M12L128168A-6BIG - Elite Semiconductor Memory Technology, Inc.

ESMT M12L128168A

Operation temperature condition -40

°

C ~85

°

C

Elite Semiconductor Memo ry Technology Inc. Publication Date: Oct. 2007

Revision: 1.2 1/43

SDRAM 2M x 16 Bit x 4 Banks

Synchronous DRAM

FEATURES

y JEDEC standard 3.3V power supply

y LVTTL compatible with multiplexed address

y Four banks operation

y MRS cycle with address key programs

- CAS Latency ( 2 & 3 )

- Burst Length ( 1, 2, 4, 8 & full page )

- Burst Type ( Sequential & Interleave )

y All inputs are sampled at the positive going edge of the

system clock

y Burst Read single write operation

y DQM for masking

y Auto & self refresh

y 64ms refresh period (4K cycle)

ORDERING INFORMATION

PRODUCT NO. MAX FREQ. PACKAGE COMMENTS

M12L128168A-5TIG 200MHz TSOP II Pb-free

M12L128168A-5BIG 200MHz BGA Pb-free

M12L128168A-6TIG 166MHz TSOP II Pb-free

M12L128168A-6BIG 166MHz BGA Pb-free

M12L128168A-7TIG 143MHz TSOP II Pb-free

M12L128168A-7BIG 143MHz BGA Pb-free

GENERAL DESCRIPTION

The M12L128168A is 134,217,728 bits synchronous high data rate Dynamic RAM organized as 4 x 2,097,152 words by 16 bits.

Synchronous design allows precise cycle control with the use of system clock I/O transactions are possible on every clock cycle.

Range of operating frequencies, programmable burst length and programmable latencies allow the same device to be useful for a

variety of high bandwidth, high performance memory system applications.

Pin Arrangement (Top View)

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

VDD

DQ0

VDDQ

DQ1

DQ2

VSSQ

DQ3

DQ4

VDDQ

DQ5

DQ6

VSSQ

DQ7

VDD

LDQM

WE

CAS

RAS

CS

A13

A12

A10/AP

A0

A1

A2

A3

VDD

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

VDDQ

DQ12

DQ11

VSSQ

DQ10

DQ9

VDDQ

DQ8

VSS

NC

UDQM

CLK

CKE

NC

A11

A9

A8

A7

A6

A5

A4

VSS

VSS DQ15

DQ14 DQ13

DQ12 DQ11

DQ10 DQ 9

DQ8 NC

UDQM CLK

NC A11

A8 A7

VSS A5

VDDQ DQ0

VSSQ DQ2

VDDQ DQ4

VDD LDQM

CAS RAS

A13 A12

A0 A1

A3 A2

123456789

A

B

C

D

E

F

G

H

J

VSSQ

VDDQ

VSSQ

VDDQ

VSS

CKE

A9

A6

A4

VDD

DQ1

DQ3

DQ7

WE

CS

A10

VDD

VSSQ DQ6 DQ5

ESMT M12L128168A

Operation temperature condition -40

°

C ~85

°

C

Elite Semiconductor Memo ry Technology Inc. Publication Date: Oct. 2007

Revision: 1.2 2/43

BLOCK DIAGRAM

PIN DESCRIPTION

PIN NAME INPUT FUNCTION

CLK System Clock Active on the positive going edge to sample all inputs

CS Chip Select

Disables or enables device operation by masking or enabling all

inputs except CLK , CKE and L(U)DQM

CKE Clock Enable

Masks system clock to freeze operation from the next clock cycle.

CKE should be enabled at least one cycle prior new command.

Disable input buffers for power down in standby.

A0 ~ A11 Address Row / column address are multiplexed on the same pins.

Row address : RA0~RA11, column address : CA0~CA8

A12 , A13 Bank Select Address Selects bank to be activated during row address latch time.

Selects bank for read / write during column address latch time.

RAS Row Address Strobe Latches row addresses on the positive going edge of the CLK with

RAS low. (Enables row access & precharge.)

CAS Column Address Strobe

Latches column address on the positive going edge of the CLK with

CAS low. (Enables column access.)

WE Write Enable Enables write operation and row precharge.

Latches data in starting from CAS , WE active.

L(U)DQM Data Input / Output Mask Makes data output Hi-Z, tSHZ after the clock and masks the output.

Blocks data input when L(U)DQM active.

DQ0 ~ DQ15 Data Input / Output Data inputs / outputs are multiplexed on the same pins.

V

DD / VSS Power Supply / Ground Power and ground for the input buffers and the core logic.

V

DDQ / VSSQ Data Output Power / Ground Isolated power supply and ground for the output buffers to provide

improved noise immunity.

N.C No Connection This pin is recommended to be left No Connection on the device.

L(U)DQM

DQ

Mode

Register

Control Logic

Column

Address

Buffer

&

Counte

r

Row

Address

Buffer

&

Refresh

Counter

Bank D

Row Decoder

Bank A

Bank B

Bank C

Sense Amplifier

Column Decoder

Data Control Circuit

Latch Circuit

Input & Output

Buffer

Address

Clock

Generator

CLK

CKE

Command Decoder

CS

RAS

CAS

WE

ESMT M12L128168A

Operation temperature condition -40

°

C ~85

°

C

Elite Semiconductor Memo ry Technology Inc. Publication Date: Oct. 2007

Revision: 1.2 3/43

ABSOLUTE MAXIMUM RATINGS

Parameter Symbol Value Unit

Voltage on any pin relative to VSS V

IN, VOUT -1.0 ~ 4.6 V

Voltage on VDD supply relative to VSS V

DD, VDDQ -1.0 ~ 4.6 V

Storage temperature TSTG -55 ~ +150 C°

Power dissipation PD 1 W

Short circuit current IOS 50 mA

Note : Permanent device damage may occur if ABSOLUTE MAXIMUM RATING are exceeded.

