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256M GDDR SDRAM

K4D553238F-GC

- 1 -

Rev 1.3 (Mar. 2005)

256Mbit GDDR SDRAM

Revision 1.3

March 2005

Samsung Electronics reserves the right to change products or specification without notice.

INFORMATION IN THIS DOCUMENT IS PROVIDED IN RELATION TO SAMSUNG PRODUCTS,
AND IS SUBJECT TO CHANGE WITHOUT NOTICE.

NOTHING IN THIS DOCUMENT SHALL BE CONSTRUED AS GRANTING ANY LICENSE,
EXPRESS OR IMPLIED, BY ESTOPPEL OR OTHERWISE,

TO ANY INTELLECTUAL PROPERTY RIGHTS IN SAMSUNG PRODUCTS OR TECHNOLOGY. ALL
INFORMATION IN THIS DOCUMENT IS PROVIDED

ON AS "AS IS" BASIS WITHOUT GUARANTEE OR WARRANTY OF ANY KIND.

1. For updates or additional information about Samsung products, contact your nearest Samsung office.

2. Samsung products are not intended for use in life support, critical care, medical, safety equipment, or similar

applications where Product failure could result in loss of life or personal or physical harm, or any military or
defense application, or any governmental procurement to which special terms or provisions may apply.

256M GDDR SDRAM

K4D553238F-GC

- 3 -

Rev 1.3 (Mar. 2005)

The K4D553238F is 268,435,456 bits of hyper synchronous data rate Dynamic RAM organized as 4 x 2,097,152 words by

32 bits, fabricated with SAMSUNG

s high performance CMOS technology. Synchronous features with Data Strobe allow

extremely high performance up to 2.8GB/s/chip. I/O transactions are possible on both edges of the clock cycle. Range of

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

of high performance memory system applications.

· 2.5V ± 5% power supply for device operation

· 2.5V ± 5% power supply for I/O interface

· SSTL_2 compatible inputs/outputs

· 4 banks operation

· MRS cycle with address key programs

-. Read latency 4, 5 and 6 (clock)

-. Burst length (2, 4 and 8)

-. Burst type (sequential & interleave)

· All inputs except data & DM are sampled at the positive

going edge of the system clock

· Differential clock input

GENERAL DESCRIPTION

FEATURES

· No Wrtie-Interrupted by Read Function

· 4 DQS's ( 1DQS / Byte )

· Data I/O transactions on both edges of Data strobe

· DLL aligns DQ and DQS transitions with Clock transition

· Edge aligned data & data strobe output

· Center aligned data & data strobe input

· DM for write masking only

· Auto & Self refresh

· 32ms refresh period (4K cycle)

· 144-Ball FBGA

· Maximum clock frequency up to 350MHz

· Maximum data rate up to 700Mbps/pin

FOR 2M x 32Bit x 4 Bank DDR SDRAM

2M x 32Bit x 4 Banks Graphic Double Data Rate Synchronous DRAM
with Bi-directional Data Strobe and DLL

ORDERING INFORMATION

* K4D553238F-VC is the Lead Free package part number.

Part NO.

Max Freq.

Max Data Rate

Interface

Package

K4D553238F-GC2A

350MHz

700Mbps/pin

SSTL_2

144-Ball FBGA

K4D553238F-GC33

300MHz

600Mbps/pin

K4D553238F-GC36

275MHz

550Mbps/pin

256M GDDR SDRAM

K4D553238F-GC

- 4 -

Rev 1.3 (Mar. 2005)

PIN CONFIGURATION

(Top View)

