MT46V16M16TG-75ELIT:C - Micron Technology, Inc.

Products and specifications discussed herein are subject to change by Micron without notice.

256Mb: x4, x8, x16 DDR SDRAM

Features

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

Double Data Rate (DDR) SDRAM

MT46V64M4 – 16 Meg x 4 x 4 banks

MT46V32M8 – 8 Meg x 8 x 4 banks

MT46V16M16 – 4 Meg x 16 x 4 banks

For the most current data sheet, please refer to the Micron® Web site: www.micron.com/datasheets

Features

•VDD = +2.5V ±0.2V, VDDQ = +2.5V ±0.2V

•V

DD = +2.6V ±0.1V, VDDQ = +2.6V ±0.1V (DDR400)

• Bidirectional data strobe (DQS) transmitted/

received with data, i.e., source-synchronous data

capture (x16 has two – one per byte)

• Internal, pipelined double-data-rate (DDR)

architecture; two data accesses per clock cycle

• Differential clock inputs (CK and CK#)

• Commands entered on each positive CK edge

• DQS edge-aligned with data for READs; center-

aligned with data for WRITEs

• DLL to align DQ and DQS transitions with CK

• Four internal banks for concurrent operation

• Data mask (DM) for masking write data (x16 has two

– one per byte)

• Programmable burst lengths: 2, 4, or 8

• Auto Refresh and Self Refresh Modes

• Longer-lead TSOP for improved reliability (OCPL)

• 2.5V I/O (SSTL_2 compatible)

• Concurrent auto precharge option supported

•tRAS lockout supported (tRAP = tRCD)

Options Marking

• Configuration

64 Meg x 4 (16 Meg x 4 x 4 banks) 64M4

32 Meg x 8 (8 Meg x 8 x 4 banks) 32M8

16 Meg x 16 (4 Meg x 16 x 4 banks) 16M16

•Plastic Package – OCPL

66-pin TSOP TG

66-pin TSOP (lead-free) P

•Plastic Package

60-Ball FBGA (8mm x 14mm) FG

60-Ball FBGA (8mm x 14mm) lead-free BG

• Timing – Cycle Time

5ns @ CL = 3 (DDR400B) -5B

6ns @ CL = 2.5 (DDR333) FBGA only -6

6ns @ CL = 2.5 (DDR333) TSOP only -6T

7.5ns @ CL = 2 (DDR266) -75E

7.5ns @ CL = 2 (DDR266A) -75Z

7.5ns @ CL = 2.5 (DDR266B) -75

• Self Refresh

Standard None

Low-Power Self Refresh L

•Temperature Rating

Commercial (0°C to +70°C) None

Industrial (-40°C to +85°C) IT

• Revision

x4, x8 :G, :C

x16 :C, :F

Table 1: Configuration Addressing

64 Meg x 4 32 Meg x 8

16 Meg x 16

Configuration 16 Meg x 4 x 4 banks 8 Meg x 8 x 4 banks 4 Meg x 16 x 4 banks

Refresh Count 8K 8K 8K

Row Addressing 8K (A0–A12) 8K (A0–A12) 8K (A0–A12)

Bank Addressing 4 (BA0,BA1) 4 (BA0,BA1) 4 (BA0,BA1)

Column Addressing 2K (A0–A9,A11) 1K (A0–A9) 512 (A0–A8)

Table 2: Key Timing Parameters

CL = CAS (READ) Latency; minimum clock rate @ CL = 2 (-75E, -75Z), CL = 2.5 (-6, -6T, -75), and CL = 3 (-5B)

Speed Grade

Clock Rate

Data- Out

Window

Access

Window

DQS–DQ Skew

CL = 2 CL = 2.5 CL = 3

-5B 133 MHz 167 MHz 200 MHz 1.6ns ±0.70ns +0.40ns

-6 133 MHz 167 MHz N/A 2.1ns ±0.70ns +0.40ns

6T 133 MHz 167 MHz N/A 2.0ns ±0.70ns +0.45ns

-75E/-75Z 133 MHz 133 MHz N/A 2.5ns ±0.75ns +0.50ns

-75 100 MHz 133 MHz N/A 2.5ns ±0.75ns +0.50ns

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

FBGA Part Marking System

Figure 1: 256Mb DDR SDRAM Part Numbers

FBGA Part Marking System

Due to space limitations, FBGA-packaged components have an abbreviated part mark-

ing that is different from the part number. For a quick convertion of an FBGA code, see

the FBGA Part Marking Decoder on the Micron web site, www.micron.com/decoder.

Table 3: Speed Grade Compatibility

Marking PC3200 (3-3-3)

PC2700 (2.5-3-3)

PC2100 (2-2-2) PC2100 (2-3-3)

PC2100 (2.5-3-3)

PC1600 (2-2-2)

-5B Yes Yes Yes Yes Yes Yes

-6 Yes Yes Yes Yes Yes

-6T Yes Yes Yes Yes Yes

-75E Yes Yes Yes Yes

-75Z Yes Yes Yes

-75 Yes Yes

-5B -6/-6T -75E -75Z -75 -75

Special Options

Standard

Low Power

Configuration

64 Meg x 4

32 Meg x 8

16 Meg x 16

64M4

32M8

16M16

Package

400-mil TSOP

400-mil TSOP (lead-free)

8x14 FBGA

8x14 FBGA (lead-free)

BG Speed Grade

tCK = 5ns, CL = 3

tCK = 6ns, CL = 2.5

tCK = 7.5ns, CL = 2

tCK = 7.5ns, CL = 2.5

-5B

-6

-6T

-75E

-75Z

-75

Operating Temp

Standard

Industrial Temp

Revision

x4, x8; x16

x16

x4, x8

Example Part Number: MT46V16M16TG-75E

ConfigurationMT46V Package Speed

Revision

Sp.

Op. Temp.

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

General Description

The 256Mb DDR SDRAM is a high-speed CMOS, dynamic random-access memory con-

taining 268,435,456 bits. It is internally configured as a quad-bank DRAM.

The 256Mb DDR SDRAM uses a double-data-rate architecture to achieve high-speed

operation. The double data rate architecture is essentially a 2n-prefetch architecture

with an interface designed to transfer two data words per clock cycle at the I/O pins. A

single read or write access for the 256Mb DDR SDRAM effectively consists of a single 2n-

bit wide, one-clock-cycle data transfer at the internal DRAM core and two correspond-

ing n-bit wide, one-half-clock-cycle data transfers at the I/O pins.

A bidirectional data strobe (DQS) is transmitted externally, along with data, for use in

data capture at the receiver. DQS is a strobe transmitted by the DDR SDRAM during

READs and by the memory controller during WRITEs. DQS is edge-aligned with data for

READs and center-aligned with data for WRITEs. The x16 offering has two data strobes,

one for the lower byte and one for the upper byte.

The 256Mb DDR SDRAM operates from a differential clock (CK and CK#); the crossing of

CK going HIGH and CK# going LOW will be referred to as the positive edge of CK. Com-

mands (address and control signals) are registered at every positive edge of CK. Input

data is registered on both edges of DQS, and output data is referenced to both edges of

DQS, as well as to both edges of CK.

Read and write accesses to the DDR SDRAM are burst oriented; accesses start at a

selected location and continue for a programmed number of locations in a programmed

sequence. Accesses begin with the registration of an ACTIVE command, which is then

followed by a READ or WRITE command. The address bits registered coincident with the

ACTIVE command are used to select the bank and row to be accessed. The address bits

registered coincident with the READ or WRITE command are used to select the bank and

the starting column location for the burst access.

The DDR SDRAM provides for programmable READ or WRITE burst lengths of 2, 4, or 8

locations. An auto precharge function may be enabled to provide a self-timed row pre-

charge that is initiated at the end of the burst access.

As with standard SDR SDRAMs, the pipelined, multibank architecture of DDR SDRAMs

allows for concurrent operation, thereby effectively providing high bandwidth by hiding

row precharge and activation time.

An auto refresh mode is provided, along with a power-saving power-down mode. All

inputs are compatible with the JEDEC Standard for SSTL_2. All full drive option outputs

are SSTL_2, Class II compatible.

Notes: 1. The functionality and the timing specifications discussed in this data sheet are for the

DLL-enabled mode of operation.

2. Throughout the data sheet, the various figures and text refer to DQs as “DQ.” The DQ

term is to be interpreted as any and all DQ collectively, unless specifically stated oth-

erwise. Additionally, the x16 is divided into two bytes, the lower byte and upper byte.

For the lower byte (DQ0 through DQ7) DM refers to LDM and DQS refers to LDQS. For

the upper byte (DQ8 through DQ15) DM refers to UDM and DQS refers to UDQS.

3. Complete functionality is described throughout the document and any page or dia-

gram may have been simplified to convey a topic and may not be inclusive of all

requirements.

4. Any specific requirement takes precedence over a general statement.

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Table of Contents

Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

FBGA Part Marking System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Pin/Ball Assignments and Descriptions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

Mode Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

Burst Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

Burst Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

Read Latency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Operating Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Extended Mode Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Output Drive Strength. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

DLL Enable/Disable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

DESELECT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

NO OPERATION (NOP). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

LOAD MODE REGISTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

ACTIVE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

READ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

WRITE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

PRECHARGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

Auto Precharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

BURST TERMINATE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

AUTO REFRESH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

SELF REFRESH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24

Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

Bank/Row Activation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

READs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

WRITEs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36

PRECHARGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47

Power-Down (CKE Not Active) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47

Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53

Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69

Output Drive Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75

Data Output Timing Diagrams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77

Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .81

Timing Diagrams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .83

Package Drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .92

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

List of Figures

Figure 1: 256Mb DDR SDRAM Part Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

Figure 2: Functional Block Diagram: 64 Meg x 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Figure 3: Functional Block Diagram: 32 Meg x 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

Figure 4: Functional Block Diagram: 16 Meg x 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

Figure 5: Pin Assignment (Top View) 66-Pin TSOP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

Figure 6: 60-Ball FBGA Ball Assignment (Top View) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

Figure 7: Mode Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

Figure 8: CAS Latency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18

Figure 9: Extended Mode Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Figure 10: Activating a Specific Row in a Specific Bank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

Figure 11: Example: Meeting tRCD (tRRD) MIN When 2 < tRCD (tRRD) MIN/tCK ≤ 3 . . . . . . . . . . . . . . . . . . . . . .26

Figure 12: READ Command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28

Figure 13: READ Burst. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

Figure 14: Consecutive READ Bursts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30

Figure 15: Nonconsecutive READ Bursts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

Figure 16: Random READ Accesses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

Figure 17: Terminating a READ Burst . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

Figure 18: READ to WRITE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

Figure 19: READ to PRECHARGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35

Figure 20: WRITE Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

Figure 21: WRITE Burst. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

Figure 22: Consecutive WRITE to WRITE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

Figure 24: Random WRITE Cycles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40

Figure 25: WRITE to READ - Uninterrupting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41

Figure 26: WRITE to READ – Interrupting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42

Figure 27: WRITE to READ – Odd Number of Data, Interrupting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43

Figure 28: WRITE to PRECHARGE - Uninterrupting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44

Figure 29: WRITE to PRECHARGE – Interrupting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45

Figure 30: WRITE to PRECHARGE – Odd Number of Data – Interrupting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46

Figure 31: PRECHARGE Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47

Figure 32: Power-Down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48

Figure 33: Input Voltage Waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55

Figure 34: SSTL_2 Clock Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56

Figure 35: Derating Data Valid Window (tQH - tDQSQ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71

Figure 36: Full Drive Pull-Down Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72

Figure 37: Full Drive Pull-Up Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72

Figure 38: Reduced Drive Pull-Down Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73

Figure 39: Reduced Drive Pull-Up Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73

Figure 40: x4, x8 Data Output Timing – tDQSQ, tQH, and Data Valid Window . . . . . . . . . . . . . . . . . . . . . . . . . . . .77

Figure 41: x16 Data Output Timing – tDQSQ, tQH, and Data Valid Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .78

Figure 42: Data Output Timing – tAC and tDQSCK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .79

Figure 43: Data Input Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .80

Figure 44: Initialization Flow Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .82

Figure 45: Initialize and Load Mode Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .83

Figure 46: Power-Down Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84

Figure 47: Auto Refresh Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85

Figure 48: Self Refresh Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86

Figure 49: Bank Read - Without Auto Precharge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .87

Figure 50: Bank Read - With Auto Precharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .88

Figure 51: Bank Write - Without Auto Precharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .89

Figure 52: Bank Write - With Auto Precharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .90

Figure 53: Write – DM Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .91

Figure 54: 66-Pin Plastic TSOP (400 mil). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .92

Figure 55: 60-Ball FBGA (8x14mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .93

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

List of Tables

Table 1: Configuration Addressing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

Table 2: Key Timing Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

Table 3: Speed Grade Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

Table 4: Ball/Pin Descriptions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Table 5: Reserved NC Balls and Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

Table 6: Burst Definition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Table 7: CAS Latency (CL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18

Table 8: Truth Table – Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

Table 9: Truth Table – DM Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

Table 10: Truth Table – CKE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48

Table 11: Truth Table – Current State Bank n – Command to Bank n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49

