ah t as bank t dh d out e t ac t hz d out m + 1 command t cmh t cms nop nop nop nop nop read write dont care undefined cke t cks t ckh bank column m t ds d out e + 1 nop t ckh t cks t cmh t cms 2 column e 2 t0 t1 t2 t3 t4 t5 t6 t7 t8 t9 note: 1. for this example, the burst length = 2, the cas latency = 3, and auto precharge is disabled. 2. x16: a8, a9 and a11 = dont care x8: a9 and a11 = dont care x4: a11 = dont care
39 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. auto refresh mode t ch t cl t ck cke clk dq t rfc 1 ( ) ( ) ( ) ( ) ( ) ( ) t rp ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) command t cmh t cms nop nop ( ) ( ) ( ) ( ) bank active auto refresh ( ) ( ) ( ) ( ) nop nop precharge precharge all active banks auto refresh t rfc 1 high-z ba0, ba1 bank(s) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) t ah t as t ckh t cks ( ) ( ) nop ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) dqm / dqml, dqmh a0-a9, a11 row ( ) ( ) ( ) ( ) all banks single bank a10 row ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) t0 t1 t2 tn + 1 to + 1 dont care timing parameters -7e -75 -8e symbol* min max min max min max units t ah 0.8 0.8 1 ns t as 1.5 1.5 2 ns t ch 2.5 2.5 3 ns t cl 2.5 2.5 3 ns t ck (3) 7 7.5 8 ns t ck (2) 7.5 10 10 ns *cas latency indicated in parentheses. t ckh 0.8 0.8 1 ns t cks 1.5 1.5 2 ns t cmh 0.8 0.8 1 ns t cms 1.5 1.5 2 ns t rfc 66 66 70 ns t rp 15 20 20 ns -7e -75 -8e symbol* min max min max min max units note : 1. each auto refresh command performs a refresh cycle. back-to-back commands are not required.
40 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. self refresh mode t cks 1.5 1.5 2 ns t cmh 0.8 0.8 1 ns t cms 1.5 1.5 2 ns t ras 37 120,000 44 120,000 50 120,000 ns t rp 15 20 20 ns t xsr 67 75 80 ns timing parameters -7e -75 -8e symbol* min max min max min max units t ah 0.8 0.8 1 ns t as 1.5 1.5 2 ns t ch 2.5 2.5 3 ns t cl 2.5 2.5 3 ns t ck (3) 7 7.5 8 ns t ck (2) 7.5 10 10 ns t ckh 0.8 0.8 1 ns *cas latency indicated in parentheses. dont care t ch t cl t ck t rp cke clk dq enter self refresh mode precharge all active banks t xsr clk stable prior to exiting self refresh mode exit self refresh mode (restart refresh time base) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) command t cmh t cms auto refresh precharge nop nop ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ba0, ba1 bank(s) ( ) ( ) ( ) ( ) high-z t cks ah as auto refresh > t ras ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) t ckh t cks dqm / dqml, dqmh ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) t t t cks a0-a11 ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) all banks single bank a10 ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) t0 t1 t2 tn + 1 to + 1 to + 2 -7e -75 -8e symbol* min max min max min max units
41 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. read C without auto precharge 1 all banks t ch t cl t ck t ac t lz t rp t ras t rcd cas latency t rc t oh d out m t cmh t cms t ah t as t ah t as t ah t as row row bank bank(s) bank row row bank t hz t oh d out m +3 t ac t oh t ac t oh t ac d out m +2 d out m +1 t cmh t cms precharge nop nop nop active nop read nop active disable auto precharge single banks dont care undefined column m 2 t ckh t cks t0 t1 t2 t3 t4 t5 t6 t7 t8 dqm / dqml, dqmh