Functional operation should be restricted to recommended operating condition.

Exposure to higher than recommended voltage for extended periods of time could affect device reliability.

DC OPERATING CONDITION

Recommended operating conditions (Voltage referenced to VSS = 0V, TA = -40 to 85 C°)

Parameter Symbol Min Typ Max Unit Note

Supply voltage VDD, VDDQ 3.0 3.3 3.6 V

Input logic high voltage VIH 2.0 3.0 VDD+0.3 V 1

Input logic low voltage VIL -0.3 0 0.8 V 2

Output logic high voltage VOH 2.4 - - V IOH = -2mA

Output logic low voltage VOL - - 0.4 V IOL = 2mA

Input leakage current IIL -5 - 5 μA 3

Output leakage current IOL -5 - 5 μA 4

Note: 1. VIH(max) = 4.6V AC for pulse width ≤ 10ns acceptable.

2. VIL(min) = -1.5V AC for pulse width ≤ 10ns acceptable.

3. Any input 0V ≤ V

IN

≤

V

DD + 0.3V, all other pins are not under test = 0V.

4. Dout is disabled , 0V

≤

VOUT ≤ V

DD.

CAPACITANCE (VDD = 3.3V, TA = 25 C°, f = 1MHZ)

Parameter Symbol Min Max Unit

Input capacitance (A0 ~ A11, A13 ~ A12) CIN1 2.5 4 pF

Input capacitance

(CLK, CKE, CS , RAS , CAS , WE & L(U)DQM)

CIN2 2.5 4 pF

Data input/output capacitance (DQ0 ~ DQ15) COUT 2 6.5 pF

ESMT M12L128168A

Operation temperature condition -40

°

C ~85

°

C

Elite Semiconductor Memo ry Technology Inc. Publication Date: Oct. 2007

Revision: 1.2 4/43

DC CHARACTERISTICS

Recommended operating condition unless otherwise noted，TA = -40 to 85 C°

Version

Parameter Symbol Test Condition CAS

Latency -5 -6 -7

Unit Note

Operating Current

(One Bank Active) I

CC1 Burst Length = 1, tRC ≥tRC(min), IOL = 0 mA 170 160 140 mA 1,2

I

CC2P CKE ≤VIL(max), tcc = tCK(MIN) 2

Precharge Standby Current

in powe

r

-down mode I

CC2PS CKE & CLK

≤

VIL (max), tCC =

∞

2

mA

I

CC2N CKE ≥VIH(min), CS ≥ V

IH(min), tCC = tCK(MIN)

Input signals are changed one time during 2tck

45

Precharge Standby Current

in non power-down mode

I

CC2NS CKE ≥VIH(min), CLK

≤

VIL(max), tcc =

∞

input signals are stable 25

mA

I

CC3P CKE ≤VIL(max), tCC = tCK(MIN) 6

Active Standby Current

in powe

r

-down mode I

CC3PS CKE & CLK

≤

VIL(max), tCC =

∞

6

mA

I

CC3N

CKE ≥VIH(min), CS ≥ VIH(min), tCC=15ns

Input signals are changed one time during 2clks

All other pins ≥ V

DD-0.2V or ≤ 0.2V

55 mA

Active Standby Cu

r

rent

in non powe

r

-down mode

(One Bank Active)

I

CC3NS CKE ≥VIH(min), CLK

≤

VIL(max), tCC =

∞

input signals are stable 35 mA

Operating Current

(Burst Mode) I

CC4 I

OL = 0 mA, Page Burst, 2 Banks activated 280 210 180 mA 1,2

Refresh Current ICC5 tRC ≥tRC(min) 280 210 180 mA

Self Refresh Current ICC6 CKE

≤

0.2V 2 mA

Note : 1. Measured with outputs open.

2. Input signals are changed one time during 2 CLKS.

ESMT M12L128168A

Operation temperature condition -40

°

C ~85

°

C

Elite Semiconductor Memo ry Technology Inc. Publication Date: Oct. 2007

Revision: 1.2 5/43

AC OPERATING TEST CONDITIONS (VDD = 3.3V

±

0.3V，TA = -40 to 85 C°)

Parameter Value Unit

Input levels (Vih/Vil) 2.4/0.4 V

Input timing measurement reference level 1.4 V

Input rise and fall-time tr/tf = 1/1 ns

Output timing measurement reference level 1.4 V

Output load condition See Fig. 2

(Fig. 1) DC Output Load Circuit (Fig. 2) AC Output Load Circuit

OPERATING AC PARAMETER

(AC operating conditions unless otherwise noted)