Table 12: Truth Table – Current State Bank n– Command to Bank m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51

Table 13: Minimum Delay Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52

Table 14: DC Electrical Characteristics and Operating Conditions (-6, -6T, -75E, -75Z, -75) . . . . . . . . . . . . . . .53

Table 15: DC Electrical Characteristics and Operating Conditions (-5B DDR400) . . . . . . . . . . . . . . . . . . . . . . . .54

Table 16: AC Input Operating Conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55

Table 17: Clock Input Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56

Table 18: Capacitance (x4, x8 TSOP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57

Table 19: Capacitance (x16 TSOP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57

Table 20: IDD Specifications and Conditions (x4, x8; -5B) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58

Table 21: IDD Specifications and Conditions (x4, x8; -6/-6T/-75E) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59

Table 22: IDD Specifications and Conditions (x4, x8; -75Z/-75) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60

Table 23: IDD Specifications and Conditions (x16; -5B) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61

Table 24: IDD Specifications and Conditions (x16; -6/-6T/-75E) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62

Table 25: IDD Specifications and Conditions (x16; -75Z/-75) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63

Table 26: IDD Test Cycle Times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64

Table 27: Electrical Characteristics and Recommended AC Operating Conditions (-5B) . . . . . . . . . . . . . . . . . .65

Table 28: Electrical Characteristics and Recommended AC Operating Conditions (-6/-6T/-75E) . . . . . . . . . .66

Table 29: Electrical Characteristics and Recommended AC Operating Conditions (-75Z/-75) . . . . . . . . . . . . .67

Table 30: Input Slew Rate Derating Values for Addresses and Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68

Table 31: Input Slew Rate Derating Values for DQ, DQS, and DM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68

Table 32: Normal Output Drive Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75

Table 33: Reduced Output Drive Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Figure 2: Functional Block Diagram: 64 Meg x 4

RAS#

CAS#

ROW-

ADDRESS

MUX

CS#

WE#

CK#

CONTROL

LOGIC

COLUMN-

ADDRESS

COUNTER/

LATCH

MODE REGISTERS

COMMAND

DECODE

A0-A12,

BA0, BA1

CKE

ADDRESS

1024

(x8)

8192

I/O GATING

DM MASK LOGIC

COLUMN

DECODER

BANK0

MEMORY

ARRAY

(8,192 x 1,024 x 8)

BANK0

ROW-

ADDRESS

LATCH

DECODER

8192

SENSE AMPLIFIERS

BANK

CONTROL

LOGIC

BANK1

BANK2

BANK3

REFRESH

COUNTER

INPUT

REGISTERS

RCVRS

clk

out

DATA

DQS

MASK

DATA

COL0

clk

DRVRS

DLL

MUX

DQS

GENERATOR

DQ0–

DQ3

DQS

READ

LATCH

WRITE

FIFO

DRIVERS

COL0

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Figure 3: Functional Block Diagram: 32 Meg x 8

RAS#

CAS#

ROW-

ADDRESS

MUX

CS#

WE#

CK#

CONTROL

LOGIC

COLUMN-

ADDRESS

COUNTER/

LATCH

MODE REGISTERS

COMMAND

DECODE

A0-A12,

BA0, BA1

CKE

ADDRESS

512

(x16)

8192

I/O GATING

DM MASK LOGIC

COLUMN

DECODER

BANK0

MEMORY

ARRAY

(8192 x 512 x 16)

BANK0

ROW-

ADDRESS

LATCH

DECODER

8192

SENSE AMPLIFIERS

BANK

CONTROL

LOGIC

BANK1

BANK2

BANK3

REFRESH

COUNTER

INPUT

REGISTERS

RCVRS

clk

out

DATA

DQS

MASK

DATA

clk

DRVRS

DLL

MUX

DQS

GENERATOR

DQ0–

DQ7

DQS

READ

LATCH

WRITE

FIFO

DRIVERS

COL0

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Figure 4: Functional Block Diagram: 16 Meg x 16

RAS#

CAS#

ROW-

ADDRESS

MUX

CS#

WE#

CK#

CONTROL

LOGIC

COLUMN-

ADDRESS

COUNTER/

LATCH

MODE REGISTERS

COMMAND

DECODE

A0-A12,

BA0, BA1

CKE

ADDRESS

256

(x32)

8192

I/O GATING

DM MASK LOGIC

COLUMN

DECODER

BANK0

MEMORY

ARRAY

(8,192 x 256 x 32)

BANK0

ROW-

ADDRESS

LATCH

DECODER

8192

SENSE AMPLIFIERS

BANK

CONTROL

LOGIC

BANK1

BANK2

BANK3

REFRESH

COUNTER

INPUT

REGISTERS

RCVRS

clk

out

DATA

DQS

MASK

DATA

clk

DRVRS

DLL

MUX

DQS

GENERATOR

DQ0 -

DQ15

LDQS

UDQS

READ

LATCH

WRITE

FIFO

DRIVERS

COL0

LDM,

UDM

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Pin/Ball Assignments and Descriptions

Table 4: Ball/Pin Descriptions

FBGA

Numbers

TSOP

Numbers Symbol Type Description

G2, G3 45, 46 CK, CK# Input Clock: CK and CK# are differential clock inputs. All address and

control input signals are sampled on the crossing of the positive

edge of CK and the negative edge of CK#. Output data (DQ and

DQS) is referenced to the crossings of CK and CK#.

H3 44 CKE Input Clock Enable: CKE HIGH activates and CKE LOW deactivates the

internal clock, input buffers, and output drivers. Taking CKE LOW

provides PRECHARGE POWER-DOWN and SELF REFRESH operations

(all banks idle) or ACTIVE POWER-DOWN (row ACTIVE in any bank).

CKE is synchronous for POWER-DOWN entry and exit and for SELF

REFRESH entry. CKE is asynchronous for SELF REFRESH exit and for

disabling the outputs. CKE must be maintained HIGH throughout

read and write accesses. Input buffers (excluding CK, CK#, and CKE)

are disabled during POWER- DOWN. Input buffers (excluding CKE)

are disabled during SELF REFRESH. CKE is an SSTL_2 input but will

detect an LVCMOS LOW level after VDD is applied and until CKE is

first brought HIGH, after which it becomes a SSTL_2 input only.

H8 24 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.

H7, G8, G7 23, 22, 21 RAS#, CAS#,

WE#

Input Command Inputs: RAS#, CAS#, and WE# (along with CS#) define

the command being entered.

3F 47 DM Input Input Data Mask: DM is an input mask signal for write data. Input

data is masked when DM is sampled HIGH along with that input

data during a WRITE access. DM is sampled on both edges of DQS.

Although DM pins are input-only, the DM loading is designed to

match that of DQ and DQS pins. For the x16, LDM is DM for DQ0–

DQ7 and UDM is DM for DQ8–DQ15. Pin 20 is a NC on x4 and x8.

F7, 3F 20, 47 LDM, UDM

J8, J7 26, 27 BA0, BA1 Input Bank Address Inputs: BA0 and BA1 define to which bank an

ACTIVE, READ, WRITE, or PRECHARGE command is being applied.

K7, L8, L7,

M8, M2, L3,

L2, K3, K2,

J3, K8,

J2, H2

29, 30, 31,

32, 35, 36,

37, 38, 39,

40, 28

41, 42

A0, A1, A2,

A3, A4, A5,

A6, A7, A8,

A9, A10,

A11, A12

Input Address Inputs: Provide the row address for ACTIVE commands, and

the column address and auto precharge bit (A10) for READ/WRITE

commands, to select one location out of the memory array in the

respective bank. A10 sampled during a PRECHARGE command

determines whether the PRECHARGE applies to one bank (A10

LOW, bank selected by BA0, BA1) or all banks (A10 HIGH). The

address inputs also provide the op-code during a MODE REGISTER

SET command. BA0 and BA1 define which mode register (mode

MODE REGISTER command.

A8, B9, B7,

C9, C7, D9,

D7, E9, E1,

D3, D1, C3,

C1, B3, B1,

2, 4, 5,

7, 8, 10,

11, 13, 54,

56, 57, 59,

60, 62, 63,

DQ0–DQ2

DQ3–DQ5

DQ6–DQ8

DQ9–DQ11

DQ12–DQ14

DQ15

I/O Data Input/Output: Data bus for x16.

14, 17, 25, 43,

NC – No Connect for x16

These pins should be left unconnected.

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Pin/Ball Assignments and Descriptions

A8, B7, C7,

D7, D3, C3,

B3, A2

2, 5, 8,

11, 56, 59,

62, 65

DQ0–DQ2

DQ3–DQ5

DQ6, DQ7

I/O Data Input/Output: Data bus for x8.

B1, B9, C1, C9,

D1, D9, E1,

E7, E9, F7

4, 7, 10, 13,

14, 16, 17, 20,

25, 43, 53, 54,

57, 60, 63,

NC – No Connect for x8

These pins should be left unconnected.

B7, D7, D3,

5, 11, 56,

DQ0–DQ2

DQ3

I/O Data Input/Output: Data bus for x4.

B1, B9, C1, C9,

D1, D9, E1,

E7, E9, F7,

4, 7, 10, 13,

14, 16, 17, 20,

25, 43, 53, 54,

57, 60, 63,

NC – No Connect for x4

These pins should be left unconnected.

A2, A8, C3, C7 2, 8, 59, 65 NF – No Function for x4

These pins should be left unconnected.

DQS

LDQS

UDQS

I/O Data Strobe: Output with read data, input with write data. DQS is

edge-aligned with read data, centered in write data. It is used to

capture data. For the x16, LDQS is DQS for DQ0–DQ7 and UDQS is

DQS for DQ8–DQ15. Pin 16 (E7) is NC on x4 and x8.

F9 17, 19, 50 DNU –Do Not Use: Must float to minimize noise on VREF.

B2, D2, C8,

E8, A9

3, 9, 15,

55, 61

VDDQSupply DQ Power Supply: +2.5V ±0.2V (+2.6V ±0.1V for DDR400). Isolated

on the die for improved noise immunity.

A1, C2, E2,

B8, D8

6, 12, 52,

58, 64

VSSQSupply DQ Ground: Isolated on the die for improved noise immunity.

F8, M7, A7 1, 18, 33 VDD Supply Power Supply: +2.5V ±0.2V (+2.6V ±0.1V for DDR400).

A3, F2, M3 34, 48, 66 VSS Supply Ground.

F1 49 VREF Supply SSTL_2 reference voltage.

Table 5: Reserved NC Balls and Pins

NC pins not listed may also be reserved for other uses; this table defines NC pins of importance

FBGA

NUMBERS

TSOP

NUMBERS SYMBOL TYPE DESCRIPTION

F9 17 A13 I Address input A13 for 1Gb devices. DNU for FBGA.

Table 4: Ball/Pin Descriptions (Continued)

FBGA

Numbers

TSOP

Numbers Symbol Type Description

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Pin/Ball Assignments and Descriptions

Figure 5: Pin Assignment (Top View) 66-Pin TSOP

DQ15

DQ14

DQ13

DQ12

DQ11

DQ10

DQ9

DQ8

UDQS

DNU

REF

UDM

CK#

CKE

A12

A11

x16

DQ0

DQ1

DQ2

VssQ

DQ3

DQ4

DQ5

DQ6

VssQ

DQ7

LDQS

DNU

LDM

WE#

CAS#

RAS#

CS#

BA0

BA1

A10/AP

x16

DQ7

DQ6

DQ5

DQ4

DQS

DNU

REF

CK#

CKE

A12

A11

x8 x4

DQ3

DQ2

DQS

DNU

REF

CK#

CKE

A12

A11

DQ0

DQ1

DQ2

DQ3

DNU

WE#

CAS#

RAS#

CS#

BA0

BA1

A10/AP

x8x4

DQ0

DQ1

DNU

WE#

CAS#

RAS#

CS#

BA0

BA1

A10/AP

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Pin/Ball Assignments and Descriptions

Figure 6: 60-Ball FBGA Ball Assignment (Top View)

DQ14

DQ12

DQ10

DQ8

REF

DQ15

A12

A11

DQ13

DQ11

DQ9

UDQS

UDM

CK#

CKE

DQ2

DQ4

DQ6

LDQS

LDM

WE#

RAS#

BA1

DQ0

CAS#

CS#

BA0

A10

DQ1

DQ3

DQ5

DQ7

DNU

x16 (Top View)

REF

A12

A11

DQ3

DQ2

DQS

CK#

CKE

DQ0

DQ1

WE#

RAS#

BA1

CAS#

CS#

BA0

A10

DNU

x4 (Top View)

REF

DQ7

A12

A11

DQ6

DQ5

DQ4

DQS

CK#

CKE

DQ1

DQ2

DQ3

WE#

RAS#

BA1

DQ0

CAS#

CS#

BA0

A10

DNU

x8 (Top View)

1 2 3456789

12 3456789

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Functional Description

The 256Mb DDR SDRAM is a high-speed CMOS, dynamic random-access memory con-

taining 268,435,456 bits. The 256Mb DDR SDRAM is internally configured as a quad-

bank DRAM.