cke clk a0-a9, a11 dq ba0, ba1 a10 command timing parameters -7e -75 -8e symbol* min max min max min max units t ac (3) 5.4 5.4 6 ns t ac (2) 5.4 6 6 ns t ah 0.8 0.8 1 ns t as 1.5 1.5 2 ns t ch 2.5 2.5 3 ns t cl 2.5 2.5 3 ns t ck (3) 7 7.5 8 ns t ck (2) 7.5 10 10 ns t ckh 0.8 0.8 1 ns t cks 1.5 1.5 2 ns t cmh 0.8 0.8 1 ns t cms 1.5 1.5 2 ns t hz (3) 5.4 5.4 6 ns t hz (2) 5.4 6 7 ns t lz111ns t oh 2.7 2.7 3 ns t ras 37 120,000 44 120,000 50 120,000 ns t rc 60 66 70 ns t rcd 15 20 20 ns t rp 15 20 20 ns *cas latency indicated in parentheses. -7e -75 -8e symbol* min max min max min max units note: 1. for this example, the burst length = 4, the cas latency = 2, and the read burst is followed by a manual precharge. 2. x16: a8, a9 and a11 = dont care x8: a9 and a11 = dont care x4: a11 = dont care
42 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. read C with auto precharge 1 timing parameters -7e -75 -8e symbol* min max min max min max units t ac (3) 5.4 5.4 6 ns t ac (2) 5.4 6 6 ns t ah 0.8 0.8 1 ns t as 1.5 1.5 2 ns t ch 2.5 2.5 3 ns t cl 2.5 2.5 3 ns t ck (3) 7 7.5 8 ns t ck (2) 7.5 10 10 ns t ckh 0.8 0.8 1 ns t cks 1.5 1.5 2 ns t cmh 0.8 0.8 1 ns t cms 1.5 1.5 2 ns t hz (3) 5.4 5.4 6 ns t hz (2) 5.4 6 7 ns t lz111ns t oh 2.7 2.7 3 ns t ras 37 120,000 44 120,000 50 120,000 ns t rc 60 66 70 ns t rcd 15 20 20 ns t rp 15 20 20 ns enable auto precharge t ch t cl t ck t ac t lz t rp t ras t rcd cas latency t rc dqm / dqml, dqmh cke clk a0-a9, a11 dq ba0, ba1 a10 t oh d out m t cmh t cms t ah t as t ah t as t ah t as row row bank bank row row bank dont care undefined t hz t oh d out m + 3 t ac t oh t ac t oh t ac d out m + 2 d out m + 1 command t cmh t cms nop nop nop active nop read nop active nop t ckh t cks column m 2 t0 t1 t2 t4 t3 t5 t6 t7 t8 *cas latency indicated in parentheses. -7e -75 -8e symbol* min max min max min max units note: 1. for this example, the burst length = 4, and the cas latency = 2. 2. x16: a8, a9 and a11 = dont care x8: a9 and a11 = dont care x4: a11 = dont care
43 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. single read C without auto precharge 1 timing parameters -7e -75 -8e symbol* min max min max min max units t ac (3) 5.4 5.4 6 ns t ac (2) 5.4 6 6 ns t ah 0.8 0.8 1 ns t as 1.5 1.5 2 ns t ch 2.5 2.5 3 ns t cl 2.5 2.5 3 ns t ck (3) 7 7.5 8 ns t ck (2) 7.5 10 10 ns t ckh 0.8 0.8 1 ns t cks 1.5 1.5 2 ns t cmh 0.8 0.8 1 ns t cms 1.5 1.5 2 ns t hz (3) 5.4 5.4 6 ns t hz (2) 5.4 6 7 ns t lz111ns t oh 2.7 2.7 3 ns t ras 37 120,000 44 120,000 50 120,000 ns t rc 60 66 70 ns t rcd 15 20 20 ns t rp 15 20 20 ns *cas latency indicated in parentheses. all banks t ch t cl t ck t ac t lz t rp t ras t rcd cas latency t rc t oh d out m t cmh t cms t ah t as t ah t as t ah t as row row bank bank(s) bank row row bank t hz t cmh t cms nop nop 3 nop precharge active nop read active nop disable auto precharge single banks column m 2 t ckh t cks t0 t1 t2 t3 t4 t5 t6 t7 t8 dqm / dqml, dqmh cke clk a0-a9, a11 dq ba0, ba1 a10 command dont care undefined -7e -75 -8e symbol* min max min max min max units note: 1. for this example, the burst length = 1, the cas latency = 2, and the read burst is followed by a manual precharge. 2. x16: a8, a9 and a11 = dont care x8: a9 and a11 = dont care x4: a11 = dont care 3. precharge command not allowed else t ras would be violated.
