W942508AH CMOS Double Data Rate synchronous dynamic random access memo
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PRELIMINARY W942508AH BANKS SDRAM
W942508AH CMOS Double Data Rate synchronous dynamic random access memory (DDR SDRAM), organized 8,388,608 words banks bits. Using pipelined architecture 0.175 process technology, W942508AH delivers data bandwidth 286M words second (-7). fully comply with personal computer industrial standard, W942508AH sorted into three speed grades: compliant MHz/CL2.5 DDR266/CL2 specification, compliant DDR266/CL2.5 specification, compliant DDR200/CL2 specification Inputs reference positive edge (except CKE). timing reference point differential clock when signals cross during transition. Write Read data synschronized with both edges (Data Strobe). having programmable Mode Register, system change burst length, latency cycle, interleave sequential burst maximize performance. W942508AH ideal main memory high performance applications.
2.5V 0.2V Power Supply Clock Frequency Double Data Rate architecture; data transfers clock cycle
Differential clock inputs (CLK edge-aligned with data Read; center-aligned with data Write Latency: Burst Length: Auto Refresh Self Refresh Precharged Power Down Active Power-Down Write Data Mask Write Latency Refresh cycles Interface: SSTL-2 Packaged: TSOP pin, 875mil 0.65mm pitch
PARAMETERS
SYM. DESCRIPTION MIN. /MAX.
tRAS IDD1 IDD4 IDD6
CL=2 CL=2.5 Active Precharge Command Period Active Ref/Active Command Period Operation Current (Single bank) Burst Operation Current Self-Refresh Current
Clock Cycle Time
min. min. min. min. max. max. max.
110mA 165mA
110mA 155mA
100mA 150mA
Publication Release Date: 2001 Revision .0.0
W942508AH
CONFIGURATION (TOP VIEW)
VDDQ VSSQ VDDQ VSSQ VDDQ A10/AP VSSQ VDDQ VSSQ VDDQ VSSQ VREF
W942508AH
DESCRIPTION
Number 28-32,35-42 Name Function Address Description Multiplexed pins column address. address A12. Column address: (A10 used Auto Precharge) Select bank activate during address latch time, bank read/write during column address latch time. input output data synchronized with both edges DQS. Bi-directional signal. input signal during write operation output signal during read operation. Edgealigned with read data, Center-aligned with write data. Disable enable command decoder. When command decoder disabled, command ignored previous operation continues.
26,27
BS0,
Bank Select Data Input/ Output Data Strobe
2,5,8,11,56,59, 62,65
Chip Select
23,22,21 45,46
Command Inputs Command inputs (along with define command being entered. Write mask When asserted "high" burst write, input data masked. synchronized with both edges DQS.
CLK, VREF VDDQ VSSQ
Differential clock Clock inputs, inputs reference positive edge inputs (except CKE). Clock Enable Reference Voltage controls clock activation deactivation. When low, Power Down mode, Suspend mode, Self Refresh mode entered. VREF reference voltage inputs buffers.
1,18,33 34,48,66 3,9,15,55,61 6,12,52,58,64
Power +2.5V Power logic circuit inside SDRAM. Ground Ground logic circuit inside SDRAM.
Power 2.5V Separated power from VDD, used output buffer, improve buffer noise. Ground buffer Separated ground from VSS, used output buffer, improve noise.