The 256Mb DDR SDRAM uses a double data rate architecture to achieve high-speed

operation. The double data rate architecture is essentially a 2n-prefetch architecture,

with an interface designed to transfer two data words per clock cycle at the I/O pins. A

single read or write access for the 256Mb DDR SDRAM consists of a single 2n-bit wide,

one-clock-cycle data transfer at the internal DRAM core and two corresponding n-bit

wide, one-half-clock-cycle data transfers at the I/O pins.

Read and write accesses to the DDR SDRAM are burst oriented; accesses start at a

selected location and continue for a programmed number of locations in a programmed

sequence. Accesses begin with the registration of an ACTIVE command, which is then

followed by a READ or WRITE command. The address bits registered coincident with the

ACTIVE command are used to select the bank and row to be accessed (BA0, BA1 select

the bank; A0–A12 select the row). The address bits registered coincident with the READ

or WRITE command are used to select the starting column location for the burst access.

Prior to normal operation, the DDR SDRAM must be initialized. The following sections

provide detailed information covering device initialization, register definition, com-

mand descriptions, and device operation.

Initialization

DDR SDRAMs must be powered up and initialized in a predefined manner. Operational

procedures other than those specified may result in undefined operation. Power must

first be applied to VDD and VDDQ simultaneously, and then to VREF (and to the system

VTT). VTT must be applied after VDDQ to avoid device latch-up, which may cause perma-

nent damage to the device. VREF can be applied any time after VDDQ but is expected to

be nominally coincident with VTT. Except for CKE, inputs are not recognized as valid

until after VREF is applied. CKE is an SSTL_2 input but will detect an LVCMOS LOW level

after VDD is applied. After CKE passes through VIH, it will transition to a SSTL_2 signal

and remain as such until power is cycled. Maintaining an LVCMOS LOW level on CKE

during power-up is required to ensure that the DQ and DQS outputs will be in the High-

Z state, where they will remain until driven in normal operation (by a read access). After

all power supply and reference voltages are stable, and the clock is stable, the DDR

SDRAM requires a 200µs delay prior to applying an executable command.

Once the 200µs delay has been satisfied, a DESELECT or NOP command should be

applied and CKE should be brought HIGH. Following the NOP command, a PRE-

CHARGE ALL command should be applied. Next a LOAD MODE REGISTER command

should be issued for the extended mode register (BA1 LOW and BA0 HIGH) to enable the

DLL, followed by another LOAD MODE REGISTER command to the mode register (BA0/

BA1 both LOW) to reset the DLL and to program the operating parameters. Two hundred

clock cycles are required between the DLL reset and any READ command. A PRE-

CHARGE ALL command should then be applied, placing the device in the all banks idle

state.

Once in the idle state, two AUTO REFRESH cycles must be performed (tRFC must be sat-

isfied). Additionally, a LOAD MODE REGISTER command for the mode register with the

reset DLL bit deactivated (i.e., to program operating parameters without resetting the

DLL) is required. Following these requirements, the DDR SDRAM is ready for normal

operation.

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Mode Register

The mode register is used to define the specific mode of operation of the DDR SDRAM.

This definition includes the selection of a burst length, a burst type, a CAS latency, and

an operating mode, as shown in Figure 7 on page 16. The mode register is programmed

via the MODE REGISTER SET command (with BA0 = 0 and BA1 = 0) and will retain the

stored information until it is programmed again or the device loses power (except for bit

A8, which is self-clearing).

Reprogramming the mode register will not alter the contents of the memory, provided it

is performed correctly. The mode register must be loaded (reloaded) when all banks are

idle and no bursts are in progress, and the controller must wait the specified time before

initiating the subsequent operation. Violating either of these requirements will result in

unspecified operation.

Mode register bits A0–A2 specify the burst length; A3 specifies the type of burst (sequen-

tial or interleaved); A4–A6 specify the CAS latency; and A7–A12 specify the operating

mode.

Burst Length

Read and write accesses to the DDR SDRAM are burst oriented, with the burst length

being programmable, as shown in Figure 7. The burst length determines the maximum

number of column locations that can be accessed for a given READ or WRITE command.

Burst lengths of 2, 4, or 8 locations are available for both the sequential and the inter-

leaved burst types.

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–Ai when the burst length is set to two, by A2–Ai when the burst

length is set to four, and by A3-Ai when the burst length is set to eight (where Ai is the

most significant column address bit for a given configuration). The remaining (least sig-

nificant) address bit(s) is (are) used to select the starting location within the block. The

programmed burst length applies to both READ and WRITE bursts.

Burst Type

Accesses within a given burst may be programmed to be either sequential or interleaved;

this is referred to as the burst type and is selected via bit M3.

The ordering of accesses within a burst is determined by the burst length, the burst type,

and the starting column address, as shown in Table 6, Burst Definition, on page 17.

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Figure 7: Mode Register Definition

Operating Mode

Normal Operation

Normal Operation/Reset DLL

All other states reserved

Valid

Burst Type

Sequential

Interleaved

CAS Latency

Reserved

2.5

Reserved

Burst LengthCAS Latency BT0*

A9 A7 A6 A5 A4 A3A8 A2 A1 A0

Mode Register (Mx)

Address Bus

976543

8210

M6-M0

M8 M7

Operating Mode

A10A12 A11BA0BA1

* M14 and M13 (BA1 and BA0)

must be “0, 0” to select the

base mode register (vs. the

extended mode register).

M9M10M12 M11

Burst Length

Reserved

CAS Latency

Reserved

2.5

Reserved

(DDR400)

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Notes: 1. Whenever a boundary of the block is reached within a given sequence above, the follow-

ing access wraps within the block.

2. For a burst length of two, A1–Ai select the two-data-element block; A0 selects the first

access within the block.

3. For a burst length of four, A2–Ai select the four-data-element block; A0–A1 select the first

access within the block.

4. For a burst length of eight, A3–Ai select the eight-data-element block; A0–A2 select the

first access within the block.

Read Latency

The READ latency is the delay, in clock cycles, between the registration of a READ com-

mand and the availability of the first bit of output data. The latency can be set to 2, 2.5 or

3 (DDR400 only) clocks, as shown in Figure 8.

If a READ command is registered at clock edge n, and the latency is m clocks, the data

will be available nominally coincident with clock edge n + m. Table 7, CAS Latency (CL),

on page 18 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.

Table 6: Burst Definition

Burst Length

Starting Column

Address

Order of Accesses Within a Burst

Type = Sequential Type = Interleaved

2A0

00-1 0-1

11-0 1-0

4A1A0

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

8A2A1A0

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

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Figure 8: CAS Latency

Table 7: CAS Latency (CL)

Speed

Allowable Operating Clock Frequency (MHz)

CL = 2 CL = 2.5 CL = 3

-5B 75 ≤ f ≤ 133 75 ≤ f ≤ 167 133 ≤ f ≤ 200

-6/-6T 75 ≤ f ≤ 133 75 ≤ f ≤ 167 –

-75E 75 ≤ f ≤ 133 75 ≤ f ≤ 133 –

-75Z 75 ≤ f ≤ 133 75 ≤ f ≤ 133 –

-75 75 ≤ f ≤ 100 75 ≤ f ≤ 133 –

CK#

COMMAND

DQS

CL = 2

READ NOP NOP NOP

Burst Length = 4 in the cases shown

Shown with nominal tAC, tDQSCK, and tDQSQ

CK#

COMMAND

DQS

CL = 2.5

T0 T1 T2 T2n T3 T3n

DON’T CARETRANSITIONING DATA

READ NOP NOP NOP

CK#

COMMAND

DQS

CL = 3

T0 T1 T2 T3 T3n

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Extended Mode Register

Operating Mode

The normal operating mode is selected by issuing a MODE REGISTER SET command

with bits A7–A12 each set to zero, and bits A0–A6 set to the desired values. A DLL reset is

initiated by issuing a MODE REGISTER SET command with bits A7 and A9–A12 each set

to zero, bit A8 set to one, and bits A0–A6 set to the desired values. Although not required

by the Micron device, JEDEC specifications recommend when a LOAD MODE REGISTER

command is issued to reset the DLL, it should always be followed by a LOAD MODE

All other combinations of values for A7–A12 are reserved for future use and/or test

modes. Test modes and reserved states should not be used, as unknown operation or

incompatibility with future versions may result.

Extended Mode Register

The extended mode register controls functions beyond those controlled by the mode

These functions are controlled via the bits shown in Figure 9. The extended mode regis-

ter is programmed via the LOAD MODE REGISTER command to the mode register (with

BA0 = 1 and BA1 = 0) and will retain the stored information until it is programmed again

or the device loses power. The enabling of the DLL should always be followed by a LOAD

MODE REGISTER command to the mode register (BA0/BA1 both LOW ) to reset the DLL.

Anytime a DLL reset occurs, 200 clock cycles with CKE high is required before a READ

command can be issued.

The extended mode register must be loaded when all banks are idle and no bursts are in

progress, and the controller must wait the specified time before initiating any subse-

quent operation. Violating either of these requirements could result in unspecified oper-

ation.

Output Drive Strength

The normal drive strength for all outputs are specified to be SSTL_2, Class II. The x16

supports a programmable option for reduced drive. This option is intended for the sup-

port of the lighter load and/or point-to-point environments. The selection of the

reduced drive strength will alter the DQ pins and DQS pins from SSTL_2, Class II drive

strength to a reduced drive strength, which is approximately 54 percent of the SSTL_2,

Class II drive strength.

DLL Enable/Disable

When the part is running without the DLL enabled, device functionality may be altered.

The DLL must be enabled for normal operation. DLL enable is required during power-

up initialization and upon returning to normal operation after having disabled the DLL

for the purpose of debug or evaluation. (When the device exits self refresh mode, the

DLL is enabled automatically.) Any time the DLL is enabled, a DLL Reset and 200 clock

cycles with CKE high must occur before a READ command can be issued.

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Extended Mode Register

Figure 9: Extended Mode Register Definition

Notes: 1. E14 and E13 (BA1 and BA0) must be “0, 1” to select the extended mode register vs. the

base mode register.

2. The reduced drive strength option is not supported on the x4 and x8 versions; it is only

available on the x16 version.

3. The QFC# option is not supported.

Operating Mode

Reserved

–

Valid

–

DLL

Enable

Disable

DLL

A9 A7 A6 A5 A4 A3A8 A2 A1 A0

Extended Mode

Address Bus

976543

8210

Drive Strength

Normal

Reduced

E1,

Operating Mode

A10A11

A12

BA1 BA0

1314

E3E4

–

E6 E5

E7E8E9

–

E10E11

–

E12

–

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Commands

Table 8 and Table 9 provide a quick reference of available commands, followed by a

description of each command. Two additional truth tables, Table 11 on page 49, and

Table 12 on page 51, appear following the Operation section, provide current state/next

state information.

Notes: 1. CKE is HIGH for all commands shown except SELF REFRESH.

2. BA0–BA1 select either the mode register or the extended mode register (BA0 = 0, BA1 = 0

select the mode register;

BA0 = 1, BA1 = 0 select extended mode register; other combinations of BA0–BA1 are

reserved). A0-A12 provide the op-code to be written to the selected mode register.

3. BA0–BA1 provide bank address and A0–A12 provide row address.

4. BA0–BA1 provide bank address; A0–Ai provide column address, (where i = 8 for x16, i = 9

for x8, and i = 9,11 for x4) A10 HIGH enables the auto precharge feature (non persistent);

and A10 LOW disables the auto precharge feature.

5. A10 LOW: BA0–BA1 determine which bank is precharged.

A10 HIGH: all banks are precharged and BA0–BA1 are “Don’t Care.”

6. This command is AUTO REFRESH if CKE is HIGH, SELF REFRESH if CKE is LOW.

7. Internal refresh counter controls row addressing; within the self refresh mode, all inputs

and I/Os are “Don’t Care” except for CKE.

8. Applies only to READ bursts with auto precharge disabled; this command is undefined

(and should not be used) for READ bursts with auto precharge enabled and for WRITE

bursts.

9. DESELECT and NOP are functionally interchangeable.

Notes: 1. Used to mask write data; provided coincident with the corresponding data.

Table 8: Truth Table – Commands

Note 1 applies to all commands.

Name (Function) CS# RAS# CAS# WE# Addr Notes

DESELECT (NOP) HXXX X 9

NO OPERATION (NOP) LHHH X 9

ACTIVE (Select bank and activate row) L L H H Bank/Row 3

READ (Select bank and column, and start READ burst) LHLHBank/Col4

WRITE (Select bank and column, and start WRITE burst) L H L L Bank/Col 4

BURST TERMINATE LHHL X 8

PRECHARGE (Deactivate row in bank or banks) L L H L Code 5

AUTO REFRESH or SELF REFRESH

(Enter self refresh mode)

LLLH X 6, 7

LOAD MODE REGISTER LLLLOp-Code2

Table 9: Truth Table – DM Operation

Note 1 applies to all commands

Name (Function) DM DQ

Write Enable LValid

Write Inhibit HX

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Commands

DESELECT

The DESELECT function (CS# HIGH) prevents new commands from being executed by

the DDR SDRAM. The DDR SDRAM is effectively deselected. Operations already in

progress are not affected.