44 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. timing parameters -7e -75 -8e symbol* min max min max min max units t ac (3) 5.4 5.4 6 ns t ac (2) 5.4 6 6 ns t ah 0.8 0.8 1 ns t as 1.5 1.5 2 ns t ch 2.5 2.5 3 ns t cl 2.5 2.5 3 ns t ck (3) 7 7.5 8 ns t ck (2) 7.5 10 10 ns t ckh 0.8 0.8 1 ns t cks 1.5 1.5 2 ns t cmh 0.8 0.8 1 ns t cms 1.5 1.5 2 ns t hz (3) 5.4 5.4 6 ns t hz (2) 5.4 6 7 ns t lz111ns t oh 2.7 2.7 3 ns t ras 37 120,000 44 120,000 50 120,000 ns t rc 60 66 70 ns t rcd 15 20 20 ns t rp 15 20 20 ns *cas latency indicated in parentheses. -7e -75 -8e symbol* min max min max min max units note: 1. for this example, the burst length = 1, and the cas latency = 2. 2. x16: a8, a9 and a11 = dont care x8: a9 and a11 = dont care x4: a11 = dont care 3. read command not allowed else t ras would be violated. single read C with auto precharge 1 enable auto precharge t ch t cl t ck t rp t ras t rcd cas latency t rc dqm / dqml, dqmh cke clk a0-a9, a11 dq ba0, ba1 a10 t cmh t cms t ah t as t ah t as t ah t as row row bank bank row row bank don t care undefined t hz t oh d out m t ac command t cmh t cms nop 3 read active nop nop 3 active nop t ckh t cks column m 2 t0 t1 t2 t4 t3 t5 t6 t7 t8 nop nop
45 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. alternating bank read accesses 1 timing parameters -7e -75 -8e symbol* min max min max min max units t ac (3) 5.4 5.4 6 ns t ac (2) 5.4 6 6 ns t ah 0.8 0.8 1 ns t as 1.5 1.5 2 ns t ch 2.5 2.5 3 ns t cl 2.5 2.5 3 ns t ck (3) 7 7.5 8 ns t ck (2) 7.5 10 10 ns t ckh 0.8 0.8 1 ns t cks 1.5 1.5 2 ns t cmh 0.8 0.8 1 ns t cms 1.5 1.5 2 ns t lz111ns t oh 2.7 2.7 3 ns t ras 37 120,000 44 120,000 50 120,000 ns t rc 60 66 70 ns t rcd 15 20 20 ns t rp 15 20 20 ns t rrd 14 15 20 ns enable auto precharge t ch t cl t ck t ac t lz dqm / dqml, dqmh clk a0-a9, a11 dq ba0, ba1 a10 t oh d out m t cmh t cms t ah t as t ah t as t ah t as row row row row dont care undefined t oh d out m + 3 t ac t oh t ac t oh t ac d out m + 2 d out m + 1 command t cmh t cms nop nop active nop read nop active t oh d out b t ac t ac read enable auto precharge row active row bank 0 bank 0 bank 3 bank 3 bank 0 cke t ckh t cks column m 2 column b 2 t0 t1 t2 t4 t3 t5 t6 t7 t8 t rp - bank 0 t ras - bank 0 t rcd - bank 0 t rcd - bank 0 cas latency - bank 0 t rcd - bank 3 cas latency - bank 3 t t rc - bank 0 rrd *cas latency indicated in parentheses. -7e -75 -8e symbol* min max min max min max units note: 1. for this example, the burst length = 4, and the cas latency = 2. 2. x16: a8, a9 and a11 = dont care x8: a9 and a11 = dont care x4: a11 = dont care