PIN DESCRIPTION

CK,CK

Differential Clock Input

, BA

Bank Select Address

CKE

Clock Enable

Address Input

Chip Select

~ DQ

Data Input/Output

RAS

Row Address Strobe

Power

CAS

Column Address Strobe

Ground

Write Enable

DDQ

Power for DQ

DQS

Data Strobe

SSQ

Ground for DQ

Data Mask

No Connection

RFU

Reserved for Future Use

MCL

Must Connect Low

DQS0

VSS

RFU

Thermal

VSS

Thermal

VSS

Thermal

VSS

Thermal

VSS

Thermal

VSS

Thermal

VSS

Thermal

VSS

Thermal

VSS

Thermal

VSS

Thermal

VSS

Thermal

VSS

Thermal

VSS

Thermal

VSS

Thermal

VSS

Thermal

VSS

Thermal

VSSQ

VSS

RFU

DQ4

DQ6

DQ7

DQ17

DQ19

DQS2

DQ21

DQ22

CAS

RAS

DM0

VDDQ

DQ5

VDDQ

DQ16

DQ18

DM2

DQ20

DQ23

VDD

VDDQ

VDD

BA0

BA1

DQ3

VDDQ

DQ31

DQ1

A10

VDD

DQ2

VDDQ

VDD

A11

DQ0

VDDQ

VDD

DQ29

DQ30

DQ28

VDDQ

VSS

VDDQ

VDD

A8/AP

DM3

VDDQ

DQ26

VDDQ

DQ15

DQ13

DM1

DQ11

DQ9

CKE

DQS3

DQ27

DQ25

DQ24

DQ14

DQ12

DQS1

DQ10

DQ8

VREF

NOTE:
1. RFU1 is reserved for A12
2. RFU2 is reserved for BA2
3. VSS Thermal balls are optional

MCL

256M GDDR SDRAM

K4D553238F-GC

- 5 -

Rev 1.3 (Mar. 2005)

INPUT/OUTPUT FUNCTIONAL DESCRIPTION

*1 : The timing reference point for the differential clocking is the cross point of CK and CK.
For any applications using the single ended clocking, apply V

REF

to CK pin.

Symbol

Type

Function

CK, CK*1

Input

The differential system clock Input.
All of the inputs are sampled on the rising edge of the clock except
DQ

s and DM

s that are sampled on both edges of the DQS.

CKE

Input

Activates the CK signal when high and deactivates the CK signal
when low. By deactivating the clock, CKE low indicates the Power
down mode or Self refresh mode.

Input

CS enables the command decoder when low and disabled the com-
mand decoder when high. When the command decoder is disabled,
new commands are ignored but previous operations continue.

RAS

Input

Latches row addresses on the positive going edge of the CK with
RAS low. Enables row access & precharge.

CAS

Input

Latches column addresses on the positive going edge of the CK with
CAS low. Enables column access.

Input

Enables write operation and row precharge.
Latches data in starting from CAS, WE active.

DQS

~ DQS

Input/Output

Data input and output are synchronized with both edge of DQS.
DQS

for DQ

~ DQ

DQS

for DQ

~ DQ

15,

DQS

for DQ

~ DQ

23,

DQS

for DQ

~ DQ

31.

~ DM

Input

Data In mask. Data In is masked by DM Latency=0 when DM is high
in burst write. DM

for DQ

~ DQ

for DQ

~ DQ

15,

for

~ DQ

23,

for DQ

~ DQ

31.

~ DQ

Input/Output

Data inputs/Outputs are multiplexed on the same pins.

, BA

Input

Selects which bank is to be active.

~ A

Input

Row/Column addresses are multiplexed on the same pins.
Row addresses : RA

~ RA

, Column addresses : CA

~ CA

, CA

Column address CA

is used for auto precharge.

Power Supply

Power and ground for the input buffers and core logic.

DDQ

SSQ

Power Supply

Isolated power supply and ground for the output buffers to provide
improved noise immunity.

REF

Power Supply

Reference voltage for inputs, used for SSTL interface.

NC/RFU

No connection/
Reserved for future use

This pin is recommended to be left "No connection" on the device

MCL

Must Connect Low

Must connect low

256M GDDR SDRAM

K4D553238F-GC

- 6 -

Rev 1.3 (Mar. 2005)

BLOCK DIAGRAM

(1Mbit x 32I/O x 4 Bank)

Bank Select

Timing Register

Address Re

gister

Refresh Counter

Row

Buf

f
er

Row Decoder

Col.

u
f
f
er

Data Input Register

Serial to parallel

2Mx32

Sense AMP

2-bit pre

f
etch

Output Buf

f
er

I/O Control

Column Decoder

Latency & Burst Length

Programming Register

t
robe

Gen.

CK,CK

ADDR

LCKE

CK,CK

CKE

RAS

CAS

DMi

LDMi

CK,CK

LCAS

LRAS LCBR

LWE

LWCBR

LRAS

LCBR

CK, CK

LWE

LDMi

x32

DQi

Data Strobe

Intput Buffer

DLL

(DQS0~DQS3)

256M GDDR SDRAM

K4D553238F-GC

- 7 -

Rev 1.3 (Mar. 2005)

· Power-Up Sequence

DDR SDRAMs must be powered up and initialized in a predefined manner to prevent undefined operations.