NO OPERATION (NOP)

The NO OPERATION (NOP) command is used to instruct the selected DDR SDRAM to

perform a NOP (CS# is LOW with RAS#, CAS#, and WE# are HIGH). This prevents

unwanted commands from being registered during idle or wait states. Operations

already in progress are not affected.

LOAD MODE REGISTER

The mode registers are loaded via inputs A0–A12. See mode register descriptions in the

be issued when all banks are idle, and a subsequent executable command cannot be

issued until tMRD is met.

ACTIVE

The ACTIVE command is used to open (or activate) a row in a particular bank for a sub-

sequent access. The value on the BA0, BA1 inputs selects the bank, and the address pro-

vided on inputs A0–A12 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 opening 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–Ai (where i

= 8 for x16, 9 for x8, or 9, 11 for x4) 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.

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–Ai

(where i = 8 for x16, 9 for x8, or 9, 11 for x4) 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 DQ is written to the memory array subject to the DM input logic

level appearing coincident with the data. If a given DM signal is registered LOW, the cor-

responding data will be written to memory; if the DM signal is registered HIGH, the cor-

responding 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 (tRP) after the PRECHARGE command is issued, except in the case of con-

current auto precharge, where a READ or WRITE command to a different bank is allowed

as long as it does not interrupt the data transfer in the current bank and does not violate

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Commands

any other timing parameters. 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 “Don’t Care.” Once a bank has been

precharged, it is in the idle state and must be activated prior to any READ or WRITE

commands being issued to that bank. A PRECHARGE command will be treated as a NOP

if there is no open row in that bank (idle state) or if the previously open row is already in

the process of precharging.

Auto Precharge

Auto precharge is a feature that performs the same individual-bank precharge function

described above, but without requiring an explicit command. This is accomplished by

using A10 to enable auto precharge in conjunction with a specific READ or WRITE com-

mand. A precharge of the bank/row that is addressed with the READ or WRITE com-

mand is automatically performed upon completion of the READ or WRITE burst. Auto

precharge is non persistent in that it is either enabled or disabled for each individual

READ or WRITE command. This device supports concurrent auto precharge if the com-

mand to the other bank does not interrupt the data transfer to the current bank.

Auto precharge ensures that the precharge is initiated at the earliest valid stage within a

burst. This earliest valid stage is determined as if an explicit PRECHARGE command was

issued at the earliest possible time, without violating tRAS (MIN), as described for each

burst type in the Operation section of this data sheet. The user must not issue another

command to the same bank until the precharge time (tRP) is completed.

BURST TERMINATE

The BURST TERMINATE command is used to truncate READ bursts (with auto pre-

charge disabled). The most recently registered READ command prior to the BURST TER-

MINATE command will be truncated, as shown in the Operation section of this data

sheet. The open page, which the READ burst was terminated from, remains open.

AUTO REFRESH

AUTO REFRESH is used during normal operation of the DDR SDRAM and is analogous

to CAS#-BEFORE-RAS# (CBR) refresh in FPM/EDO DRAMs. This command is nonper-

sistent, so it must be issued each time a refresh is required. All banks must be idle before

an AUTO REFRESH command is issued.

The addressing is generated by the internal refresh controller. This makes the address

bits a “Don’t Care” during an AUTO REFRESH command. The 256Mb DDR SDRAM

requires AUTO REFRESH cycles at an average interval of 7.8125µs (maximum).

To allow for improved efficiency in scheduling and switching between tasks, some flexi-

bility in the absolute refresh interval is provided. A maximum of eight AUTO REFRESH

commands can be posted to any given DDR SDRAM, meaning that the maximum abso-

lute interval between any AUTO REFRESH command and the next AUTO REFRESH

command is 9 x 7.8125µs (70.3µs). Note, the JEDEC specification only allows 8 x

7.8125µs, thus the Micron specification exceeds the JEDEC requirement by one clock.

This maximum absolute interval is to allow future support for DLL updates internal to

the DDR SDRAM to be restricted to AUTO REFRESH cycles, without allowing excessive

drift in tAC between updates.

Although not a JEDEC requirement, to provide for future functionality, CKE must be

active (HIGH) during the auto refresh period. The auto refresh period begins when the

AUTO REFRESH command is registered and ends tRFC later.

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Commands

SELF REFRESH

The SELF REFRESH command can be used to retain data in the DDR SDRAM, even if the

rest of the system is powered down. When in the self refresh mode, the DDR SDRAM

retains data without external clocking. The SELF REFRESH command is initiated like an

AUTO REFRESH command except CKE is disabled (LOW). The DLL is automatically dis-

abled upon entering SELF REFRESH and is automatically enabled upon exiting SELF

REFRESH. (A DLL reset and 200 clock cycles must then occur before a READ command

can be issued.) Input signals except CKE are “Don’t Care” during SELF REFRESH. VREF

voltage is also required for the full duration of the SELF REFRESH.

The procedure for exiting self refresh requires a sequence of commands. First, CK and

CK# must be stable prior to CKE going back HIGH. Once CKE is HIGH, the DDR SDRAM

must have NOP commands issued for tXSNR because time is required for the comple-

tion of any internal refresh in progress. A simple algorithm for meeting both refresh and

DLL requirements is to apply NOPs for tXSNR time, then a DLL reset and NOPs for 200

additional clock cycles before applying any other command.

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

Bank/Row Activation

Before any READ or WRITE commands can be issued to a bank within the DDR 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, as shown in Figure 10.

After a row is opened with an ACTIVE command, a READ or WRITE command may be

issued to that row, subject to the tRCD specification. tRCD (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 tRCD specification of 20ns with a 133 MHz clock (7.5ns period)

results in 2.7 clocks rounded to 3. This is reflected in Figure 11, which covers any case

where 2 < tRCD (MIN)/tCK ≤ 3. (Figure 11 also shows the same case for tRRD; the same

procedure is used to convert other specification limits from time units to clock cycles.)

A subsequent ACTIVE command to a different row in the same bank can only be issued

after the previous active row has been “closed” (precharged). The minimum time inter-

val between successive ACTIVE commands to the same bank is defined by tRC.

A subsequent ACTIVE command to another bank can be issued while the first bank is

being accessed, which results in a reduction of total row-access overhead. The minimum

time interval between successive ACTIVE commands to different banks is defined by

tRRD.

Figure 10: Activating a Specific Row in a Specific Bank

CS#

WE#

CAS#

RAS#

CKE

A0–A12 RA

RA = Row Address

BA = Bank Address

HIGH

BA0, BA1 BA

CK#

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 11: Example: Meeting tRCD (tRRD) MIN When 2 < tRCD (tRRD) MIN/tCK ≤ 3

COMMAND

BA0, BA1

ACT ACT

NOP

RRD t

RCD

CK#

Bank x Bank y

A0–A12

Row Row

NOP RD/WR

NOP

Bank y

Col

NOP

T0 T1 T2 T3 T4 T5 T6 T7

DON’T CARE

NOP

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

READs

READ bursts are initiated with a READ command, as shown in Figure 12 on page 28.

The starting column and bank addresses are provided with the READ command and

auto precharge is either enabled or disabled for that burst access. If auto precharge is

enabled, the row being accessed is precharged at the completion of the burst.

Note: For the READ commands used in the following illustrations, auto precharge is dis-

abled.

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 nominally at the next positive or negative clock edge (i.e., at the

next crossing of CK and CK#). Figure 13 on page 29 shows general timing for each possi-

ble CAS latency setting. DQS is driven by the DDR SDRAM along with output data. The

initial LOW state on DQS is known as the read preamble; the LOW state coincident with

the last data-out element is known as the read postamble.

Upon completion of a burst, assuming no other commands have been initiated, the DQs

will go High-Z. A detailed explanation of tDQSQ (valid data-out skew), tQH (data-out

window hold), and the valid data window are depicted in Figure 40 on page 77 and

Figure 41 on page 78. A detailed explanation of tDQSCK (DQS transition skew to CK) and

tAC (data-out transition skew to CK) is depicted in Figure 42 on page 79.

Data from any READ burst may be concatenated with or truncated with data from a sub-

sequent READ command. In either case, a continuous flow of data can be maintained.

The first data element from the new burst follows either the last element of a completed

burst or the last desired data element of a longer burst which is being truncated. The

new READ command should be issued x cycles after the first READ command, where x

equals the number of desired data element pairs (pairs are required by the 2n-prefetch

architecture). This is shown in Figure 14 on page 30. A READ command can be initiated

on any clock cycle following a previous READ command. Nonconsecutive read data is

illustrated in Figure 15, Nonconsecutive READ Bursts, on page 31. Full-speed random

read accesses within a page (or pages) can be performed as shown in Figure 16, Random

READ Accesses, on page 32.

Data from any READ burst may be truncated with a BURST TERMINATE command, as

shown in Figure 17 on page 33. The BURST TERMINATE latency is equal to the read

(CAS) latency; i.e., the BURST TERMINATE command should be issued x cycles after the

READ command, where x equals the number of desired data element pairs (pairs are

required by the 2n-prefetch architecture).

Data from any READ burst must be completed or truncated before a subsequent WRITE

command can be issued. If truncation is necessary, the BURST TERMINATE command

must be used, as shown in Figure 18 on page 34. The tDQSS (NOM) case is shown; the

tDQSS (MAX) case has a longer bus idle time. (tDQSS [MIN] and tDQSS [MAX] are

defined in the section on WRITEs.)

A READ burst may be followed by, or truncated with, a PRECHARGE command to the

same bank provided that auto precharge was not activated.

The PRECHARGE command should be issued x cycles after the READ command, where

x equals the number of desired data element pairs (pairs are required by the 2n-prefetch

architecture). This is shown in Figure 19 on page 35. Following the PRECHARGE com-

mand, a subsequent command to the same bank cannot be issued until both tRAS and

tRP have been met. Note that part of the row precharge time is hidden during the access

of the last data elements.

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 12: READ Command

CS#

WE#

CAS#

RAS#

CKE

x4: A0–A9, A11

x8: A0–A9

x16: A0–A8

A10

BA0,1

HIGH

EN AP

DIS AP

x4: A12

x8: A11, A12

x16: A9, A11, A12

CK#

CA = Column Address

BA = Bank Address

EN AP = Enable Auto Precharge

DIS AP = Disable Auto Precharge

DON’T CARE

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 13: READ Burst

Notes: 1. DO n = data-out from column n.

2. Burst length = 4.

3. Three subsequent elements of data-out appear in the programmed order following DO n.

4. Shown with nominal tAC, tDQSCK, and tDQSQ.

CK#

COMMAND

READ NOP NOP NOP NOP NOP

ADDRESS

Bank a,

Col n

READ NOP NOP NOP NOP NOP

Bank a,

Col n

CL = 2

CK#

COMMAND

ADDRESS

DQS

CL = 2.5

DQS

T0 T1 T2 T3T2n T3n T4 T5

READ NOP NOP NOP NOP NOP

Bank a,

Col n

CK#

COMMAND

ADDRESS

DQS

CL = 3

T0 T1 T2 T3 T3n T4 T5

DON’T CARE TRANSITIONING DATA

T4n

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 14: Consecutive READ Bursts

Notes: 1. DO n (or b) = data-out from column n (or column b).

2. Burst length = 4 or 8 (if 4, the bursts are concatenated; if 8, the second burst interrupts the

first).

3. Three subsequent elements of data-out appear in the programmed order following DO n.

4. Three (or seven) subsequent elements of data-out appear in the programmed order fol-

lowing DO b.

5. Shown with nominal tAC, tDQSCK, and tDQSQ.

6. Example applies only when READ commands are issued to the same device.

CK#

COMMAND READ NOP READ NOP NOP NOP

ADDRESS Bank,

Col n

Bank,

Col b

COMMAND READ NOP READ NOP NOP NOP

ADDRESS Bank,

Col n

Bank,

Col b

CL = 2

CK#

COMMAND

ADDRESS

DQS

CL = 2.5

DQS

T0 T1 T2 T3T2n T3n T4 T5T4n T5n

DON’T CARE TRANSITIONING DATA

COMMAND READ NOP READ NOP NOP NOP

ADDRESS Bank,

Col n

Bank,

Col b

CK#

COMMAND

ADDRESS

DQS

CL = 3

T0 T1 T2 T3 T3n T4 T5T4n T5n

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 15: Nonconsecutive READ Bursts

Notes: 1. DO n (or b) = data-out from column n (or column b).

2. Burst length = 4 or 8 (if 4, the bursts are concatenated; if 8, the second burst interrupts the

first).

3. Three subsequent elements of data-out appear in the programmed order following DO n.

4. Three (or seven) subsequent elements of data-out appear in the programmed order fol-

lowing DO b.