46 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. read C full-page burst 1 timing parameters -7e -75 -8e symbol* min max min max min max units t ac (3) 5.4 5.4 6 ns t ac (2) 5.4 6 6 ns t ah 0.8 0.8 1 ns t as 1.5 1.5 2 ns t ch 2.5 2.5 3 ns t cl 2.5 2.5 3 ns t ck (3) 7 7.5 8 ns t ck (2) 7.5 10 10 ns t ckh 0.8 0.8 1 ns t cks 1.5 1.5 2 ns t cmh 0.8 0.8 1 ns t cms 1.5 1.5 2 ns t hz (3) 5.4 5.4 6 ns t hz (2) 5.4 6 7 ns t lz111ns t oh 2.7 2.7 3 ns t rcd 15 20 20 ns t ch t cl t ck t ac t lz t rcd cas latency dqm / dqml, dqmh cke clk a0-a9, a11 dq ba0, ba1 a10 t oh d out m t cmh t cms t ah t as t ah t as t ac t oh d out m +1 row row t hz t ac t oh d out m +1 t ac t oh d out m +2 t ac t oh d out m -1 t ac t oh d out m full-page burst does not self-terminate. can use burst terminate command. ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) full page completed 3 256 (x16) locations within same row 512 (x8) locations within same row 1,024 (x4) locations within same row command t cmh t cms nop nop nop active nop read nop burst term nop nop ( ) ( ) ( ) ( ) nop ( ) ( ) ( ) ( ) t ah t as bank ( ) ( ) ( ) ( ) bank t ckh t cks ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) column m 2 t0 t1 t2 t4 t3 t5 t6 tn + 1 tn + 2 tn + 3 tn + 4 dont care undefined -7e -75 -8e symbol* min max min max min max units *cas latency indicated in parentheses. note: 1. for this example, the cas latency = 2. 2. x16: a8, a9 and a11 = dont care x8: a9 and a11 = dont care x4: a11 = dont care 3. page left open; no t rp.
47 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. read C dqm operation 1 timing parameters -7e -75 -8e symbol* min max min max min max units t ac (3) 5.4 5.4 6 ns t ac (2) 5.4 6 6 ns t ah 0.8 0.8 1 ns t as 1.5 1.5 2 ns t ch 2.5 2.5 3 ns t cl 2.5 2.5 3 ns t ck (3) 7 7.5 8 ns t ck (2) 7.5 10 10 ns t ckh 0.8 0.8 1 ns t cks 1.5 1.5 2 ns t cmh 0.8 0.8 1 ns t cms 1.5 1.5 2 ns t hz (3) 5.4 5.4 6 ns t hz (2) 5.4 6 7 ns t lz111ns t oh 2.7 2.7 3 ns t rcd 15 20 20 ns t ch t cl t ck t rcd cas latency dqm / dqml, dqmh cke clk a0-a9, a11 dq ba0, ba1 a10 t cms row bank row bank t ac lz d out m t oh d out m + 3 d out m + 2 t t hz lz t t cmh command nop nop nop active nop read nop nop nop t hz t ac t oh t ac t oh t ah t as t cms t cmh t ah t as t ah t as t ckh t cks enable auto precharge disable auto precharge column m 2 t0 t1 t2 t4 t3 t5 t6 t7 t8 dont care undefined -7e -75 -8e symbol* min max min max min max units *cas latency indicated in parentheses. note: 1. for this example, the burst length = 4, and the cas latency = 2. 2. x16: a8, a9 and a11 = dont care x8: a9 and a11 = dont care x4: a11 = dont care
48 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. write C without auto precharge 1 *cas latency indicated in parentheses. disable auto precharge all banks t ch t cl t ck t rp t ras t rcd t rc dqm / dqml, dqmh cke clk a0-a9, a11 dq ba0, ba1 a10 t cmh t cms t ah t as row row bank bank bank row row bank t wr d in m t dh t ds d in m + 1 d in m + 2 d in m + 3 command t cmh t cms nop nop nop active nop write nop precharge active t ah t as t ah t as t dh t ds t dh t ds t dh t ds single bank t ckh t cks column m 3 2 t0 t1 t2 t4 t3 t5 t6 t7 t8 dont care note: 1. for this example, the burst length = 4, and the write burst is followed by a manual precharge. 