Version

Parameter Symbol

-5 -6 -7

Unit Note

Row active to row active delay tRRD(min) 10 12 14

ns 1

RAS to CAS delay t

RCD(min) 15 18 20

ns 1

Row precharge time tRP(min) 15 18 20

ns 1

t

RAS(min) 38 40 42

ns 1

Row active time

t

RAS(max) 100 us

@ Operating t

RC(min) 53 58 63

ns 1

Row cycle time

@ Auto refresh tRFC(min) 55 60 70

ns 1,5

Last data in to col. address delay tCDL(min) 1 tCK 2

Last data in to row precharge tRDL(min) 2 tCK 2

Last data in to burst stop tBDL(min) 1 tCK 2

Refresh period (4,096 rows) tREF(max) 64 ms 6

Output

870

VOH (DC) =2.4V , IOH = -2 mA

VOL (DC) =0.4V , IOL = 2 mA Output

50pF

Z0 =50

50pF

50

Vtt = 1.4V

3.3V

1200 Ω

Ω

ESMT M12L128168A

Operation temperature condition -40

°

C ~85

°

C

Elite Semiconductor Memo ry Technology Inc. Publication Date: Oct. 2007

Revision: 1.2 6/43

Version

Parameter Symbol

-5 -6 -7

Unit Note

Col. address to col. address delay tCCD(min) 1 tCK 3

CAS latency = 3 2

Number of valid

Output data CAS latency = 2 1

ea 4

Note : 1. The minimum number of clock cycles is determined by dividing the minimum time required with clock cycle time and then

rounding off to the next higher integer.

2. Minimum delay is required to complete write.

3. All parts allow every cycle column address change.

4. In case of row precharge interrupt, auto precharge and read burst stop.

5. A new command may be given tRFC after self refresh exit.

6. A maximum of eight consecutive AUTO REFRESH commands (with tRFCmin) can be posted to any given SDRAM, and the

maximum absolute interval between any AUTO REFRESH command and the next AUTO REFRESH command is

8x15.6 μs.)

AC CHARACTERISTICS (AC operating condition unless otherwise noted)

-5 -6 -7

Parameter Symbol MIN MAX MIN MAX MIN MAX Unit Note

CAS latency = 3 5 6 7

CLK cycle time

CAS latency = 2

tCC

10

1000

10

1000

10

1000 ns 1

CAS latency = 3 4.5 5.4 5.4

CLK to valid

output delay CAS latency = 2 tSAC 6 6 6 ns 1,2

CAS latency = 3 2 2.5 2.5

Output data

hold time CAS latency = 2 tOH 2 2.5 2.5 ns 2

CLK high pulsh width tCH 2 2.5 2.5 ns 3

CLK low pulsh width tCL 2 2.5 2.5 ns 3

Input setup time tSS 1.5 1.5 1.5 ns 3

Input hold time tSH 1 1 1 ns 3

CLK to output in Low-Z tSLZ 1 1 1 ns 2

CAS latency = 3 4.5 5.4 5.4

CLK to output

in Hi-Z CAS latency = 2

tSHZ

6 6 6

ns -

Note : 1. Parameters depend on programmed CAS latency.

2. If clock rising time is longer than 1ns. (tr/2 - 0.5) ns should be considered.

3. Assumed input rise and fall time (tr & tf) =1ns.

If tr & tf is longer than 1ns. transient time compensation should be considered.

i.e., [(tr + tf)/2 – 1] ns should be added to the parameter.

ESMT M12L128168A

Operation temperature condition -40

°

C ~85

°

C

Elite Semiconductor Memo ry Technology Inc. Publication Date: Oct. 2007

Revision: 1.2 7/43

SIMPLIFIED TRUTH TABLE

COMMAND CKEn-1 CKEn CS RAS CAS WE DQM A13

A12 A10/AP A11

A9~A0 Note

Register Mode Register set H X L L L L X OP CODE 1,2

Auto Refresh H 3

Entry H L L L L H X X 3

L H H H X 3

Refresh Self

Refresh Exit L H H X X X X X 3

Bank Active & Row Addr. H X L L H H X V Row Address

Auto Precharge Disable L 4

Read &

Column Address Auto Precharge Enable

H X L H L H X V

H

Column

Address

(A0~A8) 4,5

Auto Precharge Disable L 4

Write &

Column Address Auto Precharge Enable

H X L H L L X V

H

Column

Address

(A0~A8) 4,5

Burst Stop H X L H H L X X 6

Bank Selection V L

Precharge

All Banks

H X L L H L X

X H

X

H X X X

Entry H L

L V V V

X

Clock Suspend or

Active Power Down

Exit L H X X X X X

X

H X X X

Entry H L

L H H H

X

H X X X

Precharge Power Down Mode

Exit L H

L V V V

X

DQM H X V X 7

H X X X

No Operating Command H X

L H H H

X X

(V = Valid , X = Don’t Care. H = Logic High , L = Logic Low )

Note : 1.OP Code : Operating Code

A0~A11 & A13~A12 : Program keys. (@ MRS)

2.MRS can be issued only at all banks precharge state.

A new command can be issued after 2 CLK cycles of MRS.

3.Auto refresh functions are as same as CBR refresh of DRAM.

The automatical precharge without row precharge of command is meant by “Auto”.

Auto/self refresh can be issued only at all banks idle state.

4.A13~A12 : Bank select addresses.

If A13 and A12 are “Low” at read ,write , row active and precharge ,bank A is selected.

If A13 is “Low” and A12 is “High” at read ,write , row active and precharge ,bank B is selected.

If A13 is “High” and A12 is “Low” at read ,write , row active and precharge ,bank C is selected.

If A13 and A12 are “High” at read ,write , row active and precharge ,bank D is selected

If A10/AP is “High” at row precharge , A13 and A12 is ignored and all banks are selected.

5.During burst read or write with auto precharge. new read/write command can not be issued.

Another bank read/write command can be issued after the end of burst.

New row active of the associated bank can be issued at tRP after the end of burst.

6.Burst stop command is valid at every burst length.