5. Shown with nominal tAC, tDQSCK, and tDQSQ.

CK#

COMMAND READ NOP NOP NOP NOP NOP

ADDRESS Bank,

Col n

READ

Bank,

Col b

COMMAND

ADDRESS

CL = 2

CK#

COMMAND

ADDRESS

DQS

CL = 2.5

DQS

T0 T1 T2 T3T2n T3n T4 T5 T5n T6

READ NOP NOP NOP NOP NOP

Bank,

Col n

READ

Bank,

Col b

T0 T1 T2 T3T2n T3n T4 T5 T5n T6

DON’T CARE TRANSITIONING DATA

COMMAND

ADDRESS

CK#

COMMAND

ADDRESS

DQS

CL = 3

READ NOP NOP NOP NOP NOP

Bank,

Col n

READ

Bank,

Col b

T0 T1 T2 T3 T3n T4 T5T4n T6

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 16: Random READ Accesses

Notes: 1. DO n (or x or b or g) = data-out from column n (or column x or column b or column g).

2. Burst length = 2, 4 or 8 (if 4 or 8, the following burst interrupts the previous).

3. n' or x' or b' or g' indicates the next data-out following DO n or DO x or DO b or DO g,

respectively.

4. READs are to an active row in any bank.

5. Shown with nominal tAC, tDQSCK, and tDQSQ.

CK#

COMMAND READ READ READ NOP NOP

ADDRESS Bank,

Col n

Bank,

Col x

Bank,

Col b

Bank,

Col x

Bank,

Col b

READ

Bank,

Col g

COMMAND

ADDRESS

CL = 2

CK#

COMMAND

ADDRESS

DQS

CL = 2.5

DQS

T0 T1 T2 T3T2n T3n T4 T5T4n T5n

READ READ READ NOP NOP

Bank,

Col n

READ

Bank,

Col g

T0 T1 T2 T3T2n T3n T4 T5T4n T5n

DON’T CARE TRANSITIONING DATA

Bank,

Col x

Bank,

Col b

COMMAND

ADDRESS

CK#

COMMAND

ADDRESS

DQS

CL = 3

READ READ READ NOP NOP

Bank,

Col n

READ

Bank,

Col g

T0 T1 T2 T3 T3n T4 T5T4n T5n

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 17: Terminating a READ Burst

Notes: 1. DO n = data-out from column n.

2. Burst length = 4 or 8.

3. Subsequent element of data-out appears in the programmed order following DO n.

4. Shown with nominal tAC, tDQSCK, and tDQSQ.

5. BST = BURST TERMINATE command; page remains open.

CK#

COMMAND

READ BST

NOP NOP NOP NOP

ADDRESS

Bank a,

Col n

READ BST

NOP NOP NOP NOP

Bank a,

Col n

CL = 2

CK#

COMMAND

ADDRESS

DQS

CL = 2.5

DQS

T0 T1 T2 T3T2n T4 T5

DON’T CARE TRANSITIONING DATA

READ BST

NOP NOP NOP NOP

Bank a,

Col n

CK#

COMMAND

ADDRESS

DQS

CL = 3

T0 T1 T2 T3 T3n T4 T5

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 18: READ to WRITE

Notes: 1. DO n = data-out from column n.

2. DI b = data-in from column b.

3. Burst length = 4 in the cases shown (applies for bursts of 8 as well; if the burst length is 2,

the BST command shown can be NOP).

4. One subsequent element of data-out appears in the programmed order following DO n.

5. Data-in elements are applied following DI b in the programmed order.

6. Shown with nominal tAC, tDQSCK, and tDQSQ.

7. BST = BURST TERMINATE command;

8. page remains open.

CK#

COMMAND READ BST7NOP NOP NOP

ADDRESS Bank,

Col n

WRITE

Bank,

Col b

T0 T1 T2 T3T2n T4 T5T4n T5n

CL = 2

DQS

(NOM)

DQSS

CK#

COMMAND READ BST7NOP WRITE NOP

ADDRESS Bank a,

Col n

NOP

T0 T1 T2 T3T2n T4 T5 T5n

CL = 2.5

DQS

DON’T CARE TRANSITIONING DATA

(NOM)

DQSS

CK#

COMMAND READ BST7NOP WRITE NOP

ADDRESS Bank a,

Col n

NOP

T0 T1 T2 T3 T4 T5 T5n

CL = 3

DQS

T3n

(NOM)

DQSS

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 19: READ to PRECHARGE

Notes: 1. DO n = data-out from column n.

2. Burst length = 4, or an interrupted burst of 8.

3. Three subsequent elements of data-out appear in the programmed order following DO n.

4. Shown with nominal tAC, tDQSCK, and tDQSQ.

5. READ to PRECHARGE equals two clocks, which allows two data pairs of data-out.

6. A READ command with AUTO-PRECHARGE enabled, provided tRAS (MIN) is met, would

cause a precharge to be performed at x number of clock cycles after the READ command,

where x = BL / 2.

7. An active command to the same bank is only allowed if tRC (MIN) has been satisfied.

8. PRE = PRECHARGE command; ACT = ACTIVE command.

CK#

COMMAND6READ NOP PRE NOP NOP ACT

ADDRESS Bank a,

Col n

Bank a,

(a or all)

Bank a,

Row

READ NOP PRE NOP NOP ACT

Bank a,

Col n

CL = 2 tRP

tRP

CK#

COMMAND6

ADDRESS

DQS

CL = 2.5

DQS

T0 T1 T2 T3T2n T3n T4 T5

Bank a,

(a or all)

Bank a,

Row

DON’T CARE TRANSITIONING DATA

READ NOP

Bank a,

Col n

tRP

CK#

COMMAND6

ADDRESS

DQS

CL = 3

T0 T1 T2 T3 T4nT3n T4 T5

PRE NOP ACT

Bank a,

(a or all)

NOP

Bank a,

Row

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

WRITEs

WRITE bursts are initiated with a WRITE command, as shown in Figure 20.

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 and after the tWR

time.

Note: For the WRITE commands used in the following illustrations, auto precharge is dis-

abled.

During WRITE bursts, the first valid data-in element will be registered on the first rising

edge of DQS following the WRITE command, and subsequent data elements will be reg-

istered on successive edges of DQS. The LOW state on DQS between the WRITE com-

mand and the first rising edge is known as the write preamble; the LOW state on DQS

following the last data-in element is known as the write postamble.

The time between the WRITE command and the first corresponding rising edge of

DQS (tDQSS) is specified with a relatively wide range (from 75 percent to 125 per-

cent of one clock cycle and 72 percent to 128 percent for DDR400). All of the WRITE

diagrams show the nominal case, and where the two extreme cases (i.e., tDQSS

[MIN] and tDQSS [MAX]) might not be intuitive, they have also been included.

Figure 21 on page 38 shows the nominal case and the extremes of tDQSS for a burst

of 4. Upon completion of a burst, assuming no other commands have been initiated,

the DQ will remain High-Z and any additional input data will be ignored.

Data for any WRITE burst may be concatenated with or truncated with a subsequent

WRITE command. In either case, a continuous flow of input data can be maintained.

The new WRITE command can be issued on any positive edge of clock following the pre-

vious WRITE command. The first data element from the new burst is applied after either

the last element of a completed burst or the last desired data element of a longer burst

which is being truncated. The new WRITE command should be issued x cycles after the

first WRITE command, where x equals the number of desired data element pairs (pairs

are required by the 2n-prefetch architecture).

Figure 22 on page 39 shows concatenated bursts of 4. An example of nonconsecutive

WRITEs is shown in Figure 23 on page 40. Full-speed random write accesses within a

page or pages can be performed as shown in Figure 24 on page 40.

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 20: WRITE Command

Data for any WRITE burst may be followed by a subsequent READ command. To follow a

WRITE without truncating the WRITE burst, tWTR should be met as shown in Figure 25

on page 41.

Data for any WRITE burst may be truncated by a subsequent READ command, as shown

in Figure 26 on page 42.

Note that only the data-in pairs that are registered prior to the tWTR period are written

to the internal array, and any subsequent data-in should be masked with DM, as shown

in Figure 27 on page 43.

Data for any WRITE burst may be followed by a subsequent PRECHARGE command. To

follow a WRITE without truncating the WRITE burst, tWR should be met as shown in

Figure 28 on page 44.

Data for any WRITE burst may be truncated by a subsequent PRECHARGE command, as

shown in Figure 29 on page 45 and Figure 30 on page 46. Note that only the data-in pairs

that are registered prior to the tWR period are written to the internal array, and any sub-

sequent data-in should be masked with DM as shown in Figures 29 and 30. After the

PRECHARGE command, a subsequent command to the same bank cannot be issued

until tRP is met.

CS#

WE#

CAS#

RAS#

CKE

A10

BA0, 1

HIGH

EN AP

DIS AP

CK#

CA = Column Address

BA = Bank Address

EN AP = Enable Auto Precharge

DIS AP = Disable Auto Prechar

DON’T CARE

x4: A0–A9, A11

x8: A0–A9

x16: A0–A8

x4: A12

x8: A11, A12

x16: A9, A11, A12

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 21: WRITE Burst

Notes: 1. DI b = data-in for column b.

2. Three subsequent elements of data-in are applied in the programmed order following DI

3. An uninterrupted burst of 4 is shown.

4. A10 is LOW with the WRITE command (auto precharge is disabled).

DQS

tDQSS (MAX)

tDQSS (NOM)

tDQSS (MIN)

tDQSS

CK#

COMMAND WRITE NOP NOP

ADDRESS Bank a,

Col b

NOP

T0 T1 T2 T3T2n

DQS

tDQSS

DQS

tDQSS

DQ DI

DON’T CARE TRANSITIONING DATA

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 22: Consecutive WRITE to WRITE

Notes: 1. DI b, etc., = data-in for column b, etc.

2. Three subsequent elements of data-in are applied in the programmed order following DI

3. Three subsequent elements of data-in are applied in the programmed order following DI

4. An uninterrupted burst of 4 is shown.

5. Each WRITE command may be to any bank.

CK#

COMMAND WRITE NOP WRITE NOP NOP

ADDRESS Bank,

Col b

NOP

Bank,

Col n

T0 T1 T2 T3T2n T4 T5T4nT3nT1n

DQS

DON’T CARE TRANSITIONING DATA

tDQSS

tDQSS (NOM)

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 23: Nonconsecutive WRITE to WRITE

Notes: 1. DI b, etc., = data-in for column b, etc.

2. Three subsequent elements of data-in are applied in the programmed order following DI b.

3. Three subsequent elements of data-in are applied in the programmed order following DI n.

4. An uninterrupted burst of 4 is shown.

5. Each WRITE command may be to any bank.

Figure 24: Random WRITE Cycles

Notes: 1. DI b, etc., = data-in for column b, etc.

2. b', etc., = the next data-in following DI b, etc., according to the programmed burst order.

3. Programmed burst length = 2, 4, or 8 in cases shown.

4. Each WRITE command may be to any bank.

CK#

COMMAND WRITE NOP NOP NOP NOP

ADDRESS Bank,

Col b

WRITE

Bank,

Col n

T0 T1 T2 T3T2n T4 T5T4nT1n T5n

DQS

tDQSS (NOM) tDQSS

DON’T CARE TRANSITIONING DATA

tDQSS (NOM)

CK#

COMMAND WRITE WRITE WRITE WRITE NOP

ADDRESS Bank,

Col b

Bank,

Col x

Bank,

Col n

Bank,

Col g

WRITE

Bank,

Col a

T0 T1 T2 T3T2n T4 T5T4nT1n T3n T5n

DQS

gDI

DON’T CARE TRANSITIONING DATA

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 25: WRITE to READ - Uninterrupting

Notes: 1. DI b = data-in for column b; DO n = data-out for column n.

2. Three subsequent elements of data-in are applied in the programmed order following DI

3. An uninterrupted burst of 4 is shown.

4. tWTR is referenced from the first positive CK edge after the last data-in pair.

5. The READ and WRITE commands are to the same device. However, the READ and WRITE

commands may be directed to different devices, in which case, tWTR is not required and

the READ command could be applied earlier.

6. A10 is LOW with the WRITE command (auto precharge is disabled).

tDQSS (NOM)

CK#

COMMAND WRITE NOP NOP READ NOP NOP

ADDRESS Bank a,

Col b

Bank a,

Col n

NOP

T0 T1 T2 T3T2n T4 T5T1n T6 T6n

tWTR

CL = 2

DQS

tDQSS

tDQSS (MIN) CL = 2

DQS

tDQSS

tDQSS (MAX) CL = 2

DQS

tDQSS

DON’T CARE TRANSITIONING DATA

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 26: WRITE to READ – Interrupting

Notes: 1. DI b = data-in for column;, DO n = data-out for column n.

2. An interrupted burst of 4 is shown; two data elements are written.

3. One subsequent element of data-in is applied in the programmed order following DI b.

4. tWTR is referenced from the first positive CK edge after the last data-in pair.