2. 15ns is required between and the precharge command, regardless of frequency. 3. x16: a8, a9 and a11 = dont care x8: a9 and a11 = dont care x4: a11 = dont care timing parameters -7e -75 -8e symbol* min max min max min max units t ah 0.8 0.8 1 ns t as 1.5 1.5 2 ns t ch 2.5 2.5 3 ns t cl 2.5 2.5 3 ns t ck (3) 7 7.5 8 ns t ck (2) 7.5 10 10 ns t ckh 0.8 0.8 1 ns t cks 1.5 1.5 2 ns t cmh 0.8 0.8 1 ns t cms 1.5 1.5 2 ns t dh 0.8 0.8 1 ns t ds 1.5 1.5 2 ns t ras 37 120,000 44 120,000 50 120,000 ns t rc 60 66 70 ns t rcd 15 20 20 ns t rp 15 20 20 ns t wr 14 15 15 ns -7e -75 -8e symbol* min max min max min max units
49 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. write C with auto precharge 1 timing parameters -7e -75 -8e symbol* min max min max min max units t ah 0.8 0.8 1 ns t as 1.5 1.5 2 ns t ch 2.5 2.5 3 ns t cl 2.5 2.5 3 ns t ck (3) 7 7.5 8 ns t ck (2) 7.5 10 10 ns t ckh 0.8 0.8 1 ns t cks 1.5 1.5 2 ns t cmh 0.8 0.8 1 ns t cms 1.5 1.5 2 ns t dh 0.8 0.8 1 ns t ds 1.5 1.5 2 ns t ras 37 120,000 44 120,000 50 120,000 ns t rc 60 66 70 ns t rcd 15 20 20 ns t rp 15 20 20 ns t wr 1 clk + 1 clk + 1 clk + C 7ns 7.5ns 7ns enable auto precharge t ch t cl t ck t rp t ras t rcd t rc dqm / dqml, dqmh cke clk a0-a9, a11 dq ba0, ba1 a10 t cmh t cms t ah t as row row bank bank row row bank t wr d in m t dh t ds d in m + 1 d in m + 2 d in m + 3 command t cmh t cms nop nop nop active nop write nop active t ah t as t ah t as t dh t ds t dh t ds t dh t ds t ckh t cks nop nop column m 2 t0 t1 t2 t4 t3 t5 t6 t7 t8 t9 dont care *cas latency indicated in parentheses. 7e -75 -8e symbol* min max min max min max units note: 1. for this example, the burst length = 4. 2. x16: a8, a9 and a11 = dont care x8: a9 and a11 = dont care x4: a11 = dont care
50 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. single write C without auto precharge 1 timing parameters -7e -75 -8e symbol* min max min max min max units t ah 0.8 0.8 1 ns t as 1.5 1.5 2 ns t ch 2.5 2.5 3 ns t cl 2.5 2.5 3 ns t ck (3) 7 7.5 8 ns t ck (2) 7.5 10 10 ns t ckh 0.8 0.8 1 ns t cks 1.5 1.5 2 ns t cmh 0.8 0.8 1 ns t cms 1.5 1.5 2 ns t dh 0.8 0.8 1 ns t ds 1.5 1.5 2 ns t ras 37 120,000 44 120,000 50 120,000 ns t rc 60 66 70 ns t rcd 15 20 20 ns t rp 15 20 20 ns t wr 14 15 15 ns *cas latency indicated in parentheses. -7e -75 -8e symbol* min max min max min max units note: 1. for this example, the burst length = 1, and the write burst is followed by a manual precharge. 2. 15ns is required between and the precharge command, regardless of frequency. 3. x16: a8, a9 and a11 = dont care x8: a9 and a11 = dont care x4: a11 = dont care 4. precharge command not allowed else t ras would be violated. disable auto precharge all banks t ch t cl t ck t rp t ras t rcd t rc dqm / dqml, dqmh cke clk a0-a9, a11 dq ba0, ba1 a10 t cmh t cms t ah t as row row bank bank bank row row bank t wr d in m t dh t ds command t cmh t cms nop 4 nop 4 precharge active nop write active nop nop t ah t as t ah t as single bank t ckh t cks column m 3 2 t0 t1 t2 t4 t3 t5 t6 t7 t8 dont care