1. Apply power and keep CKE at low state (All other inputs may be undefined)
- Apply VDD before VDDQ .
- Apply VDDQ before VREF & VTT
2. Start clock and maintain stable condition for minimum 200us.
3. The minimum of 200us after stable power and clock(CK,CK ), apply NOP and take CKE to be high .
4. Issue precharge command for all banks of the device.
5. Issue a EMRS command to enable DLL

(Minimum 20 clock cycles are recommended prior to MRS command, however not mandatory just in case tMRD met)

6. Issue a MRS command to reset DLL. The additional 200 clock cycles are required to lock the DLL.

1,2

7. Issue precharge command for all banks of the device.

8. Issue at least 2 or more auto-refresh commands.
9. Issue a mode register set command with A8 to low to initialize the mode register.

*1 The additional 200cycles of clock input is required to lock the DLL after enabling DLL.
*2 Sequence of 6&7 is regardless of the order

FUNCTIONAL DESCRIPTION

Power up & Initialization Sequence

Command

tRP

tMRD

precharge

ALL Banks

2nd Auto

Refresh

Mode

Any

Command

RFC

1st Auto

Refresh

RFC

EMRS

MRS

tMRD.

DLL Reset

precharge

ALL Banks

Inputs must be

stable for 200us

200 Clock min.

tMRD

CK,CK

* When the operating frequency is changed, DLL reset should be required again.

After DLL reset again, the minimum 200 cycles of clock input is needed to lock the DLL.

256M GDDR SDRAM

K4D553238F-GC

- 8 -

Rev 1.3 (Mar. 2005)

The mode register stores the data for controlling the various operating modes of DDR SDRAM. It programs CAS latency,

addressing mode, burst length, test mode, DLL reset and various vendor specific options to make DDR 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 EMRS setting for proper operation. The mode register is written by asserting low on CS, RAS, CAS and
WE(The DDR SDRAM should be in active mode with CKE already high prior to writing into the mode register). The state of
address pins A

~ A

and BA

, BA

in the same cycle as CS, RAS, CAS and WE going low is written in the mode register.

Minimum two clock cycles are requested to complete the write operation 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 depending on functionality. The burst length uses A

~ A

addressing mode uses A

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

~ A

. A

is used for test mode. A

used for DLL reset. A

, BA

and BA

must be set to low for normal MRS operation. Refer to the table for specific codes

for various burst length, addressing modes and CAS latencies.

MODE REGISTER SET(MRS)

Address Bus

Mode Register

CAS Latency

Latency

Reserved

Burst Length

Burst Type

Sequential

Interleave

Reserved

Burst Type

Type

Sequential

Interleave

* RFU(Reserved for future use)

should stay "0" during MRS
cycle.

MRS Cycle

Command

*1 : MRS can be issued only at all banks precharge state.
*2 : Minimum

is required to issue MRS command.

CK, CK

Precharge

NOP

MRS

NOP

Any

NOP

All Banks

Command

MRD

=4 t

RFU

DLL

CAS Latency

Burst Length

~ A

MRS

EMRS

DLL

DLL Reset

Yes

Test Mode

mode

Normal

Test

NOP

256M GDDR SDRAM

K4D553238F-GC

- 9 -

Rev 1.3 (Mar. 2005)

The extended mode register stores the data for enabling or disabling DLL and selecting output driver

strength. The default value of the extended mode register is not defined, therefore the extened mode register
must be written after power up for enabling or disabling DLL. The extended mode register is written by assert-
ing low on CS, RAS, CAS, WE and high on BA0(The DDR SDRAM should be in all bank precharge with CKE
already high prior to writing into the extended mode register). The state of address pins A0, A2 ~ A5, A7 ~ A11
and BA1 in the same cycle as CS, RAS, CAS and WE going low are written in the extended mode register. A1
and A6 are used for setting driver strength to normal, weak or matched impedance. Two clock cycles are
required to complete the write operation in the extended 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. A0 is used for DLL enable or disable. "High" on BA0 is used for EMRS. All the other address
pins except A0,A1,A6 and BA0 must be set to low for proper EMRS operation. Refer to the table for specific
codes.

DLL Enable

Enable

Disable

~ A

MRS

EMRS

Figure 7. Extended Mode Register set

EXTENDED MODE REGISTER SET(EMRS)

Address Bus

Extended

*1 : RFU(Reserved for future use) should stay "0" during EMRS cycle.