5. A10 is LOW with the WRITE command (auto precharge is disabled).

6. DQS is required at T2 and T2n (nominal case) to register DM.

7. If the burst of 8 was used, DM and DQS would be required at T3 and T3n because the

READ command would not mask these two data elements.

tDQSS (NOM)

CK#

COMMAND WRITE NOP NOP NOP NOP NOP

ADDRESS Bank a,

Col b

Bank a,

Col n

READ

T0 T1 T2 T3T2n T4 T5 T5nT1n T6 T6n

tWTR

CL = 2

DQS

tDQSS (MIN) CL = 2

DQS

tDQSS (MAX) CL = 2

DQS

DON’T CARE TRANSITIONING DATA

tDQSS

T3n

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 27: WRITE to READ – Odd Number of Data, Interrupting

Notes: 1. DI b = data-in for column b; DO n = data-out for column n.

2. An interrupted burst of 4 is shown; one data element is written.

3. tWTR is referenced from the first positive CK edge after the last desired data-in pair (not

the last two data elements).

4. A10 is LOW with the WRITE command (auto precharge is disabled).

5. DQS is required at T1n, T2, and T2n (nominal case) to register DM.

6. If the burst of 8 was used, DM and DQS would be required at T3–T3n because the READ

command would not mask these data elements.

tDQSS (NOM)

CK#

COMMAND WRITE NOP NOP NOP NOP NOP

ADDRESS Bank a,

Col b

Bank a,

Col n

READ

T0 T1 T2 T3T2n T4 T5T1n T6 T6nT5n

tWTR

CL = 2

DQS

tDQSS (MIN) CL = 2

DQS

tDQSS (MAX) CL = 2

DQS

DON’T CARE TRANSITIONING DATA

tDQSS

T3n

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 28: WRITE to PRECHARGE - Uninterrupting

Notes: 1. DI b = data-in for column b.

2. Three subsequent elements of data-in are applied in the programmed order following DI

3. An uninterrupted burst of 4 is shown.

4. tWR is referenced from the first positive CK edge after the last data-in pair.

5. The PRECHARGE and WRITE commands are to the same device. However, the PRECHARGE

and WRITE commands may be to different devices, in which case, tWR is not required and

the PRECHARGE command could be applied earlier.

6. A10 is LOW with the WRITE command (auto precharge is disabled).

7. PRE = PRECHARGE command.

tDQSS (NOM)

CK#

COMMAND WRITE NOP NOP NOP PRE7NOP

ADDRESS Bank a,

Col b

Bank,

(a or all)

NOP

T0 T1 T2 T3T2n T4 T5T1n T6

tWR tRP

DQS

tDQSS (MIN)

DQS

tDQSS (MAX)

DQS

DON’T CARE TRANSITIONING DATA

tDQSS

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 29: WRITE to PRECHARGE – Interrupting

Notes: 1. DI b = data-in for column b.

2. Subsequent element of data-in is applied in the programmed order following DI b.

3. An interrupted burst of 8 is shown; two data elements are written.

4. tWR is referenced from the first positive CK edge after the last data-in pair.

5. A10 is LOW with the WRITE command (auto precharge is disabled).

6. DQS is required at T4 and T4n (nominal case) to register DM.

7. If the burst of 4 was used, DQS and DM would not be required at T3, T3n, T4, and T4n.

8. PRE = PRECHARGE command.

tDQSS

tDQSS (NOM)

CK#

COMMAND WRITE NOP NOP PRE8NOP NOP

ADDRESS Bank a,

Col b

Bank,

(a or all)

NOP

T0 T1 T2 T3T2n T4 T5T1n T6

tWR tRP

DQS

tDQSS

tDQSS (MIN)

DQS

tDQSS

tDQSS (MAX)

DQS

DON’T CARE TRANSITIONING DATA

T3n T4n

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 30: WRITE to PRECHARGE – Odd Number of Data – Interrupting

Notes: 1. DI b = data-in for column b.

2. An interrupted burst of 8 is shown; one data element is written.

3. tWR is referenced from the first positive CK edge after the last data-in pair.

4. A10 is LOW with the WRITE command (auto precharge is disabled).

5. DQS is required at T4 and T4n (nominal case) to register DM.

6. If the burst of 4 was used, DQS and DM would not be required at T3, T3n, T4, and T4n.

7. PRE = PRECHARGE command.

tDQSS

tDQSS (NOM)

CK#

COMMAND WRITE NOP NOP PRE7NOP NOP

ADDRESS Bank a,

Col b

Bank,

(a or all)

NOP

T0 T1 T2 T3T2n T4 T5T1n T6

tWR tRP

DQS

tDQSS

tDQSS (MIN)

DQS

tDQSS

tDQSS (MAX)

DQS

DON’T CARE TRANSITIONING DATA

T3n T4n

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

PRECHARGE

The PRECHARGE command, as shown in Figure 31, 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 subse-

quent row access some specified time (tRP) 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. When all

banks are to be precharged, inputs BA0, BA1 are treated as “Don’t Care.” Once a bank has

been precharged, it is in the idle state and must be activated prior to any READ or WRITE

commands being issued to that bank.

Figure 31: PRECHARGE Command

Power-Down (CKE Not Active)

Unlike SDR SDRAMs, DDR SDRAMs require CKE to be active at all times that an access is

in progress, from the issuing of a READ or WRITE command until completion of the

access. Thus, a clock suspend is not supported. For READs, an access completion is

defined when the read postamble is satisfied; for WRITEs, an access completion is

defined when the write recovery time (tWR) is satisfied.

Power-down, shown in Figure 32, Power-Down, on page 48, is entered when CKE is reg-

istered LOW and all of the criteria listed in Table 10, on page 48, are met. 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 any bank, this mode is referred to as

active power-down. Entering power-down deactivates the input and output buffers,

excluding CK, CK#, and CKE. For maximum power savings, the DLL is frozen during pre-

CS#

WE#

CAS#

RAS#

CKE

A10

BA0,1

HIGH

ALL BANKS

ONE BANK

A0–A9, A11, A12

CK#

BA = Bank Address (if A10 is LOW;

otherwise “Don’t Care”)

DON’T CARE

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

charge power-down mode. Exiting power-down requires the device to be at the same

voltage and frequency as when it entered power-down. However, power-down duration

is limited by the refresh requirements of the device (tREFC).

While in power-down, CKE LOW and a stable clock signal must be maintained at the

inputs of the DDR SDRAM, while all other input signals are “Don’t Care.” The power-

down state is synchronously exited when CKE is registered HIGH (in conjunction with a

NOP or DESELECT command). A valid executable command may be applied one clock

cycle later.

Figure 32: Power-Down

Notes: 1. CKEn is the logic state of CKE at clock edge n; CKEn-1 was the state of CKE at the previous

clock edge.

2. Current state is the state of the DDR SDRAM immediately prior to clock edge n.

3. COMMANDn is the command registered at clock edge n, and ACTIONn is a result of COM-

MANDn.

4. All states and sequences not shown are illegal or reserved.

5. CKE must not drop LOW during a column access. For a READ, this means CKE must stay

HIGH until after the read postamble time; for a WRITE, CKE must stay HIGH until the

WRITE recovery time (tWR) has been met.

6. Once initialized, including during self refresh mode, VREF must be powered within the

specified range.

7. Upon exit of the self refresh mode, the DLL is automatically enabled, but a DLL reset must

still occur. A minimum of 200 clock cycles is needed before applying a READ command for

the DLL to lock. DESELECT or NOP commands should be issued on any clock edges occur-

ring during the tXSNR period.

Table 10: Truth Table – CKE

Notes: 1–6

CKEn-1 CKEnCurrent State CommandnActionnNotes

L L Power-Down X Maintain Power-Down

Self Refresh X Maintain Self Refresh

L H Power-Down DESELECT or NOP Exit Power-Down

Self Refresh DESELECT or NOP Exit Self Refresh 7

H L All Banks Idle DESELECT or NOP Precharge Power-Down Entry

Bank(s) Active DESELECT or NOP Active Power-Down Entry

All Banks Idle AUTO REFRESH Self Refresh Entry

H H See Table 11 on page 49

tIS tIS

No READ/WRITE

access in progress Exit power-down mode

Enter power-down mode

CKE

CK#

COMMAND NOP

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

NOP VALID

T0 T1 T2 Ta0 Ta1 Ta2

VALID

DON’T CARE

VALID

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

Notes: 1. This table applies when CKEn-1 was HIGH and CKEn is HIGH (see Table 10 on page 48) and

after tXSNR 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 tRP has been met.

• Row Active: A row in the bank has been activated, and tRCD 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 Table 11, Truth Table – Current State

Bank n – Command to Bank n, on page 49 and according to Table 12, Truth Table – Current

State Bank n– Command to Bank m, on page 51.

• Precharging: Starts with registration of a PRECHARGE command and ends when

tRP is met. Once tRP is met, the bank will be in the idle state.

• Row Activating: Starts with registration of an ACTIVE command and ends when

tRCD is met. Once tRCD 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 tRP has beenmet. Once tRP 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 tRP has been met. Once tRP is met,

the bank will be in the idle state.

5. The following states must not be interrupted by any executable command; COMMAND

INHIBIT or NOP commands must be applied on each positive clock edge during these

states.

Table 11: Truth Table – 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 DESELECT (NOP/continue previous operation)

LHH H

NO OPERATION (NOP/continue previous operation)

Idle L L H H ACTIVE (select and activate row)

LL L H

AUTO REFRESH 7

LL L L

LOAD MODE REGISTER 7

Row Active L H L H READ (select column and start READ burst) 10

LH L L

WRITE (select column and start WRITE burst) 10

LLH L

PRECHARGE (deactivate row in bank or banks) 8

Read

(Auto-

Precharge

Disabled)

LH L H

READ (select column and start new READ burst) 10

LH L L

WRITE (select column and start WRITE burst) 10, 12

LLH L

PRECHARGE (truncate READ burst, start PRECHARGE) 8

LHH L

BURST TERMINATE 9

Write

(Auto-

Precharge

Disabled)

LH L H

READ (select column and start READ burst) 10, 11

LH L L

WRITE (select column and start new WRITE burst) 10

LLH L

PRECHARGE (truncate WRITE burst, start PRECHARGE) 8, 11

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

• Refreshing: Starts with registration of an AUTO REFRESH command and ends

when tRFC is met. Once tRFC is met, the DDR SDRAM will be in the all banks idle

state.

• Accessing Mode Register: Starts with registration of a LOAD MODE REGISTER

command and ends when tMRD has been met. Once tMRD is met, the DDR

SDRAM will be in the all banks idle state.

• Precharging All: Starts with registration of a PRECHARGE ALL command and ends

when tRP is met. Once tRP 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 and bursts are not in progress.

8. May or may not be bank-specific; if multiple banks are to be precharged, each must be in a

valid state for precharging.

9. Not bank-specific; BURST TERMINATE affects the most recent READ 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. Requires appropriate DM masking.

12. A WRITE command may be applied after the completion of the READ burst; otherwise, a

BURST TERMINATE must be used to end the READ burst prior to asserting a WRITE com-

mand.

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

Notes: 1. This table applies when CKEn-1 was HIGH and CKEn is HIGH (see Truth Table 2) and after

tXSNR 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 cov-

ered in the notes below.

3. Current state definitions:

• Idle: The bank has been precharged, and tRP has been met.

• Row Active: A row in the bank has been activated, and tRCD 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 with Auto Precharge Enabled: See following text – 3a

• Write with Auto Precharge Enabled: See following text – 3a

a.The read with auto precharge enabled or write with auto precharge enabled states

can each be broken into two parts: the access period and the precharge period. For

read with auto precharge, the precharge period is defined as if the same burst was

executed with auto precharge disabled and then followed with the earliest possible

PRECHARGE command that still accesses all of the data in the burst. For write with

auto precharge, the precharge period begins when tWR ends, with tWR measured as if

auto precharge was disabled. The access period starts with registration of the com-

mand and ends where the precharge period (or tRP) begins.

Table 12: Truth Table – 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 HX X X

DESELECT (NOP/continue previous operation)

LHH H

NO OPERATION (NOP/continue previous operation)

Idle XX X X

Any Command Otherwise Allowed to Bank m

Row

Activating,

Active, or

Precharging

LLHH

ACTIVE (select and activate row)

LH L H

READ (select column and start READ burst) 7

LH L L

WRITE (select column and start WRITE burst) 7

LLH L

PRECHARGE

Read

(Auto-Precharge

Disabled)

LLHH

ACTIVE (select and activate row)

LH L H

READ (select column and start new READ burst) 7

LH L L

WRITE (select column and start WRITE burst) 7, 9

LLH L

PRECHARGE

Write

(Auto- Precharge

Disabled)

LLHH

ACTIVE (select and activate row)

LH L H

READ (select column and start READ burst) 7, 8

LH L L

WRITE (select column and start new WRITE burst) 7

LLH L

PRECHARGE

Read

(With Auto-

Precharge)

LLHH

ACTIVE (select and activate row)

LH L H

READ (select column and start new READ burst) 7, 3a

LH L L

WRITE (select column and start WRITE burst) 7, 9, 3a

LLH L

PRECHARGE

Write

(With Auto-

Precharge)

LLHH

ACTIVE (select and activate row)

LH L H

READ (select column and start READ burst) 7, 3a

LH L L

WRITE (select column and start new WRITE burst) 7, 3a

LLH L

PRECHARGE

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Operations

This device supports concurrent auto precharge such that when a READ with

auto precharge is enabled or a WRITE with auto precharge is enabled any

command to other banks is allowed, as long as that command does not inter-

rupt the read or write data transfer already in process. In either case, all other

related limitations apply (e.g., contention between read data and write data

must be avoided).

b.The minimum delay from a READ or WRITE command with auto precharge enabled, to

a command to a different bank, is summarized below.