51 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. enable auto precharge t ch t cl t ck t rp t ras t rcd t rc dqm / dqml, dqmh cke clk a0-a9, a11 dq ba0, ba1 a10 t cmh t cms t ah t as row row bank bank row row bank t wr d in m command t cmh t cms nop 3 nop 3 nop active nop 3 write nop active t ah t as t ah t as t dh t ds t ckh t cks nop nop column m 2 t0 t1 t2 t4 t3 t5 t6 t7 t8 t9 dont care single write C with auto precharge 1 timing parameters -7e -75 -8e symbol* min max min max min max units t ah 0.8 0.8 1 ns t as 1.5 1.5 2 ns t ch 2.5 2.5 3 ns t cl 2.5 2.5 3 ns t ck (3) 7 7.5 8 ns t ck (2) 7.5 10 10 ns t ckh 0.8 0.8 1 ns t cks 1.5 1.5 2 ns t cmh 0.8 0.8 1 ns t cms 1.5 1.5 2 ns t dh 0.8 0.8 1 ns t ds 1.5 1.5 2 ns t ras 37 120,000 44 120,000 50 120,000 ns t rc 60 66 70 ns t rcd 15 20 20 ns t rp 15 20 20 ns t wr 1 clk + 1 clk + 1 clk + C 7ns 7.5ns 7ns *cas latency indicated in parentheses. 7e -75 -8e symbol* min max min max min max units note: 1. for this example, the burst length = 1. 2. x16: a8, a9 and a11 = dont care x8: a9 and a11 = dont care x4: a11 = dont care 3. write command not allowed else t ras would be violated.
52 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. alternating bank write accesses 1 timing parameters 7e -75 -8e symbol* min max min max min max units t ah 0.8 0.8 1 ns t as 1.5 1.5 2 ns t ch 2.5 2.5 3 ns t cl 2.5 2.5 3 ns t ck (3) 7 7.5 8 ns t ck (2) 7.5 10 10 ns t ckh 0.8 0.8 1 ns t cks 1.5 1.5 2 ns t cmh 0.8 0.8 1 ns t cms 1.5 1.5 2 ns t dh 0.8 0.8 1 ns t ds 1.5 1.5 2 ns t ras 37 120,000 44 120,000 50 120,000 ns t rc 60 66 70 ns t rcd 15 20 20 ns t rp 15 20 20 ns t rrd 14 15 20 ns t wr 1 clk + 1 clk + 1 clk + C 7ns 7.5ns 7ns dont care t ch t cl t ck clk dq d in m t dh t ds d in m + 1 d in m + 2 d in m + 3 command t cmh t cms nop nop active nop write nop nop active t dh t ds t dh t ds t dh t ds active write d in b t dh t ds d in b + 1 d in b + 3 t dh t ds t dh t ds enable auto precharge dqm / dqml, dqmh a0-a9, a11 ba0, ba1 a10 t cmh t cms t ah t as t ah t as t ah t as row row row row enable auto precharge row row bank 0 bank 0 bank 1 bank 0 bank 1 cke t ckh t cks d in b + 2 t dh t ds column b 2 column m 2 t rp - bank 0 t ras - bank 0 t rcd - bank 0 t t rcd - bank 0 t wr - bank 0 wr - bank 1 t rcd - bank 1 t t rc - bank 0 rrd t0 t1 t2 t3 t4 t5 t6 t7 t8 t9 note: 1. for this example, the burst length = 4. 2. x16: a8, a9 and a11 = dont care x8: a9 and a11 = dont care x4: a11 = dont care -7e -75 -8e symbol* min max min max min max units *cas latency indicated in parentheses.