Output Driver Impedence Control

N/A

Do not use

Weak

60%

N/A

Do not use

Full

100%

RFU

D.I.C

RFU

D.I.C

DLL

Mode Register

256M GDDR SDRAM

K4D553238F-GC

- 10 -

Rev 1.3 (Mar. 2005)

Permanent device damage may occur if ABSOLUTE MAXIMUM RATINGS 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.

Note :

ABSOLUTE MAXIMUM RATINGS

Parameter

Symbol

Value

Unit

Voltage on any pin relative to Vss

, V

OUT

-0.5 ~ 3.6

Voltage on V

supply relative to Vss

-1.0 ~ 3.6

Voltage on V

supply relative to Vss

DDQ

-0.5 ~ 3.6

Storage temperature

STG

-55 ~ +150

Power dissipation

3.3

Short circuit current

POWER & DC OPERATING CONDITIONS(SSTL_2 In/Out)

Recommended operating conditions(Voltage referenced to V

=0V, T

=0 to 65

Parameter

Symbol

Min

Typ

Max

Unit

Note

Device Supply voltage

2.375

2.5

2.625

Output Supply voltage

DDQ

2.375

2.5

2.625

Reference voltage

REF

0.49*V

DDQ

0.51*V

DDQ

Termination voltage

Vtt

REF

-0.04

REF

+0.04

Input logic high voltage

IH(DC)

REF

+0.15

DDQ

+0.30

Input logic low voltage

IL(DC)

-0.30

REF

-0.15

Output logic high voltage

Vtt+0.76

=-15.2mA, 7

Output logic low voltage

Vtt-0.76

=+15.2mA, 7

Input leakage current

-5

Output leakage current

-5

1. Under all conditions VDDQ must be less than or equal to VDD.
2. VREF is expected to equal 0.50*VDDQ of the transmitting device and to track variations in the DC level of the same. Peak to
peak noise on the VREF may not exceed + 2% of the DC value.
3. Vtt of the transmitting device must track VREF of the receiving device.
4. VIH(max.)= VDDQ +1.5V for a pulse width and it can not be greater than 1/3 of the cycle rate.
5. VIL(mim.)= -1.5V for a pulse width and it can not be greater than 1/3 of the cycle rate.
6. For any pin under test input of 0V < VIN < VDD is acceptable. For all other pins that are not under test VIN=0V.
7. Output logic high voltage and low voltage is depend on output channel condition.

Note :

256M GDDR SDRAM

K4D553238F-GC

- 11 -

Rev 1.3 (Mar. 2005)

DC CHARACTERISTICS

Note : 1. Measured with outputs open.

2. Refresh period is 32ms.

Parameter

Symbol

Test Condition

Version

Unit Note

-2A

-33

-36

Operating Current
(One Bank Active)

CC1

Burst Lenth=2

(min)

=0mA,

(min)

340

310

290

Precharge Standby Current
in Power-down mode

CC2

CKE

(max),

(min)

Precharge Standby Current
in Non Power-down mode

CC2

CKE

(min), CS

(min),

(min)

Active Standby Current
power-down mode

CC3

CKE

(max),

(min)

Active Standby Current
in Non Power-down mode

CC3

CKE

VIH(min), CS

VIH(min),

(min)

240

220

210

Operating Current
( Burst Mode)

CC4

=0mA ,

(min),

Page Burst, All Banks activated.

400

370

360

Refresh Current

CC5

RFC

(min)

380

340

320

Self Refresh Current

CC6

CKE

0.2V

Operating Current
(4Bank interleaving)

CC7

Burst Length=4

(min)

=0mA,

(min)

620

560

530

Recommended operating conditions Unless Otherwise Noted, T

=0 to 65

1. V

is the magnitude of the difference between the input level on CK and the input level on CK

2. The value of V

is expected to equal 0.5*V

DDQ

of the transmitting device and must track variations in the DC level of the same

Note :

AC INPUT OPERATING CONDITIONS

Recommended operating conditions(Voltage referenced to V

=0V, T

=0 to 65

Parameter

Symbol

Min

Typ

Max

Unit

Note

Input High (Logic 1) Voltage ;DQ

REF

+0.35

Input Low (Logic 0) Voltage; DQ

REF

-0.35

Clock Input Differential Voltage; CK and CK

0.7

DDQ

+0.6

Clock Input Crossing Point Voltage; CK and CK

0.5*V

DDQ

-0.2

0.5*V

DDQ

+0.2

256M GDDR SDRAM

K4D553238F-GC

- 12 -

Rev 1.3 (Mar. 2005)

=50

Output

LOAD

=30pF

(Fig. 1) Output Load Circuit

Z0=50

REF

=0.5*V

DDQ

=0.5*V

DDQ

DECOUPLING CAPACITANCE GUIDE LINE

Recommended decoupling capacitance added to power line at board.