4,7,10,13,14,16 ,17,19,20,25,43 NC1, ,50,53,54,57,60
Connection connection
Publication Release Date: 2001 Revision
W942508AH
BLOCK DIAGRAM
CLOCK BUFFER
CONTROL
SIGNAL
GENERATOR COMMAND
DECODER
DECODER
COLUMN DECODER
COLUMN DECODER DECODER
CELL ARRAY BANK
CELL ARRAY BANK
ADDRESS BUFFER
MODE REGISTER SENSE AMPLIFIER
SENSE AMPLIFIER
PREFETCH REGISTER DATA CONTROL CIRCUIT REFRESH COUNTER COLUMN COUNTER BUFFER
COLUMN DECODER DECODER DECODER
COLUMN DECODER
CELL ARRAY BANK
CELL ARRAY BANK
SENSE AMPLIFIER
SENSE AMPLIFIER
NOTE: cell array configuration 8912 1024
W942508AH
ABSOLUTE MAXIMUM RATINGS
PARAMETER Input, Output Voltage Power Supply Voltage Operating Temperature Storage Temperature Soldering Temperature (10s) Power Dissipation Short Circuit Output Current SYMBOL VIN, VOUT VDD, VDDQ TOPR TSTG TSOLDER IOUT RATING -0.3 VDDQ +0.3 -0.3 UNIT NOTES
RECOMMENDED OPERATING CONDITIONS
70°C) PARAMETER Power Supply Voltage Power Supply Voltage (for Buffer) Input reference Voltage Termination Voltage (System) Input High Voltage (DC) Input Voltage (DC) Differential Clock Input Voltage Input Differential Voltage. inputs (DC) Input High Voltage (AC) Input Voltage (AC) Input Differential Voltage. inputs (AC) Differential input Cross Point Voltage Differential Clock Middle Point (AC) VISO (AC) VDDQ/2 VDDQ/2 VDDQ/2 VDDQ/2 (AC) (AC) (AC) VREF 0.31 VREF 0.31 VDDQ 13,15 SYMBOL VDDQ VREF (DC) (DC) VICK (DC) (DC) MIN. 0.49 VDDQ VREF 0.04 VREF 0.15 -0.3 -0.3 0.36 TYP. 0.50 VDDQ VREF MAX. 0.51 VDDQ VREF 0.04 VDDQ VREF 0.15 VDDQ VDDQ UNIT NOTES 13,15
Note Undershoot Limit VIL(min) -0.9V with pulse width Overshoot Limit VIH(max) VDDQ+0.9V with pulse width VIH(DC) VIL(DC) levels maintain current logic state. VIH(AC) VIL(AC) levels change logic state.
Publication Release Date: 2001 Revision
W942508AH
CAPACITANCE
(VDD VDDQ 2.5V± 0.2V, MHz, 25°C, VOUT(DC) VDDQ/2, VOUT(Peak Peak) 0.2V) PARAMETER Input Capacitance (except pins) Input Capacitance (CLK pins) DQS, capacitance capacitance capacitance SYMBOL CCLK CI/O CNC1 CNC2 MIN. MAX. DELTA (MAX.) UNIT
Note: These parameters periodically sampled 100% tested. pins have additional capacitance adjustment adjacent capacitance. pins have Power Ground clamp.
W942508AH
CHARACTERISTICS
PARAMETER OPERATING CURRENT Bank Active-Precharge; min; min; inputs changing twice clock cycle; Address control inputs changing once clock cycle OPERATING CURRENT Bank Active-Read-Precharge; Burst=2; min; CL=2.5; min; IOUT=0mA; Address control inputs changing once clock cycle. PRECHARGE-POWER-DOWN STANDBY CURRENT Banks Idle; Power down mode; max; min; VREF IDLE FLOATING STANDBY CURRENT min; Banks Idle; min; Address other control inputs changing once clock cycle; Vref IDLE STANDBY CURRENT min; Banks Idle; min; min; Address other control inputs changing once clock cycle; IDLE QUIET STANDBY CURRENT min; Banks Idle; min; min; Address other control inputs stable; VREF ACTIVE POWER-DOWN STANDBY CURRENT Bank Active; Power down mode; max; ACTIVE STANDBY CURRENT min; min; Bank Active-Precharge; tRAS max; min; inputs changing twice clock cycle; Address other control inputs changing once clock cycle OPERATING CURRENT Burst=2; Reads; Continuous burst; Bank Active; Address control inputs changing once clock cycle; CL=2.5; min; IOUT=0mA OPERATING CURRENT Burst=2; Write; Continuous burst; Bank Active; Address control inputs changing once clock cycle; CL=2.5; min; inputs changing twice clock cycle AUTO REFRESH CURRENT tRFC SELF REFRESH CURRENT 0.2V RANDOM READ CURRENT Banks Active Read with activate every 20ns, Auto-Precharge Read every 20ns; Burst=4; tRCD= IOUT= 0mA; inputs changing twice clock cycle; Address changing once clock cycle SYM. Max. UNIT NOTES