4. AUTO 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 listed in the Command/Action column include READs or WRITEs with

auto precharge enabled and READs or WRITEs with auto precharge disabled.

8. Requires appropriate DM masking.

9. A WRITE command may be applied after the completion of the READ burst; otherwise, a

BURST TERMINATE must be used to end the READ burst prior to asserting a WRITE com-

mand.

Table 13: Minimum Delay Summary

CLRU = CAS Latency (CL) rounded up to the next integer BL = Bust length

From Command To Command Minimum Delay (with Concurrent Auto Precharge)

WRITE w/AP READ or READ w/AP [1 + (BL/2)] * tCK + tWTR

WRITE or WRITE w/AP (BL/2) * tCK

PRECHARGE 1 tCK

ACTIVE 1 tCK

READ w/AP READ or READ w/AP (BL/2) * tCK

WRITE or WRITE w/AP [CLRU + (BL/2)] *tCK

PRECHARGE 1 tCK

ACTIVE 1 tCK

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Absolute Maximum Ratings

Stresses greater than those listed 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 reli-

ability.

VDD Supply Voltage Relative to Vss. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -1V to +3.6V

VDDQ Supply Voltage Relative to VSS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -1V to +3.6V

VREF and Inputs Voltage Relative to VSS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -1V to +3.6V

I/O Pins Voltage Relative to VSS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-0.5V to VDDQ +0.5V

Operating Temperature, TA ambient, Commercial) . . . . . . . . . . . . . . . . . . . . . . .0°C to +70°C

Operating Temperature, TA (ambient, Industrial). . . . . . . . . . . . . . . . . . . . . . . -40°C to +85°C

Storage Temperature (plastic) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -55°C to +150°C

Short Circuit Output Current. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50mA

Table 14: DC Electrical Characteristics and Operating Conditions (-6, -6T, -75E, -75Z, -75)

0°C ≤ TA ≤ +70°C; VDDQ = +2.5V ±0.2V, VDD = +2.5V ±0.2V; notes: 1–5, 16; notes appear on pages 69–74

Parameter/Condition Symbol Min Max Units Notes

Supply Voltage VDD 2.3 2.7 V 36, 41

I/O Supply Voltage VDDQ2.3 2.7 V 36,41, 44

I/O Reference Voltage VREF 0.49 x VDDQ 0.51 x VDDQ V 6, 44

I/O Termination Voltage (system) VTT VREF - 0.04 VREF + 0.04 V7, 44

Input High (Logic 1) Voltage VIH(DC)VREF + 0.15 VDD + 0.3 V28

Input Low (Logic 0) Voltage VIL(DC)-0.3 VREF - 0.15 V28

INPUT LEAKAGE CURRENT

Any input 0V ≤ VIN ≤ VDD, VREF PIN 0V ≤ VIN ≤ 1.35V

(All other pins not under test = 0V)

II-2 2 µA

OUTPUT LEAKAGE CURRENT

(DQs are disabled; 0V ≤ VOUT ≤ VDDQ)

IOZ -5 5 µA

OUTPUT LEVELS: Full drive option - x4, x8, x16

High Current (VOUT = VDDQ - 0.373V, minimum VREF,

minimum VTT)

IOH -16.8 - mA 37, 39

Low Current (VOUT = 0.373V, maximum VREF, maximum VTT)IOL 16.8 - mA

OUTPUT LEVELS: Reduced drive option - x16 only

High Current (VOUT = VDDQ - 0.763V, minimum VREF,

minimum VTT)

IOHR -9 - mA 38, 39

Low Current (VOUT = 0.763V, maximum VREF, maximum VTT)IOLR 9-mA

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Absolute Maximum Ratings

Table 15: DC Electrical Characteristics and Operating Conditions (-5B DDR400)

0°C ≤ TA ≤ +70°C; VDDQ = +2.6V ±0.1V, VDD = +2.6V ±0.1V; notes: 1–5, 16, and 53; Notes appear on page 69-74

Parameter/Condition Symbol Min Max Units Notes

Supply Voltage VDD 2.5 2.7 V 36, 41, 52

I/O Supply Voltage VDDQ2.5 2.7 V 36,41, 44,

I/O Reference Voltage VREF 0.49 x VDDQ 0.51 x VDDQV 6, 44

I/O Termination Voltage (system) VTT VREF - 0.04 VREF + 0.04 V7, 44

Input High (Logic 1) Voltage VIH(DC)VREF + 0.15 VDD + 0.3 V28

Input Low (Logic 0) Voltage VIL(DC)-0.3 VREF - 0.15 V28

INPUT LEAKAGE CURRENT

Any input 0V ≤ VIN ≤ VDD, VREF PIN 0V ≤ VIN ≤ 1.35V

(All other pins not under test = 0V)

II-2 2 µA

OUTPUT LEAKAGE CURRENT

(DQs are disabled; 0V ≤ VOUT ≤ VDDQ)

IOZ -5 5 µA

OUTPUT LEVELS: Full drive option - x4, x8, x16

High Current (VOUT = VDDQ - 0.373V, minimum VREF,

minimum VTT)

IOH -16.8 - mA 37, 39

Low Current (VOUT = 0.373V, maximum VREF,

maximum VTT)

IOL 16.8 - mA

OUTPUT LEVELS: Reduced drive option - x16 only

High Current (VOUT = VDDQ - 0.763V, minimum VREF,

minimum VTT)

IOHR -9 - mA 38, 39

Low Current (VOUT = 0.763V, maximum VREF,

maximum VTT)

IOLR 9-mA

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Absolute Maximum Ratings

Figure 33: Input Voltage Waveform

Table 16: AC Input Operating Conditions

0°C ≤ TA ≤ +70°C; VDDQ = +2.5V ±0.2V, VDD = +2.5V ±0.2V (VDDQ = +2.6V ±0.1V, VDD = +2.6V ±0.1V for

DDR400); notes: 1–5, 14, 16; notes appear on pages 69–74

Parameter/Condition Symbol Min Max Units Notes

Input High (Logic 1) Voltage VIH(AC)VREF + 0.310 - V 14, 28, 40

Input Low (Logic 0) Voltage VIL(AC)-VREF - 0.310 V 14, 28, 40

I/O Reference Voltage VREF(AC) 0.49 x VDDQ 0.51 x VDDQV6

0.940V

1.100V

1.200V

1.225V

1.250V

1.275V

1.300V

1.400V

1.560V

VILAC

VILDC

VREF -AC Noise

VREF -DC Error

VREF +DC Error

VREF +AC Noise

Receiver

Transmitter

VIHDC

VIHAC

VOH (MIN) (1.670V1 for SSTL_2 termination)

VINAC - Provides margin

between VOL (MAX) and VILAC

VSSQ

VDDQ (2.3V minimum)

VOL (MAX) (0.83V2 for

SSTL_2 termination)

System Noise Margin (Power/Ground,

Crosstalk, Signal Integrity Attenuation)

NOTE:

1. VOH (MIN) with test load is 1.927V

2. VOL (MAX) with test load is 0.373V

3. For Non-DDR400 devices, numbers

in diagram reflect nomimal values

utilizing circuit below.

Reference

Point

25Ω

VTT

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Absolute Maximum Ratings

Figure 34: SSTL_2 Clock Input

Notes: 1. This provides a minimum of 1.15V to a maximum of 1.35V and is always half of VDDQ.

2. CK and CK# must cross in this region.

3. CK and CK# must meet at least VID(DC) MIN when static and is centered around VMP(DC)

4. CK and CK# must have a minimum 700mv peak-to-peak swing.

5. CK or CK# may not be more positive than VDDQ + 0.3V or more negative than Vss - 0.3V.

6. For AC operation, all DC clock requirements must also be satisfied.

7. Numbers in diagram reflect nominal values for non-DDR400 devices.

Table 17: Clock Input Operating Conditions

0°C ≤ TA ≤ +70°C; VDDQ = +2.5V ±0.2V, VDD = +2.5V ±0.2V (VDDQ = +2.6V ±0.1V, VDD = +2.6V ±0.1V for

DDR400); notes: 1–5, 15, 16, 30; notes appear on pages 69–74

Parameter/Condition Symbol Min Max Units Notes

Clock Input Midpoint Voltage; CK and CK# VMP(DC)1.15 1.35 V 6, 9

Clock Input Voltage Level; CK and CK# VIN(DC)-0.3 VDDQ + 0.3 V6

Clock Input Differential Voltage; CK and CK# VID(DC)0.36 VDDQ + 0.6 V6, 8

Clock Input Differential Voltage; CK and CK# VID(AC)0.7 VDDQ + 0.6 V8

Clock Input Crossing Point Voltage; CK and CK# VIX(AC) 0.5 x VDDQ - 0.2 0.5 x VDDQ + 0.2 V9

CK#

2.80V

Maximum Clock Level

Minimum Clock Level

- 0.30V

1.25V

1.45V

1.05V

(AC)

(DC)

(DC) V

(AC)

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Absolute Maximum Ratings

Table 18: Capacitance (x4, x8 TSOP)

Note: 13; notes appear on pages 69–74

Parameter Symbol Min Max Units Notes

Delta Input/Output Capacitance: DQ0–DQ3 (x4), DQ0–DQ7 (x8) DCIO –0.50pF 24

Delta Input Capacitance: Command and Address DCI1–0.50pF 29

Delta Input Capacitance: CK, CK# DCI2–0.25pF 29

Input/Output Capacitance: DQs, DQS, DM CIO 4.0 5.0 pF

Input Capacitance: Command and Address CI12.0 3.0 pF

Input Capacitance: CK, CK# CI22.0 3.0 pF

Input Capacitance: CKE CI32.0 3.0 pF

Table 19: Capacitance (x16 TSOP)

Note: 13; notes appear on pages 69–74

Parameter Symbol Min Max Units Notes

Delta Input/Output Capacitance: DQ0–DQ7, LDQS, LDM DCIOL –0.50pF 24

Delta Input/Output Capacitance: DQ8–DQ15, UDQS, UDM DCIOU –0.50pF 24

Delta Input Capacitance: Command and Address DCI1–0.50pF 29

Delta Input Capacitance: CK, CK# DCI2–0.25pF 29

Input/Output Capacitance: DQ, LDQS, UDQS, LDM, UDM CIO 4.0 5.0 pF

Input Capacitance: Command and Address CI12.0 3.0 pF

Input Capacitance: CK, CK# CI22.0 3.0 pF

Input Capacitance: CKE CI32.0 3.0 pF

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Absolute Maximum Ratings

Table 20: IDD Specifications and Conditions (x4, x8; -5B)

0°C ≤ TA ≤ +70°C; (VDDQ = +2.6V ±0.1V, VDD = +2.6V ±0.1V); notes: 1–5, 10, 12, 14, 46; notes appear on

pages 69–74; See also Table 26, Idd Test Cycle Times, on page 64

MAX

PARAMETER/CONDITION SYMBOL -5B UNITS NOTES

OPERATING CURRENT: One bank; active precharge;

tRC = tRC (MIN); tCK = tCK (MIN); DQ, DM, and DQS inputs changing once

per clock cycle; address and control inputs changing once every two clock

cycles

IDD0135 mA 22,47

OPERATING CURRENT: One bank; active-read precharge;

burst = 4; tRC = tRC (MIN); tCK = tCK (MIN); IOUT = 0mA; address and

control inputs changing once per clock cycle

IDD1170 mA 22, 47

PRECHARGE POWER-DOWN STANDBY CURRENT: All banks idle; power-

down mode; tCK = tCK (MIN); CKE = (LOW)

IDD2P 4 mA 23, 32, 49

IDLE STANDBY CURRENT: CS# = HIGH; all banks are idle;

tCK = tCK (MIN); CKE = HIGH; address and other control inputs changing

once per clock cycle; VIN = VREF for DQ, DQS, and DM

IDD2F 60 mA 50

ACTIVE POWER-DOWN STANDBY CURRENT: One bank active;

power-down mode; tCK = tCK (MIN); CKE = LOW

IDD3P 40 mA 23, 32, 49

ACTIVE STANDBY CURRENT: CS# = HIGH; CKE = HIGH;

one bank active; tRC = tRAS (MAX); tCK = tCK (MIN); DQ, DM, and DQS

inputs changing twice per clock cycle; address and other control inputs

changing once per clock cycle

IDD3N 70 mA 22

OPERATING CURRENT: Burst = 2; READs; continuous burst;

one bank active; address and control inputs changing once per clock cycle;

tCK = tCK (MIN); IOUT = 0mA

IDD4R 200 mA 22, 47

OPERATING CURRENT: Burst = 2; WRITEs; continuous burst;

one bank active; address and control inputs changing once per clock cycle;

tCK = tCK (MIN); DQ, DM, and DQS inputs changing twice per clock cycle

IDD4W 195 mA 22

AUTO REFRESH BURST CURRENT: tREFC =tRC (MIN) IDD5260 mA 49

tREFC = 7.8µs IDD5A 6 mA 27, 49

SELF REFRESH CURRENT: CKE ≤ 0.2V Standard IDD64mA11

Low power (L) IDD6A 2mA11

OPERATING CURRENT: Four-bank interleaving READs

(Burst = 4) with auto precharge, tRC = minimum tRC allowed;

tCK = tCK (MIN); address and control inputs change only during active

READ or WRITE commands

IDD7470 mA 22, 48

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Absolute Maximum Ratings

Table 21: IDD Specifications and Conditions (x4, x8; -6/-6T/-75E)