Parameter

Symbol

Value

Unit

Decoupling Capacitance between V

and V

DC1

0.1 + 0.01

Decoupling Capacitance between V

DDQ

and V

SSQ

DC2

0.1 + 0.01

1. V

and V

DDQ

pins are separated each other.

All V

pins are connected in chip. All V

DDQ

pins are connected in chip.

2. V

and V

SSQ

pins are separated each other

All V

pins are connected in chip. All V

SSQ

pins are connected in chip.

Note :

AC OPERATING TEST CONDITIONS

= 0 to 65

Note 1 : In case of differential clocks(CK and CK ), input reference voltage for clock is a CK and CK's crossing point.

Parameter

Value

Unit

Note

Input reference voltage for CK(for single ended)

0.50*V

DDQ

CK and CK signal maximum peak swing

1.5

CK signal minimum slew rate

1.0

V/ns

Input Levels(V

)

REF

+0.4/V

REF

-0.4

Input timing measurement reference level

REF

Output timing measurement reference level

Output load condition

See Fig.1

CAPACITANCE

= 25

f=1MHz)

Parameter

Symbol

Min

Max

Unit

Input capacitance(

CK, CK )

IN1

1.0

5.0

Input capacitance(A

, BA

~BA

)

IN2

1.0

4.0

Input capacitance
(

CKE, CS, RAS,CAS, WE )

IN3

1.0

4.0

Data & DQS input/output capacitance(DQ

~DQ

)

OUT

1.0

6.5

Input capacitance(DM0 ~ DM3)

IN4

1.0

6.5

256M GDDR SDRAM

K4D553238F-GC

- 13 -

Rev 1.3 (Mar. 2005)

tCL

tCK

CK, CK

DQS

tIS

tIH

tDS tDH

tRPST

tRPRE

Db0

Db1

tDQSS

tDQSH

tDQSL

tCH

Qa1

Qa2

COMMAND

READA

WRITEB

tDQSQ

WPRES

WPREH

tDQSCK

tAC

Simplified Timing @ BL=2, CL=4

AC CHARACTERISTICS

*1.

The cycle to cycle jitter over 1~6 cycle short term jitter.

Parameter

Symbol

-2A

-33

-36

Unit

Note

Min

Max

Min

Max

Min

Max

CK cycle time

CL=3

tCK

CL=4

2.86

3.3

3.6

CK high level width

tCH

0.45

0.55

0.45

0.55

0.45

0.55

tCK

CK low level width

tCL

0.45

0.55

0.45

0.55

0.45

0.55

tCK

DQS out access time from CK

tDQSCK

-0.55

0.55

-0.55

0.55

-0.6

0.6

Output access time from CK

tAC

-0.55

0.55

-0.55

0.55

-0.6

0.6

Data strobe edge to Dout edge

tDQSQ

0.35

0.40

Read preamble

tRPRE

0.9

1.1

0.9

1.1

0.9

1.1

tCK

Read postamble

tRPST

0.4

0.6

0.4

0.6

0.4

0.6

tCK

CK to valid DQS-in

tDQSS

0.85

1.15

0.85

1.15

0.85

1.15

tCK

DQS-In setup time

tWPRES

DQS-in hold time

tWPREH

0.35

tCK

DQS write postamble

tWPST

0.4

0.6

0.4

0.6

0.4

0.6

tCK

DQS-In high level width

tDQSH

0.45

0.55

0.45

0.55

0.45

0.55

tCK

DQS-In low level width

tDQSL

0.45

0.55

0.45

0.55

0.45

0.55

tCK

Address and Control input setup

tIS

0.8

0.9

Address and Control input hold

tIH

0.8

0.9

DQ and DM setup time to DQS

tDS

0.35

0.40

DQ and DM hold time to DQS

tDH

0.35

0.40

Clock half period

tHP

tCLmin

tCHmin

tCLmin

tCHmin

tCLmin

tCHmin

Data Hold skew factor

tQHS

0.4

0.45

Data output hold time from DQS

tQH

tHP-tQHS

Jitter over 1~6 clock cycle error

tJ*1

Cycle to cyde duty cycle error

tDCERR

Rise and fall times of CK

tR, tF

600

700

256M GDDR SDRAM

K4D553238F-GC

- 14 -

Rev 1.3 (Mar. 2005)