IDD0
IDD1
IDD2P
IDD2F
IDD2N
IDD2Q
IDD3P
IDD3N
IDD4R
IDD4W
IDD5 IDD6
IDD7
Publication Release Date: 2001 Revision
W942508AH
RANDOM READ CURRENT TIMING (IDD7)
10ns
tRCD
COMMAND ADDRESS Bank READ Bank Bank READ Bank Bank READ Bank Bank READ Bank Bank
LEAKAGE OUTPUT BUFFER STRENGTH
PARAMETER Input leakage current VDDQ other pins under test Output leakage current (Output disabled, VOUT VDDQ Output High voltage (under test load condition) Output voltage (under test load condition) Output minimum source current Output minimum sink current Output minimum source current Output minimum sink current Half Strength Full Strength SYMBOL II(L) MIN. MAX. UNITS NOTES
IO(L) (DC) (DC) (DC) (DC)
0.76 -15.2 15.2 -10.4 10.4
0.76
W942508AH
CHARACTERISTICS OPERATING CONDITIONS (NOTES:
SYMBOL tRFC tRAS tRCD tRAP tCCD tRRD tDAL tDQSCK tDQSQ tRPRE tRPST tDIPW tDQSH tDQSL tDSS tDSH tWPRES tWPRE tWPST tDQSS tDSSK tIPW tT(SS) tWTR tXSNR tXSRD tREF tMRD PARAMETER Active Ref/Active Command Period Ref/Active Command Period Active Precharge Command Period Active Read/Write Command Delay Time Active Read with Auto Precharge enable Read/Write(a) Read/Write(b) Command Period Precharge Active Command Period Active(a) Active(b) Command Period Write Recovery time Auto Precharge Write Recovery Precharge time Cycle Time CL=2 CL=2.5 Data Access time from CLK, output access time from CLK, Data Strobe Edge Output Data Edge Skew Hight level width level width half period (minmum actual tCH, tCL) output data hold time from Read Preamble Time Read Postamble Time Setup Time Hold Time input pulse width (for each input) input high pulse width input pulse width falling edge setup time falling edge hold time from Clock Write Preamble Set-up Time Write Preamble Time Write Postamble Time Write command first latching transition UDQS LDQS Skew (x16) Input Setup Time Input Hold Time Control Address input pulse width (for each input) Data-out High-impedance Time from CLK, Data-out Low-impedance Time from CLK, SSTL Input Transition Internal Write Read command delay Exit Self Refresh non-Read command Exit Self Refresh Read command Refresh Time (8K) Mode Register cycle time MIN. -0.75 -0.75 0.45 0.45 (tCL,tCH) -0.75 1.75 0.35 0.35 0.25 0.75 -0.25 -0.75 -0.75 MAX. MIN. -0.75 -0.75 0.45 0.45 (tCL,tCH) -0.75 1.75 0.35 0.35 0.25 0.75 -0.25 -0.75 -0.75 MAX. MIN. -0.8 -0.8 0.45 0.45 (tCL,tCH) tHP-1.0 0.35 0.35 0.25 0.75 -0.25 -0.8 -0.8 MAX. UNITS NOTES
100000
100000
100000
0.75 0.75 0.55 0.55
0.75 0.75 0.55 0.55
0.55 0.55
1.25 0.25
1.25 0.25
1.25 0.25
0.75 0.75
0.75 0.75
Publication Release Date: 2001 Revision
W942508AH
TEST CONDITIONS
SYMBOL PARAMETER VALUE UNIT NOTE
VREF VSWING VID(AC) SLEW VOTR
Input High voltage (AC) Input voltage (AC) Input reference voltage Termination voltage Input signal peak peak swing Differential Clock Input Reference Voltage Input Difference Voltage. inputs (AC) Input signal minmum slew rate Output timing measurement refernece voltage
VREF+0.31 VREF-0.31 0.5xVDDQ 0.5xVDDQ Vx(AC) 0.5xVDDQ
V/ns
VDDQ SWING (max)
ohms 30pF
VIHmin (AC) VREF VILmax (AC)
ohms
SLEW=V IHmin(AC)V ILmax(AC)/
TEST LOAD
W942508AH
Note: Conditions outside limits listed under "ABSOLUTE MAXIMUM RATINGS" cause permanent damage
device.