7.DQM sampled at positive going edge of a CLK and masks the data-in at the very CLK (write DQM latency is 0), but

makes Hi-Z state the data-out of 2 CLK cycles after.(Read DQM latency is 2)

ESMT M12L128168A

Operation temperature condition -40

°

C ~85

°

C

Elite Semiconductor Memo ry Technology Inc. Publication Date: Oct. 2007

Revision: 1.2 8/43

MODE REGISTER FIELD TABLE TO PROGRAM MODES

Register Programmed with MRS

Address A13~A12 A11~A10/AP A9 A8 A7 A6 A5 A4 A3 A2 A1 A0

Function RFU RFU W.B.L. TM CAS Latency BT Burst Length

Test Mode CAS Latency Burst Type Burst Length

A8 A7 Type A6 A5 A4 Latency A3 Type A2 A1 A0 BT = 0 BT = 1

0 0 Mode Register Set 0 0 0 Reserved 0 Sequential 0 0 0 1 1

0 1 Reserved 0 0 1 Reserved 1 Interleave 0 0 1 2 2

1 0 Reserved 0 1 0 2 0 1 0 4 4

1 1 Reserved 0 1 1 3

0 1 1 8 8

1 0 0 Reserved 1 0 0 Reserved Reserved

1 0 1 Reserved 1 0 1 Reserved Reserved

1 1 0 Reserved 1 1 0 Reserved Reserved

1 1 1 Reserved

1 1 1 Full Page Reserved

Full Page Length : 512

POWER UP SEQUENCE

1.Apply power and start clock, Attempt to maintain CKE = ”H”, DQM = ”H” and the other pin are NOP condition at the inputs.

2. Maintain stable power , stable clock and NOP input condition for a minimum of 200us.

3. Issue precharge commands for all banks of the devices.

4. Issue 2 or more auto-refresh commands.

5. Issue mode register set command to initialize the mode register.

cf.) Sequence of 4 & 5 is regardless of the order.

The device is now ready for normal operation.

Note : 1. RFU(Reserved for future use) should stay “0” during MRS cycle.

2. If A9 is high during MRS cycle, “ Burst Read single write” function will be enabled.

ESMT M12L128168A

Operation temperature condition -40

°

C ~85

°

C

Elite Semiconductor Memo ry Technology Inc. Publication Date: Oct. 2007

Revision: 1.2 9/43

BURST SEQUENCE (BURST LENGTH = 4)

Initial Adrress

A1 A0 Sequential Interleave

0 0 0 1 2 3 0 1 2 3

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

BURST SEQUENCE (BURST LENGTH = 8)

Initial

A2 A1 A0 Sequential Interleave

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

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

ESMT M12L128168A

Operation temperature condition -40

°

C ~85

°

C

Elite Semiconductor Memo ry Technology Inc. Publication Date: Oct. 2007

Revision: 1.2 10/43

DEVICE OPERATIONS

CLOCK (CLK)

The clock input is used as the reference for all SDRAM

operations. All operations are synchronized to the positive

going edge of the clock. The clock transitions must be

monotonic between VIL and VIH. During operation with CKE

high all inputs are assumed to be in valid state (low or high) for

the duration of setup and hold time around positive edge of the

clock for proper functionality and Icc specifications.

CLOCK ENABLE(CKE)

The clock enable (CKE) gates the clock onto SDRAM. If CKE

goes low synchronously with clock (set-up and hold time same

as other inputs), the internal clock suspended from the next

clock cycle and the state of output and burst address is frozen

as long as the CKE remains low. All other inputs are ignored

from the next clock cycle after CKE goes low. When all banks

are in the idle state and CKE goes low synchronously with

clock, the SDRAM enters the power down mode from the next

clock cycle. The SDRAM remains in the power down mode

ignoring the other inputs as long as CKE remains low. The

power down exit is synchronous as the internal clock is

suspended. When CKE goes high at least “1CLK + tSS” before

the high going edge of the clock, then the SDRAM becomes

active from the same clock edge accepting all the input

commands.

BANK ADDRESSES (A13~A12)

This SDRAM is organized as four independent banks of

2,097,152 words x 16 bits memory arrays. The A13~A12

inputs are latched at the time of assertion of RAS and CAS

to select the bank to be used for the operation. The banks

addressed A13~A12 are latched at bank active, read, write,

mode register set and precharge operations.

ADDRESS INPUTS (A0 ~ A11)

The 21 address bits are required to decode the 2,097,152

word locations are multiplexed into 12 address input pins

(A0~A11). The 12 row addresses are latched along with RAS

and A13~A12 during bank active command. The 9 bit column

addresses are latched along with CAS , WE and A13~A12

during read or with command.

NOP and DEVICE DESELECT

When RAS , CAS and WE are high , The SDRAM

performs no operation (NOP). NOP does not initiate any new

operation, but is needed to complete operations which require

more than single clock cycle like bank activate, burst read,

auto refresh, etc. The device deselect is also a NOP and is

entered by asserting CS high. CS high disables the

command decoder so that RAS , CAS , WE and all the

address inputs are ignored.

POWER-UP

1.Apply power and start clock, Attempt to maintain CKE =

“H”, DQM = “H” and the other pins are NOP condition at

the inputs.

2.Maintain stable power, stable clock and NOP input

condition for minimum of 200us.

3.Issue precharge commands for both banks of the

devices.

4.Issue 2 or more auto-refresh commands.

5.Issue a mode register set command to initialize the

mode register.

cf.) Sequence of 4 & 5 is regardless of the order.

The device is now ready for normal operation.