Note 1 :
- The JEDEC DDR specification currently defines the output data valid window(tDV) as the time period when the data
strobe and all data associated with that data strobe are coincidentally valid.
- The previously used definition of tDV(=0.35tCK) artificially penalizes system timing budgets by assuming the worst case
output vaild window even then the clock duty cycle applied to the device is better than 45/55%
- A new AC timing term, tQH which stands for data output hold time from DQS is difined to account for clock duty cycle
variation and replaces tDV
- tQHmin = tHP-X where
. tHP=Minimum half clock period for any given cycle and is defined by clock high or clock low time(tCH,tCL)
. X=A frequency dependent timing allowance account for tDQSQmax

tQH Timing (CL4, BL2)

tHP

CK, CK

DQS

COMMAND

READA

tQH

Qa0

tDQSQ(max)

Qa1

VALID

NOP

VALID

CK, CK

CKE

Command

Exit Powr Down mode

Enter Power Down mode
(Read or Write operation
must not be in progress)

Power Down Timing

256M GDDR SDRAM

K4D553238F-GC

- 15 -

Rev 1.3 (Mar. 2005)

AC CHARACTERISTICS (I)

Note : 1. For normal write operation, even numbers of Din are to be written inside DRAM
2. The number of clock of tRP is restricted by the number of clock of tRAS and tRP
3. The number of clock of tWR_A is fixed. It can't be changed by tCK
4. tRCDWR is equal to tRCDRD-2tCK and the number of clock can not be lower than 2tCK.
5. 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 unconditionally.

Parameter

Symbol

-2A

-33

-36

Unit

Note

Min

Max

Min

Max

Min

Max

Row cycle time

tRC

42.9

46.8

2,5

Refresh row cycle time

tRFC

48.6

49.5

Row active time

tRAS

28.6

100K

29.7

100K

32.4

100K

RAS to CAS delay for Read

tRCDRD

13.2

14.4

RAS to CAS delay for Write

tRCDWR

6.6

7.2

Row precharge time

tRP

13.2

14.4

Row active to Row active

tRRD

9.9

10.8

Last data in to Row precharge

tWR

14.3

16.5

Last data in to Row precharge
@Auto Precharge

tWR_A

tCK

Auto precharge write recovery +
Precharge

tDAL

tCK

3,5

Last data in to Read command

tCDLR

tCK

Col. address to Col. address

tCCD

tCK

Mode register set cycle time

tMRD

tCK

Exit self refresh to read command

tXSR

200

tCK

Power down exit time

tPDEX

3tCK+

tIS

3tCK+

tIS

3tCK+

tIS

Refresh interval time

tREF

7.8

AC CHARACTERISTICS (II)

K4D553238F-GC2A

Frequency

Cas Latency

tRC

tRFC

tRAS

tRCDRD tRCDWR

tRP

tRRD

tDAL

Unit

350MHz ( 2.86ns )

tCK

300MHz ( 3.3ns )

tCK

275MHz ( 3.6ns )

tCK

K4D553238F-GC33

Frequency

Cas Latency

tRC

tRFC

tRAS

tRCDRD tRCDWR

tRP

tRRD

tDAL

Unit

300MHz ( 3.3ns )

tCK

275MHz ( 3.6ns )

tCK

K4D553238F-GC36

Frequency

Cas Latency

tRC

tRFC

tRAS

tRCDRD tRCDWR

tRP

tRRD

tDAL

Unit

275MHz ( 3.6ns )

tCK

256M GDDR SDRAM

K4D553238F-GC

- 16 -

Rev 1.3 (Mar. 2005)

BAa

tRCD

ACTIVEA

ACTIVEB WRITEA

WRITEB

BAa

BAb

BAa

PRECH

BAa

Normal Write Burst

(@ BL=4)

Multi Bank Interleaving Write Burst

(@ BL=4)

BAa

BAb

tRAS

tRC

tRP

tRRD

COMMAND

DQS

CK, CK

A8/AP

ADDR

(A0~A7,

BA[1:0]

A9,A10)

ACTIVEA

WRITEA

Da0 Da1 Da2 Da3

Simplified Timing(2) @ BL=4

Db0 Db1

Db3

Da0 Da1 Da2 Da3

Db2

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ÐÐ»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: K4D553238F-GC