voltages referenced VSS, VSSQ. Peak peak noise VREF exceed VREF(DC). VOH=1.95V,VOL=0.35V VOH=1.9V,VOL=0.4V values IOH(DC) based VDDQ=2.3V VTT=1.19V. values IOL(DC) based VDDQ=2.3V VTT=1.11V. These parameters depend cycle rate these values measured cycle rate with minimun values tRC. applied directly device. system supply signal termination resistors, expected equal VREF must track variations level VREF. These parameters depend output loading.Specified values obtained with output open.
(10) Transition times measured between min(AC) max(AC).Transition (rise fall) input signals have fixed slope. (11) result nominal calculation with regard contains more than decimal place, result rounded nearest decimal place. (i.e., tCK=7.5ns, 0.75 7.5ns 5.625ns rounded 5.6ns.) (12) differential clock cross point voltage where input timing measurement referenced. (13) magnitude difference between input level input level. (14) VISO means {VICK(CLK) VICK( )}/2. (15) Refer figure below.
VICK VID(AC) VICK VICK VICK VID(AC)
Differential
VISO VISO(min) VISO(max)
(16)
tDQSCK depend clock jitter. These timing measured stable clock.
Publication Release Date: 2001 Revision
W942508AH
OPERATION MODE
following table shows operation commands.
Simplified Truth Table (Note (2)) A12, Symbol Command Device State
CKEn1
CKEn
BS0,
A11, A9-A0
PREA WRIT WRITA READ READA EMRS AREF SELF SELEX PDEX
Bank Active Bank Precharge Precharge Write Write with Auto Read Read with Auto Mode Register Extended Operation Burst Read Stop Device Deselect Auto Refresh Self Refresh Entry Self Refresh Exit Power down mode entry Power down mode exit Data write enable Data write disable Mode
Idle
Active Active Active Active Idle Idle Active Idle Idle Idle (Self Refresh) Idle/Active
(Power Down) Active Active
Note:1. V=Valid X=Don't Care L=Low level H=High level CKEn signal input levell when commands issued. CKEn-1 signal input level clock cycle before commands issued. These state designated BS0,BS1 signals. LDM, (W942516AH) Power Down Mode entry burst cycle.