MODE REGISTER SET (MRS)

The mode register stores the data for controlling the

various operating modes of SDRAM. It programs the CAS

latency, burst type, burst length, test mode and various

vendor specific options to make SDRAM useful for variety

of different applications. The default value of the mode

register is not defined, therefore the mode register must

be written after power up to operate the SDRAM. The

mode register is written by asserting low on CS , RAS ,

CAS and WE (The SDRAM should be in active mode

with CKE already high prior to writing the mode register).

The state of address pins A0~A11 and A13~A12 in the

same cycle as CS , RAS , CAS and WE going low is

the data written in the mode register. Two clock cycles is

required to complete the write in the mode register. The

mode register contents can be changed using the same

command and clock cycle requirements during operation

as long as all banks are in the idle state. The mode

register is divided into various fields into depending on

functionality. The burst length field uses A0~A2, burst type

uses A3, CAS latency (read latency from column address)

use A4~A6, vendor specific options or test mode use

A7~A8, A10/AP~A11 and A13~A12. The write burst length

is programmed using A9. A7~A8, A10/AP~A11 and

A13~A12 must be set to low for normal SDRAM

operation. Refer to the table for specific codes for various

burst length, burst type and CAS latencies.

BANK ACTIVATE

The bank activate command is used to select a random

row in an idle bank. By asserting low on RAS and CS

with desired row and bank address, a row access is

initiated. The read or write operation can occur after a

time delay of tRCD(min) from the time of bank activation. tRCD

is the internal timing parameter of SDRAM, therefore it is

dependent on operating clock frequency. The minimum

number of clock cycles required between bank activate

and read or write command should be calculated by

ESMT M12L128168A

Operation temperature condition -40

°

C ~85

°

C

Elite Semiconductor Memo ry Technology Inc. Publication Date: Oct. 2007

Revision: 1.2 11/43

DEVICE OPERATIONS (Continued)

dividing tRCD(min) with cycle time of the clock and then rounding

of the result to the next higher integer. The SDRAM has four

internal banks in the same chip and shares part of the internal

circuitry to reduce chip area, therefore it restricts the activation

of four banks simultaneously. Also the noise generated during

sensing of each bank of SDRAM is high requiring some time

for power supplies to recover before another bank can be

sensed reliably. tRRD(min) specifies the minimum time required

between activating different bank. The number of clock cycles

required between different bank activation must be calculated

similar to tRCD specification. The minimum time required for the

bank to be active to initiate sensing and restoring the complete

row of dynamic cells is determined by tRAS(min). Every SDRAM

bank activate command must satisfy tRAS(min) specification

before a precharge command to that active bank can be

asserted. The maximum time any bank can be in the active

state is determined by tRAS (max) and tRAS(max) can be

calculated similar to tRCD specification.

BURST READ

The burst read command is used to access burst of data on

consecutive clock cycles from an active row in an active bank.

The burst read command is issued by asserting low on CS

and RAS with WE being high on the positive edge of the

clock. The bank must be active for at least tRCD(min) before the

burst read command is issued. The first output appears in CAS

latency number of clock cycles after the issue of burst read

command. The burst length, burst sequence and latency from

the burst read command is determined by the mode register

which is already programmed. The burst read can be initiated

on any column address of the active row. The address wraps

around if the initial address does not start from a boundary

such that number of outputs from each I/O are equal to the

burst length programmed in the mode register. The output

goes into high-impedance at the end of burst, unless a new

burst read was initiated to keep the data output gapless. The

burst read can be terminated by issuing another burst read or

burst write in the same bank or the other active bank or a

precharge command to the same bank. The burst stop

command is valid at every page burst length.

BURST WRITE

The burst write command is similar to burst read command

and is used to write data into the SDRAM on consecutive clock

cycles in adjacent addresses depending on burst length and

burst sequence. By asserting low on CS , CAS and WE

with valid column address, a write burst is initiated. The data

inputs are provided for the initial address in the same clock

cycle as the burst write command. The input buffer is

deselected at the end of the burst length, even though the

internal writing can be completed yet. The writing can be

complete by issuing a burst read and DQM for blocking data

inputs or burst write in the same or another active bank. The

burst stop command is valid at every burst length. The write

burst can also be terminated by using DQM for blocking data

and precharge the bank tRDL after the last data input to be

written into the active row. See DQM OPERATION also.

DQM OPERATION

The DQM is used mask input and output operations. It

works similar to OE during operation and inhibits writing

during write operation. The read latency is two cycles from

DQM and zero cycle for write, which means DQM masking

occurs two cycles later in read cycle and occurs in the

same cycle during write cycle. DQM operation is

synchronous with the clock. The DQM signal is important

during burst interrupts of write with read or precharge in

the SDRAM. Due to asynchronous nature of the internal

write, the DQM operation is critical to avoid unwanted or

incomplete writes when the complete burst write is

required. Please refer to DQM timing diagram also.

PRECHARGE

The precharge is performed on an active bank by

asserting low on clock cycles required between bank

activate and clock cycles required between bank activate

and CS , RAS , WE and A10/AP with valid A13~A12 of

the bank to be procharged. The precharge command can

be asserted anytime after tRAS(min) is satisfy from the bank

active command in the desired bank. tRP is defined as the

minimum number of clock cycles required to complete row

precharge is calculated by dividing tRP with clock cycle

time and rounding up to the next higher integer. Care

should be taken to make sure that burst write is

completed or DQM is used to inhibit writing before

precharge command is asserted. The maximum time any

bank can be active is specified by tRAS(max). Therefore,

each bank has to be precharge with tRAS(max) from the

bank activate command. At the end of precharge, the

bank enters the idle state and is ready to be activated

again. Entry to power-down, Auto refresh, Self refresh and

Mode register set etc. is possible only when all banks are

in idle state.