53 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. write C full-page burst t cks 1.5 1.5 2 ns t cmh 0.8 0.8 1 ns t cms 1.5 1.5 2 ns t dh 0.8 0.8 1 ns t ds 1.5 1.5 2 ns t rcd 15 20 20 ns timing parameters -7e -75 -8e symbol* min max min max min max units t ah 0.8 0.8 1 ns t as 1.5 1.5 2 ns t ch 2.5 2.5 3 ns t cl 2.5 2.5 3 ns t ck (3) 7 7.5 8 ns t ck (2) 7.5 10 10 ns t ckh 0.8 0.8 1 ns t ch t cl t ck t rcd dqm / dqml, dqmh cke clk a0-a9, a11 ba0, ba1 a10 t cms t ah t as t ah t as row row full-page burst does not self-terminate. can use burst terminate command to stop. 2, 3 ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) full page completed command t cmh t cms nop nop nop active nop write burst term nop nop ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) dq d in m t dh t ds d in m + 1 d in m + 2 d in m + 3 t dh t ds t dh t ds t dh t ds d in m - 1 t dh t ds t dh t ds t ah t as bank ( ) ( ) ( ) ( ) bank t cmh t ckh t cks ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) 256 (x16) locations within same row 512 (x8) locations within same row 1,024 (x4) locations within same row column m 1 t0 t1 t2 t3 t4 t5 tn + 1 tn + 2 tn + 3 dont care *cas latency indicated in parentheses. -7e -75 -8e symbol* min max min max min max units note: 1. x16: a8, a9 and a11 = dont care x8: a9 and a11 = dont care x4: a11 = dont care 2. t wr must be satisfied prior to precharge command. 3. page left open; no t rp.
54 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. write C dqm operation 1 t cks 1.5 1.5 2 ns t cmh 0.8 0.8 1 ns t cms 1.5 1.5 2 ns t dh 0.8 0.8 1 ns t ds 1.5 1.5 2 ns t rcd 15 20 20 ns timing parameters -7e -75 -8e symbol* min max min max min max units t ah 0.8 0.8 1 ns t as 1.5 1.5 2 ns t ch 2.5 2.5 3 ns t cl 2.5 2.5 3 ns t ck (3) 7 7.5 8 ns t ck (2) 7.5 10 10 ns t ckh 0.8 0.8 1 ns dont care t ch t cl t ck t rcd dqm / dqml, dqmh cke clk a0-a9, a11 dq ba0, ba1 a10 t cms t ah t as row bank row bank enable auto precharge d in m + 3 t dh t ds d in m d in m + 2 t cmh command nop nop nop active nop write nop nop t cms t cmh t dh t ds t dh t ds t ah t as t ah t as disable auto precharge t ckh t cks column m 2 t0 t1 t2 t3 t4 t5 t6 t7 *cas latency indicated in parentheses. -7e -75 -8e symbol* min max min max min max units note: 1. for this example, the burst length = 4. 2. x16: a8, a9 and a11 = dont care x8: a9 and a11 = dont care x4: a11 = dont care
55 64mb: x4, x8, x16 sdram 64mb: x4, x8, x16 sdram micron technology, inc., reserves the right to change products or specifications without notice. 64msdram.p65 C rev. 11/99 ?1999, micron technology, inc. 54-pin plastic tsop (400 mil) see detail a .20 .05 1.00 (2x) .75 (2x) .80 typ .71 10.24 7 10.08 8 .18 .13 .60 .40 pin #1 id detail a 22.30 3 22.14 4 .45 .30 1.2 max .10 .25 11.86 5 11.66 6 .80 typ .10 (2x) 2.80 9 9 note: 1. all dimensions in millimeters max or typical where noted. min 2. package width and length do not include mold protrusion; allowable mold protrusion is 0.25mm per side. 3. 22.35 for some versions. 4. 22.09 for some versions. 5. 11.96 for some versions. 6. 11.56 for some versions. 7. 10.29 for some versions. 8. 10.03 for some versions. 8000 s. federal way, p.o. box 6, boise, id 83707-0006, tel: 208-368-3900 e-mail: prodmktg@micron.com, internet: http://www.micron.com, customer comment line: 800-932-4992 micron is a registered trademark of micron technology, inc.

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