W942508AH
Function Truth Table(Note Current State Idle active Read Write
Address BS,CA,A10 BS,CA,A10 BS,RA BS,A10 Op-Code BS,CA,A10 BS,CA,A10 BS,RA BS,A10 Op-Code BS,CA,A10 BS,CA,A10 BS,RA BS,A10 Op-Code BS,CA,A10 BS,CA,A10 BS,RA BS,A10 Op-Code
Command NOP/BST READ/READ WRIT/WRIT PRE/PREA AREF/SELF MRS/EMRS NOP/BST READ/READ WRIT/WRIT PRE/PREA AREF/SELF MRS/EMRS READ/READ WRIT/WRIT PRE/PREA AREF/SELF MRS/EMRS READ/READ WRIT/WRIT PRE/PREA AREF/SELF MRS/EMRS ILLEGAL ILLEGAL activating
Action
Notes
Refresh Self refresh Mode register accessing Begin read: Determine Begin write: Determine ILLEGAL Precharge ILLEGAL ILLEGAL Continue burst Continue burst Burst stop Term burst, read: Determine ILLEGAL ILLEGAL Term burst, precharging ILLEGAL ILLEGAL Continue burst Continue burst ILLEGAL Term burst, start read: Determine Term burst, start read: Determine ILLEGAL Term burst. precharging ILLEGAL ILLEGAL
Publication Release Date: 2001 Revision
W942508AH
Current State Read with auto prechange
Address BS,CA,A10 BS,CA,A10 BS,RA BS,A10 Op-Code BS,CA,A10 BS,CA,A10 BS,RA BS,A10 Op-Code BS,CA,A10 BS,CA,A10 BS,RA BS,A10 Op-Code BS,CA,A10 BS,CA,A10 BS,RA BS,A10 Op-Code
Command
Action Continue burst Continue burst ILLEGAL ILLEGAL ILLEGAL ILLEGAL ILLEGAL ILLEGAL ILLEGAL Continue burst Continue burst ILLEGAL ILLEGAL ILLEGAL ILLEGAL ILLEGAL ILLEGAL ILLEGAL Nop-> Idle after Nop-> Idle after ILLEGAL ILLEGAL ILLEGAL ILLEGAL ILLEGAL ILLEGAL ILLEGAL Nop-> active after tRCD Nop-> active after tRCD ILLEGAL ILLEGAL ILLEGAL ILLEGAL ILLEGAL ILLEGAL ILLEGAL
Notes
READ/READA WRIT/WRITA PRE/PREA AREF/SELF MRS/EMRS READ/READA WRIT/WRITA PRE/PREA AREF/SELF MRS/EMRS READ/READA WRIT/WRITA PRE/PREA AREF/SELF MRS/EMRS READ/READA WRIT/WRITA PRE/PREA AREF/SELF MRS/EMRS
Write with auto precharge
Precharging
activating
W942508AH
Current State Write recovering
Address BS,CA,A BS,CA,A BS,RA BS,A10 Op-Code BS,CA,A BS,CA,A BS,RA BS,A10 Op-Code
Command
Action Nop->dle after Nop->Idle after ILLEGAL ILLEGAL ILLEGAL ILLEGAL ILLEGAL ILLEGAL ILLEGAL Nop->Enter precharge after Nop->Enter precharge after ILLEGAL ILLEGAL ILLEGAL ILLEGAL ILLEGAL ILLEGAL ILLEGAL Nop->Idle after Nop->Idle after ILLEGAL ILLEGAL ILLEGAL ILLEGAL Nop->Row after tMRD Nop->Row after tMRD ILLEGAL ILLEGAL ILLEGAL
Notes
READ/READA WRIT/WRITA PRE/PREA AREF/SELF MRS/EMRS READ/READA WRIT/WRITA PRE/PREA AREF/SELF MRS/EMRS READ/WRIT ACT/PRE/PREA AREF/SELF/MRS/EMRS READ/WRIT ACT/PRE/PREA/AREF/S
Write recovering with auto precharge
Refreshing
Mode register accessing
Note: entries assume that active (High level) during preceding clock cycle current clock cycle. Illegal bandk idle. Illegal bank specified states; Function legal bank indicated Bank Address (BS), depending state that bank. Illegal tRCD satisfied. Illegal tRAS satisfied. Must satisifty burst interrupt condition. Must avoid contention, turn around, and/or satisfy write recovery requirements. Must mask preceding data which don't satisfy
Remark: High level, level, High level (Don't care), V=Valid data
Publication Release Date: 2001 Revision
W942508AH
Function Truth Table Current State Self refresh Power Down banks idle Active state other than listed above
Address INVALID
Action
Notes
Exit Self Refresh->Idle after tXSNR Exit Self Refresh->Idle after tXSNR ILLEGAL ILLEGAL Maintain Self Refresh INVALID Enter Power down->Idle after Maintain power down mode Refer Function Truth Table Enter Power down Enter Power down Self Refresh ILLEGAL ILLEGAL Power down Refer Function Truth Table Enter Power down Enter Power down ILLEGAL ILLEGAL ILLEGAL Power down Refer Function Truth Table
Note: Self refresh enter only from banks idle state. Power down enter only from bank idle active state.