AUTO PRECHARGE

The precharge operation can also be performed by using

auto precharge. The SDRAM internally generates the

timing to satisfy tRAS(min) and “tRP” for the programmed burst

length and CAS latency. The auto precharge command is

issued at the same time as burst write by asserting high on

A10/AP, the bank is precharge command is asserted.

Once auto precharge command is given, no new

commands are possible to that particular bank until the

bank achieves idle state.

FOUR BANKS PRECH ARGE

Four banks can be precharged at the same time by using

Precharge all command. Asserting low on CS , RAS ,

and WE with high on A10/AP after all banks have

satisfied tRAS(min) requirement, performs precharge on all

banks. At the end of tRP after performing precharge all, all

banks are in idle state.

ESMT M12L128168A

Operation temperature condition -40

°

C ~85

°

C

Elite Semiconductor Memo ry Technology Inc. Publication Date: Oct. 2007

Revision: 1.2 12/43

DEVICE OPERATIONS (Continued)

AUTO REFRESH

The storage cells of SDRAM need to be refreshed every 64ms

to maintain data. An auto refresh cycle accomplishes refresh of

a single row of storage cells. The internal counter increments

automatically on every auto refresh cycle to refresh all the

rows. An auto refresh command is issued by asserting low on

CS , RAS and CAS with high on CKE and WE . The auto

refresh command can only be asserted with all banks being in

idle state and the device is not in power down mode (CKE is

high in the previous cycle). The time required to complete the

auto refresh operation is specified by tRFC(min). The minimum

number of clock cycles required can be calculated by driving

tRFC with clock cycle time and them rounding up to the next

higher integer. The auto refresh command must be followed by

NOP’s until the auto refresh operation is completed. The auto

refresh is the preferred refresh mode when the SDRAM is

being used for normal data transactions. The auto refresh

cycle can be performed once in 15.6us.

SELF REFRESH

The self refresh is another refresh mode available in the

SDRAM. The self refresh is the preferred refresh mode for

data retention and low power operation of SDRAM. In self

refresh mode, the SDRAM disables the internal clock and

all the input buffers except CKE. The refresh addressing

and timing is internally generated to reduce power

consumption.

The self refresh mode is entered from all banks idle state

by asserting low on CS , RAS , CAS and CKE with

high on WE . Once the self refresh mode is entered, only

CKE state being low matters, all the other inputs including

clock are ignored to remain in the refresh.

The self refresh is exited by restarting the external clock

and then asserting high on CKE. This must be followed by

NOP’s for a minimum time of tRFC before the SDRAM

reaches idle state to begin normal operation. It is

recommended to use burst 4096 auto refresh cycles

immediately before and after self refresh.

ESMT M12L128168A

Operation temperature condition -40

°

C ~85

°

C

Elite Semiconductor Memo ry Technology Inc. Publication Date: Oct. 2007

Revision: 1.2 13/43

COMMANDS

Mode register set command

(CS , RAS , CAS , WE = Low)

The M12L128168A has a mode register that defines how the device operates. In

this command, A0 through A13 are the data input pins. After power on, the mode

register set command must be executed to initialize the device.

The mode register can be set only when all banks are in idle state.

During 2CLK following this command, the M12L128168A cannot accept any

other commands.

Activate command

(CS , RAS = Low, CAS , WE = High)

The M12L128168A has four banks, each with 4,096 rows.

This command activates the bank selected by A12 and A13 (BS) and a row

address selected by A0 through A11.

This command corresponds to a conventional DRAM’s RAS falling.

Precharge command

(CS , RAS , WE = Low, CAS = High )

This command begins precharge operation of the bank selected by A12 and A13

(BS). When A10 is High, all banks are precharged, regardless of A12 and A13. When

A10 is Low, only the bank selected by A12 and A13 is precharged.

After this command, the M12L128168A can’t accept the activate command to the

precharging bank during tRP (precharge to activate command period).

This command corresponds to a conventional DRAM’s RAS rising.

CLK

CKE

CS

RAS

WE

A12, A13

(Bank select)

A10

Add

CAS

H

Row

Fig. 1 Mode register set

command

Fig. 2 Row address strobe and

bank active command

CLK

CKE

CS

RAS

WE

A12, A13

(Bank select)

A10

(Precharge select)

Add

CAS

H

Fig. 3 Precharge command

ESMT M12L128168A

Operation temperature condition -40

°

C ~85

°

C

Elite Semiconductor Memo ry Technology Inc. Publication Date: Oct. 2007

Revision: 1.2 14/43

Write command

(

CS , CAS , WE = Low, RAS = High)

If the mode register is in the burst write mode, this command sets the burst start

address given by the column address to begin the burst write operation. The first

write data in burst can be input with this command with subsequent data on following

clocks.

Read command

(CS , CAS = Low, RAS , WE = High)

Read data is available after CAS latency requirements have been met.

This command sets the burst start address given by the column address.

CBR (auto) refresh command

(

CS , RAS , CAS = Low, WE , CKE = High)

This command is a request to begin the CBR refresh operation. The refresh

address is generated internally.

Before executing CBR refresh, all banks must be precharged.

After this cycle, all banks will be in the idle (precharged) state and ready for a

row activate command.

During tRC period (from refresh command to refresh or activate command), the

M12L128168A cannot accept any other command.

CLK

CKE

CS

RAS

WE

A12, A13

(Bank select)

A12, A13

(Bank select)

A10

Add

CAS

H

Col.