Remark: High level, level, High level (Don't care), V=Valid data
W942508AH
SIMPLIFIED STATE DIAGRAM
SELF REFRESH
SREF SREFX
IDLE
MRS/EMRS
MODE REGISTER
AREF
AUTO REFRESH
PDEX
ACTIVE POWERDOWN POWER DOWN
PDEX
ACTIVE
Read Read
Write
Write
Read
Write Read
Write Write
Read Read Read
Write
Read
POWER APPLIED
POWER
CHARGE
Automatic Sequence Command Sequence
Publication Release Date: 2001 Revision
W942508AH
FUNCTIONAL DESCRIPTION
Power Sequence
Apply power attempt state( 0.2V) (all other inputs undefined) Apply before same time VDDQ. Apply VDDQ before same time VREF.
Start Clock maintain stable condition 200µs(min). After stable power clock, apply take high. Issue EMRS (Extended Mode Register Set) enable establish Output Driver Type. Issue (Mode Register Set) reset device idle with additional cycles(min) clock required Lock)
Issue precharge command banks device. Issue more Auto Refresh commands. Issue MRS-Initialize device operation. device operation mode sequence sequence skipped.)
Command Function
Bank Activate command ="L", ="H", ="H", BS0, BS1=Bank, A12=Row Address) Bank Activate command activates bank designated (Bank address) signal. addresses latched when this command issued cell data read sense amplifiers. maximum time that each bank held active state specified tRAS (max). After this command issued, Read Write operation executed. Bank Precharge command ="L", ="H", ="L", BS0, BS1=Bank, A10="L", A11, A12=Don't care) Bank Precharge command percharges bank designated precharged bank switched from active state idle state. Precharge command ="L", ="H", ="L", BS0, BS1=Don't care, A10="H", A11, A12= Don't care) Precharge command precharges banks simultaneously. Then banks switched idle state. Write command ="H", ="L", ="L", BS0, BS1=Bank, A10="L", A11=Column Address) write command performs Write operation bank designated write data latched both edges DQS. length write data (Burst Length) column access sequence (Addressing Mode) must Mode Register power-up prior Write operation. Write with Auto Precharge command
W942508AH
="H", ="L", ="L", BS0, BS1=Bank, A10="H", A11=Column Address) Write with Auto Precharge command performs Precharge operation automatically after Write operation. This command must interrupted other commands. Read command ="H", ="L", ="H", BS0, BS1=Bank, A10="L", A11=Column Address) Read command performs Read operation bank designated read data synchronized with both edges DQS. length read data (Burst Length), Addressing Mode Latency (access time from command clock cycle) must programmed Mode Register power-up prior Read operation. Read with Auto Precharge command ="H", ="L", ="H", BS0, BS1=Bank, A10="H", A11=Column Address) Read with Auto precharge command automatically performs Precharge operation after Read operation. READA tRAS (min) (BL/2) Internal precharge operation begins after BL/2 cycle from Read with Auto Precharge command. tRCD(min) READA tRAS(min) (BL/2) Data read with shortest latency, internal Precharge operation does begin until after tRAS (min) completed. This command must interrupted other command. Mode Register command ="L", ="L", ="L", BS0="L", BS1="L", A12=Register Data) Mode Register command programs values latency, Addressing Mode, Burst Length reset Mode Register. default values Mode Register after powerup undefined, therefore this command must issued during power-up sequence. Also, this command issued while banks idle state. Refer table specific codes. Extended Mode Register command ="L", ="L", ="L", BS0="H", BS1="L", A12=Register data) Extended Mode Register command implemented needed function extensions standard (SDR-SDRAM). Currently only available mode EMRS enable/disable, decoded default value extended mode register defined; therefore this command must issued during power-up sequence enabling DLL. Refer table specific codes. 2-10 No-Operation command ="H", ="H", ="H") No-Operation command simply performs operation (same command Device Deselect). 2-11 Burst Read stop command Publication Release Date: 2001 Revision
W942508AH
="H", ="H", ="L") Burst stop command used stop burst operation. This command only valid during Burst Read operation. 2-12 Device Deselect command ="H") Device Deselect command disables command decoder that Address inputs ignored. This command similar No-Operation command. 2-13 Auto Refresh command ="L", ="L", ="H", CKE="L", BS0, BS1, A12=Don't care) Auto Refresh command used refresh address provided internal refresh counter. Refresh operation must performed 8192 times within 64ms. next command issued after tREF from Auto Refresh command. When Auto Refresh command used, banks must idle state. 2-14 Self Refresh Entry command ="L", ="L", ="H", CKE="L", BS0, BS1, A12=don't care) Self Refresh Entry command used enter Self Refresh mode. While device Self Refresh mode, input output buffer (except buffer) disabled Refresh operation automatically performed. Self Refresh mode exited taking "high" (the Self Refresh Exit command). During self refresh, DLLl disable. 2-15 Self Refresh Exit command (CKE="L", ="H" CKE="H", ="H", ="H") This command used exit from Self Refresh mode. subsequent commands issued after tXSNR (tXSRD Read Command) from this command. 2-16 Data Write Enable /Disable command (DM="L/H" LDM, UDM="L/H") During Write cycle, LDM, signal functions Data Mask control every word input data. signal controls signal controls DQ15.
Read Operation
Issuing Bank Activate command idle bank puts into active state. When Read command issued after tRCD from Bank Activate command, data read sequentially, synchronized with both edges (Burst Read operation). initial read data becomes available after latency from issuing Read command. latency must Mode Register power-up. When Precharge Operation performed bank during Burst Read operation, Burst operation terminated. When Read with Auto Precharge command issued, Precharge operation performed automatically after Read cycle, then bank switched idle state. This command cannot interrupted other commands. Refer diagrams Read operation.
W942508AH
Write Operation
Issuing Write command after tRCD from bank activate command. input data latched sequentially, synchronizing with both edges(rising &falling) after Write command (Burst write operation). burst length Write data (Burst Length) Addressing Mode must Mode Register power-up. When Precharge operation performed bank during Burst Write operation, Burst operation terminated. When Write with Auto Precharge command issued, Precharge operation performed automatically after Write cycle, then bank switched idle state, Write with Auto Precharge command cannot interrupted other command entire burst data duration. Refer diagrams Write operation.
Precharge
There Commands, which perform precharge operation (Bank Precharge Precharge All). When Bank Precharge command issued active bank, bank precharged then switched idle state. Bank Precharge command precharge bank independently other bank hold unprecharged bank active state. maximum time each bank held active state specified tRAS (max). Therefore, each bank must precharged within tRAS(max) from bank activate command. Precharge command used precharge banks simultaneously. Even banks active state, Precharge command still issued. this case, Precharge operation performed only active bank precharge bank then switched idle state.
Burst Termination
When Precharge command used bank Burst cycle, Burst operation terminated. When Burst Read cycle interrupted Precharge command, read operation disabled after clock cycle latency) from Precharge command. When Burst Write cycle interrupted Precharge command input circuit reset same clock cycle which precharge command issued. this case, signal must asserted "high: during prevent writing invalided data cell array. When Burst Read Stop command issued bank Burst Read cycle, Burst Read operation terminated. Burst read Stop command supported during write burst operation. Refer diagrams Burst termination.