Fig. 4 Column address and

write command

Fig. 5 Column address and

read command

CLK

CKE

CS

RAS

WE

A12, A13

(Bank select)

A10

Add

CAS

H

Fig. 6 Auto refresh command

Col.

ESMT M12L128168A

Operation temperature condition -40

°

C ~85

°

C

Elite Semiconductor Memo ry Technology Inc. Publication Date: Oct. 2007

Revision: 1.2 15/43

Self refresh entry command

(

CS , RAS , CAS , CKE = Low , WE = High)

After the command execution, self refresh operation continues while CKE

remains low. When CKE goes to high, the M12L128168A exits the self refresh mode.

During self refresh mode, refresh interval and refresh operation are performed

internally, so there is no need for external control.

Before executing self refresh, all banks must be precharged.

Burst stop command

(

CS , WE = Low, RAS , CAS = High)

This command terminates the current burst operation.

Burst stop is valid at every burst length.

No operation

(

CS = Low , RAS , CAS , WE = High)

This command is not a execution command. No operations begin or terminate by

this command.

CLK

CKE

CS

RAS

WE

A12, A13

(Bank select)

A10

Add

CAS

CLK

CKE

CS

RAS

WE

A12, A13

(Bank select)

A10

Add

CAS

H

Fig. 7 Self refresh entry

command

Fig. 8 Burst stop command

CLK

CKE

CS

RAS

WE

A12, A13

(Bank select)

A10

Add

CAS

H

Fig. 9 No operation

ESMT M12L128168A

Operation temperature condition -40

°

C ~85

°

C

Elite Semiconductor Memo ry Technology Inc. Publication Date: Oct. 2007

Revision: 1.2 16/43

BASIC FEATURE AND FUNCTION DESCRIPTIONS

1. CLOCK Suspend

2. DQM Operation

*Note : 1. CKE to CLK disable/enable = 1CLK.

2. DQM masks data out Hi-Z after 2CLKs which should masked by CKE ”L”.

3. DQM masks both data-in and data-out.

CLK

CMD

DQM

DQ(CL2)

DQ(CL3)

RD

Q0 Q2 Q3

Q1 Q2 Q3D0 D1 D3

D1 D3

D0

WR

Masked by DQM

CLK

CMD

DQM

DQ(CL2)

DQ(CL3)

CKE

RD

Q0 Q2 Q4

Hi-Z Hi-Z Hi- Z Q6 Q7 Q8

Q5 Q6 Q7

Q1 Q3

Hi-Z Hi-Z Hi-Z

Hi-Z

1)Write Mask (BL=4) 2)Read Mask (BL=4)

DQM to Data-in Mask=0 DQM to Data-out Mask=2

3)DQM with clcok su spended (Full Page Read )

*Note2

Internal

CLK

CMD

CKE

Internal

CLK

DQ(CL2)

DQ(CL3)

RD

Q2

Q0 Q1 Q3

Q2 Q0

Q1 Q3

D0 D1 D2 D3

D1 D2 D3

D0

WR

Masked by CKE

1) Clock Suspended During Write (BL=4) 2) Clock Suspended During Read (BL=4)

Not Written Suspended Dout

ESMT M12L128168A

Operation temperature condition -40

°

C ~85

°

C

Elite Semiconductor Memo ry Technology Inc. Publication Date: Oct. 2007

Revision: 1.2 17/43

3. CAS Interrupt (I)

CLK

CMD

ADD

DQ(CL2)

DQ(CL3)

RD

QB0 QB2QA0

CLK

CMD

ADD

DQ

WR

DA0 DB0 DB1

RD

AB

QB1 QB3

QB0 QB2

QA0 QB3QB1

tCCD

*Not e 2

WR

tCC D * No t e 2

AB

tCDL

*Note 3

WR RD

tCCD *Note 2

A B

DA0 DB0 DB1

tCDL

*Note 3

DA0 DB0 DB1

DQ(CL3)

DQ (C L2 )

1)Read interrupted by Read (BL=4)

2) Wr i te i n ter ru pte d b y W ri te (B L= 2) 3 )W ri te in ter rup ted by R ead (B L=2 )

*No

t

e1

*Note : 1. By “interrupt” is meant to stop burst read/write by external before the end of burst.

By ” CAS interrupt ”, to stop burst read/write by CAS access ; read and write.

2. tCCD : CAS to CAS delay. (=1CLK)

3. tCDL : Last data in to new column address delay. (=1CLK)

ESMT M12L128168A

Operation temperature condition -40

°

C ~85

°

C

Elite Semiconductor Memo ry Technology Inc. Publication Date: Oct. 2007

Revision: 1.2 18/43

4. CAS Interrupt (II) : Read Interrupted by Write & DQM

CLK

i)CMD

DQM

DQ D1 D3

D0 D2

WR

ii)CMD

DQM

DQ

iii)CMD

DQM

DQ

iv)CMD

DQM

DQ

D1 D3

D0 D2

RD WR

D1 D3D0 D2

RD WR

Hi-Z

Q0

*Note1

Hi-Z

(a)CL=2,BL=4

RD

ESMT M12L128168A

Operation temperature condition -40

°

C ~85

°

C

Elite Semiconductor Memo ry Technology Inc. Publication Date: Oct. 2007

Revision: 1.2 19/43

*Note : 1. To prevent bus contention, there should be at least one gap between data in and data out.

5. Write Interrupted by Precharge & DQM

*Note : 1. To prevent bus contention, DQM should be issued which makes at least one gap between data in and data out.

2. To inhibit invalid write, DQM should be issued.

3. This precharge command and burst write command should be of the same bank, otherwise it is not precharge interrupt

but only another bank precharge of four banks operation.

CLK

i)CMD

ii)CMD

iii)CMD

iv)CMD

DQM

DQ

D1 D3

D1

D0 D2

D3

D0 D2

WR

(b)CL=3,BL=4

RD WR

D1 D3

D0 D2

D1 D3

D0 D2

RD WR

Hi-Z

D1 D3

D0 D2

Q0

*Note1

v)CMD

DQM

DQ

RD WR

Hi-Z

RD

CLK

CMD

DQM

DQ D1

WR

*N ote3

*

Masked by DQM

D3

t

RDL(min)

PRE

Note2

D0D2

ESMT M12L128168A

Operation temperature condition -40

°

C ~85

°

C

Elite Semiconductor Memo ry Technology Inc. Publication Date: Oct. 2007

Revision: 1.2 20/43

6. Precharge

.

7. Auto Precharge

*Note : 1. tRDL : Last data in to row precharge delay.

2. Number of valid output data after row precharge : 1,2 for CAS Latency = 2,3 respectively.

3. The row active command of the precharge bank can be issued after tRP from this point.

The new read/write command of other activated bank can be issued from this point.

At burst read/write with auto precharge, CAS interrupt of the same/another bank is illegal.

CLK

CMD

DQ D0 D1 D2 D3

WR

tRDL

*Note1

CLK

CMD

DQ(CL2) Q0 Q1 Q2 Q3

RD PRE

DQ(CL3) Q0 Q1 Q2 Q3

PRE

1)No

r

mal W

r

ite (BL=4) 2)Normal Read (BL=4)

CL=2

PRE CL=3

*Note2

CLK

CMD

DQ D0 D1 D2 D3

WR

CLK

CMD

DQ(CL2) D0 D1 D2 D3

RD

DQ(CL3)

*Note3

Auto Precharge starts

D0 D1 D2 D3

*Note3

Auto Precharge starts

1

)

No

r

mal W

r

ite

(

BL=4

)

2

)

No

r

mal Read

(

BL=4

)

tRDL (min)

ESMT M12L128168A

Operation temperature condition -40

°

C ~85

°

C

Elite Semiconductor Memo ry Technology Inc. Publication Date: Oct. 2007

Revision: 1.2 21/43

8. Burst Stop & Interrupted by Precharge

9. MRS

*Note: 1. tBDL : 1 CLK ; Last data in to burst stop delay.

Read or write burst stop command is valid at every burst length.

2. Number of valid output data after burst stop : 1,2 for CAS latency = 2,3 respectiviely.

3. Write burst is terminated. tBDL determinates the last data write.

4. DQM asserted to prevent corruption of locations D2 and D3.

5. Precharge can be issued here or earlier (satisfying tRAS min delay) with DQM.

6. PRE : All banks precharge, if necessary.

MRS can be issued only at all banks precharge state.

CLK

CMD PRE

*Note4

MRS ACT

tRP 2CLK

1)Mode Register Set

CLK

CMD

DQ(CL2)

DQ(CL3)

CLK

CMD

DQM

DQ D0 D1 D2 D3

WR STOP

*Note1

Q0 Q1

RD STOP

*Note2

1)Wri

t

eBurs

t

S

t

o

p

(BL=8)

2)Read Burst Stop (BL=4)

D5D4

CLK

CMD

DQ(CL3)

CLK

CMD

DQM

DQ D0 D1 Mask Mask

WR

Q0 Q1

RD PRE

1)Wri

t

ein

t

erru

p

t

ed

b

y

p

re

c

harge (BL=4)

2)Read interrupted by precharge (BL=4)

*Note2

PRE

*Note4

*Note3

DQ(CL2)

*Note5

Q2

Q1 Q2 Q3

Q0

t

RDL

t

BDL

Q3

ESMT M12L128168A

Operation temperature condition -40

°

C ~85

°

C

Elite Semiconductor Memo ry Technology Inc. Publication Date: Oct. 2007

Revision: 1.2 22/43

10. Clock Suspend Exit & Power Down Exit

11. Auto Refresh & Self Refresh

*Note : 1. Active power down : one or more banks active state.

2. Precharge power down : all banks precharge state.

3. The auto refresh is the same as CBR refresh of conventional DRAM.

No precharge commands are required after auto refresh command.

During tRFC from auto refresh command, any other command can not be accepted.

4. Before executing auto/self refresh command, all banks must be idle state.

5. MRS, Bank Active, Auto/Self Refresh, Power Down Mode Entry.

6. During self refresh entry, refresh interval and refresh operation are performed internally.

After self refresh entry, self refresh mode is kept while CKE is low.

During self refresh entry, all inputs expect CKE will be don’t cared, and outputs will be in Hi-Z state.

For the time interval of tRFC from self refresh exit command, any other command can not be accepted.

Before/After self refresh mode, burst auto refresh (4096 cycles) is recommended.

CLK

CKE

Internal

CLK

CMD RD

tSS

*Note1

CLK

CKE

Internal

CLK

CMD ACT

tSS

*Note2

NOP

1)Clock Suspend(=

A

ctive Powe

r

Down)Exit 2)Powe

r

Down (=P

r

echa

r

ge Powe

r

Down)

CLK

CMD PRE AR

CKE

CMD

t

RP

t

RFC

*Note5

*Note4

CLK

CMD PRE SR

CKE

CMD

t

RP

t

RFC

*Note4

1)Auto Refresh & Self Refresh

2)Self Refresh

*No

t

e3

*Note6