Refresh Operation
types Refresh operation performed device: Auto Refresh Self Refresh. repeating Auto Refresh cycle, each bank turn refreshed automatically. Refresh operation must performed 8912 times(rows)within 64ms. period between Auto Refresh command next command specified tRFC. Self Refresh mode enter issuing Self Refresh command (CKE asserted "low"). while banks idle state. device Self Refresh mode long held "low". case 8192 burst Auto Refresh commands, 8192 burst Auto Refresh commands must performed within 7.8us before entering after exiting Self Refresh mode. case distributed Auto Refresh commands, distributed auto refresh commands must issued every 7.8us last distributed Publication Release Date: 2001 Revision
W942508AH
Auto Refresh commands must performed within 7.8us before entering self refresh mode. After exiting from Self Refresh mode, refresh operation must performed within 7.8us. Self Refresh mode, input/output buffers disable, resulting lower power dissipation (except buffer). Refer diagrams Refresh operation.
Power Down Mode
types Power Down Mode performed device: Active Standby Power Down Mode Precharge Standby Power Down Mode. When device enters Power Down Mode, input/output buffers disabled resulting power dissipation (except buffer). Power Down Mode enter asserting "low" while device running burst cycle. Taking :high" exit this mode. When goes high, operation command must input next rising edge. Refer diagrams Power Down Mode.
W942508AH
Mode Register Operation
mode register programmed Mode Register command (MRS/EMRS) when banks idle state. data Mode Register transferred using BS0, address inputs. Mode Register designates operation mode read write cycle. register divided into five filed: Burst Length field length burst data Addressing Mode selected designate column access sequence Burst cycle Latency field assess time clock cycle reset field reset Regular/Extended Mode Register filed select type (Regular/Extended MRS). EMRS cycle implemented extended function (DLL enable/Disable mode) initial value Mode Register (including EMRS) after power undefined; therefore Mode Register command must issued before power operation. Burst Length field This field specifies data length column access using pins sets Burst Length words. Addressing Mode Select (A3) Addressing Mode modes; Interleave mode Sequential Mode, When "0", Sequential mode selected. When "1", Interleave mode selected. Both addressing Mode support burst length words. Addressing mode Sequential Interleave Burst Length Reserved words words words Reserved
Publication Release Date: 2001 Revision
W942508AH
Address sequence Sequential mode column access performed incrementing column address input device. address varied Burst Length following. Addressing Sequence Sequential Mode DATA Data Data Data Data Data Data Data Data ACCESS ADDRESS words(address bits carried from BURST LENGTH words (address bits carried from words (address carried from
Addressing sequence Interleave mode Column access started from inputted column address performed interleaving address bits sequence shown following. Address Sequence Interleave Mode DATA Data Data Data Data Data Data Data Data ACCESS ADDRESS words words BURST LENGTH words
W942508AH
Latency field This field specifies number clock cycles from assertion Read command first data read. minimum values Latency depends frequency CLK. Reset (A8) This used reset DLL. When "1", reset. Mode Register /Extended Mode register change bits (BS0, BS1) These bits used select MRS/EMRS. A12-A0 Regular cycle Extended cycle Reserved Extended Mode Register field Switch field (A0) This used select enable disable Output Driver Size Control field (A1) This used select Output Driver Size, both Full strength Half strength based JEDEC standard. Reserved field Test mode entry (A7) This used enter Test mode must normal operation. Reserved bits (A9, A10, A11, A12) These bits reserved future operations. They must normal operation. Output driver Full strength Half strength Enable Disable Latency Reserved Reserved Reserved Reserved Reserved Reserved
Publication Release Date: 2001 Revision
W942508AH
PACKAGE DIMENSION
TSOP
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