0°C ≤ TA ≤ +70°C; VDDQ = +2.5V ±0.2V, VDD = +2.5V ±0.2V; notes: 1–5, 10, 12, 14, 46; notes appear on

pages 69–74; See also Table 26, Idd Test Cycle Times, on page 64

Max

Parameter/Condition Symbol -6/6T -75E Units Notes

OPERATING CURRENT: One bank; active precharge;

tRC = tRC (MIN); tCK = tCK (MIN); DQ, DM, and DQS inputs

changing once per clock cycle; address and control inputs changing

once every two clock cycles

IDD0125 125 mA 22, 47

OPERATING CURRENT: One bank; active-read precharge;

burst = 4; tRC = tRC (MIN); tCK = tCK (MIN); IOUT = 0mA; address

and control inputs changing once per clock cycle

IDD1170 160 mA 22, 47

PRECHARGE POWER-DOWN STANDBY CURRENT: All banks idle;

power-down mode; tCK = tCK (MIN); CKE = (LOW)

IDD2P 4 4 mA 23, 32, 49

IDLE STANDBY CURRENT: CS# = HIGH; all banks are idle;

tCK = tCK (MIN); CKE = HIGH; address and other control inputs

changing once per clock cycle; VIN = VREF for DQ, DQS, and DM

IDD2F 50 45 mA 50

ACTIVE POWER-DOWN STANDBY CURRENT: One bank active;

power-down mode; tCK = tCK (MIN); CKE = LOW

IDD3P 30 25 mA 23, 32, 49

ACTIVE STANDBY CURRENT: CS# = HIGH; CKE = HIGH;

one bank active; tRC = tRAS (MAX); tCK = tCK (MIN); DQ, DM, and

DQS inputs changing twice per clock cycle; address and other

control inputs changing once per clock cycle

IDD3N 60 50 mA 22

OPERATING CURRENT: Burst = 2; READs; continuous burst;

one bank active; address and control inputs changing once per

clock cycle; tCK = tCK (MIN); IOUT = 0mA

IDD4R 175 150 mA 22, 47

OPERATING CURRENT: Burst = 2; WRITEs; continuous burst;

one bank active; address and control inputs changing once per

clock cycle; tCK = tCK (MIN); DQ, DM, and DQS inputs changing

twice per clock cycle

IDD4W 175 150 mA 22

AUTO REFRESH BURST CURRENT: tREFC =tRC (MIN) IDD5255 235 mA 49

tREFC = 7.8µs IDD5A 6 6 mA 27, 49

SELF REFRESH CURRENT: CKE ≤ 0.2V Standard IDD644mA11

Low power (L) IDD6A 22mA11

OPERATING CURRENT: Four-bank interleaving READs

(Burst = 4) with auto precharge, tRC = minimum tRC allowed;

tCK = tCK (MIN); address and control inputs change only during

active READ or WRITE commands

IDD7410 350 mA 22, 48

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Absolute Maximum Ratings

Table 22: IDD Specifications and Conditions (x4, x8; -75Z/-75)

0°C ≤ TA ≤ +70°C; VDDQ = +2.5V ±0.2V, VDD = +2.5V ±0.2V; Notes: 1–5, 10, 12, 14, 46; notes appear on

pages 69–74; See also Table 26, Idd Test Cycle Times, on page 64

Max

Parameter/Condition Symbol -75Z -75 Units Notes

OPERATING CURRENT: One bank; active precharge;

tRC = tRC (MIN); tCK = tCK (MIN); DQ, DM, and DQS inputs

changing once per clock cycle; address and control inputs changing

once every two clock cycles

IDD0120 120 mA 22, 47

OPERATING CURRENT: One bank; active-read precharge;

burst = 4; tRC = tRC (MIN); tCK = tCK (MIN); IOUT = 0mA; address

and control inputs changing once per clock cycle

IDD1145 145 mA 22, 47

PRECHARGE POWER-DOWN STANDBY CURRENT: All banks idle;

power-down mode; tCK = tCK (MIN); CKE = (LOW)

IDD2P 4 4 mA 23, 32, 49

IDLE STANDBY CURRENT: CS# = HIGH; all banks are idle;

tCK = tCK (MIN); CKE = HIGH; address and other control inputs

changing once per clock cycle; VIN = VREF for DQ, DQS, and DM

IDD2F 45 45 mA 50

ACTIVE POWER-DOWN STANDBY CURRENT: One bank active;

power-down mode; tCK = tCK (MIN); CKE = LOW

IDD3P 25 30 mA 23, 32, 49

ACTIVE STANDBY CURRENT: CS# = HIGH; CKE = HIGH;

one bank active; tRC = tRAS (MAX); tCK = tCK (MIN); DQ, DM, and

DQS inputs changing twice per clock cycle; address and other

control inputs changing once per clock cycle

IDD3N 50 50 mA 22

OPERATING CURRENT: Burst = 2; READs; continuous burst;

one bank active; address and control inputs changing once per

clock cycle; tCK = tCK (MIN); IOUT = 0mA

IDD4R 150 150 mA 22, 47

OPERATING CURRENT: Burst = 2; WRITEs; continuous burst;

one bank active; address and control inputs changing once per

clock cycle; tCK = tCK (MIN); DQ, DM, and DQS inputs changing

twice per clock cycle

IDD4W 150 150 mA 22

AUTO REFRESH BURST CURRENT: tREFC =tRC (MIN) IDD5235 245 mA 49

tREFC = 7.8µs IDD5A 6 6 mA 27, 49

SELF REFRESH CURRENT: CKE ≤ 0.2V Standard IDD644 mA 11

Low power (L) IDD6A 22 mA 11

OPERATING CURRENT: Four-bank interleaving READs

(Burst = 4) with auto precharge, tRC = minimum tRC allowed;

tCK = tCK (MIN); address and control inputs change only during

active READ or WRITE commands

IDD7350 365 mA 22, 48

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Absolute Maximum Ratings

Table 23: IDD Specifications and Conditions (x16; -5B)

0°C ≤ TA ≤ +70°C; (VDDQ = +2.6V ±0.1V, VDD = +2.6V ±0.1V); notes: 1–5, 10, 12, 14, 46; notes appear on

pages 69–74; See also Table 26, Idd Test Cycle Times, on page 64

Max

Parameter/Condition Symbol -5B Units Notes

OPERATING CURRENT: One bank; active precharge;

tRC = tRC (MIN); tCK = tCK (MIN); DQ, DM, and DQS inputs changing once

per clock cycle; address and control inputs changing once every two clock

cycles

IDD0135 mA 22, 47

OPERATING CURRENT: One bank; active-read precharge;

burst = 4; tRC = tRC (MIN); tCK = tCK (MIN); IOUT = 0mA; address and

control inputs changing once per clock cycle

IDD1185 mA 22, 47

PRECHARGE POWER-DOWN STANDBY CURRENT: All banks idle;

power-down mode; tCK = tCK (MIN); CKE = (LOW)

IDD2P 4 mA 23, 32, 49

IDLE STANDBY CURRENT: CS# = HIGH; all banks are idle;

tCK = tCK (MIN); CKE = HIGH; address and other control inputs changing

once per clock cycle; VIN = VREF for DQ, DQS, and DM

IDD2F 60 mA 50

ACTIVE POWER-DOWN STANDBY CURRENT: One bank active;

power-down mode; tCK = tCK (MIN); CKE = LOW

IDD3P 40 mA 23, 32, 49

ACTIVE STANDBY CURRENT: CS# = HIGH; CKE = HIGH;

one bank active; tRC = tRAS (MAX); tCK = tCK (MIN); DQ, DM, and DQS

inputs changing twice per clock cycle; address and other control inputs

changing once per clock cycle

IDD3N 70 mA 22

OPERATING CURRENT: Burst = 2; READs; continuous burst;

one bank active; address and control inputs changing once per clock cycle;

tCK = tCK (MIN); IOUT = 0mA

IDD4R 260 mA 22, 47

OPERATING CURRENT: Burst = 2; WRITEs; continuous burst;

one bank active; address and control inputs changing once per clock

cycle; tCK = tCK (MIN); DQ, DM, and DQS inputs changing twice per clock

cycle

IDD4W 215 mA 22

AUTO REFRESH BURST CURRENT: tREFC =tRC (MIN) IDD5260 mA 49

tREFC = 7.8µs IDD5A 6mA27, 49

SELF REFRESH CURRENT: CKE ≤ 0.2V Standard IDD64mA11

Low power (L) IDD6A 2mA11

OPERATING CURRENT: Four-bank interleaving READs

(Burst = 4) with auto precharge, tRC = minimum tRC allowed;

tCK = tCK (MIN); address and control inputs change only during active

READ or WRITE commands

IDD7510 mA 22, 48

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Absolute Maximum Ratings

Table 24: IDD Specifications and Conditions (x16; -6/-6T/-75E)

0°C ≤ TA ≤ +70°C; VDDQ = +2.5V ±0.2V, VDD = +2.5V ±0.2V; notes: 1–5, 10, 12, 14, 46; notes appear on

pages 69–74; See also Table 26, Idd Test Cycle Times, on page 64

Max

Parameter/Condition Symbol -6/6T -75E Units Notes

OPERATING CURRENT: One bank; active precharge;

tRC = tRC (MIN); tCK = tCK (MIN); DQ, DM, and DQS inputs changing

once per clock cycle; address and control inputs changing once every

two clock cycles

IDD0125 125 mA 22, 47

OPERATING CURRENT: One bank; active-read precharge;

burst = 4; tRC = tRC (MIN); tCK = tCK (MIN); IOUT = 0mA; address

and control inputs changing once per clock cycle

IDD1180 170 mA 22, 47

PRECHARGE POWER-DOWN STANDBY CURRENT: All banks idle;

power-down mode; tCK = tCK (MIN); CKE = (LOW)

IDD2P 4 4 mA 23, 32, 49

IDLE STANDBY CURRENT: CS# = HIGH; all banks are idle;

tCK = tCK (MIN); CKE = HIGH; address and other control inputs

changing once per clock cycle; VIN = VREF for DQ, DQS, and DM

IDD2F 50 45 mA 50

ACTIVE POWER-DOWN STANDBY CURRENT: One bank active;

power-down mode; tCK = tCK (MIN); CKE = LOW

IDD3P 30 25 mA 23, 32, 49

ACTIVE STANDBY CURRENT: CS# = HIGH; CKE = HIGH;

one bank active; tRC = tRAS (MAX); tCK = tCK (MIN); DQ, DM, and

DQS inputs changing twice per clock cycle; address and other control

inputs changing once per clock cycle

IDD3N 60 50 mA 22

OPERATING CURRENT: Burst = 2; READs; continuous burst;

one bank active; address and control inputs changing once per clock

cycle; tCK = tCK (MIN); IOUT = 0mA

IDD4R 220 185 mA 22, 47

OPERATING CURRENT: Burst = 2; WRITEs; continuous burst;

one bank active; address and control inputs changing once per clock

cycle; tCK = tCK (MIN); DQ, DM, and DQS inputs changing twice per

clock cycle

IDD4W 195 160 mA 22

AUTO REFRESH BURST CURRENT: tREFC =tRC (MIN) IDD5255 235 mA 49

tREFC = 7.8µs IDD5A 6 6 mA 27, 49

SELF REFRESH CURRENT: CKE ≤ 0.2V Standard IDD644mA11

Low power (L) IDD6A 22mA11

OPERATING CURRENT: Four-bank interleaving READs

(Burst = 4) with auto precharge, tRC = minimum tRC allowed;

tCK = tCK (MIN); address and control inputs change only during

active READ or WRITE commands

IDD7440 380 mA 22, 48

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Absolute Maximum Ratings

Table 25: IDD Specifications and Conditions (x16; -75Z/-75)

0°C ≤ TA ≤ +70°C; VDDQ = +2.5V ±0.2V, VDD = +2.5V ±0.2V

Notes: 1–5, 10, 12, 14, 46; notes appear on pages 69–74; See also Table 26, Idd Test Cycle Times, on page 64

MAX

Parameter/Condition Symbol -75Z -75 Units Notes

OPERATING CURRENT: One bank; active precharge;

tRC = tRC (MIN); tCK = tCK (MIN); DQ, DM, and DQS inputs changing

once per clock cycle; address and control inputs changing once every

two clock cycles

IDD0120 120 mA 22, 47

OPERATING CURRENT: One bank; active-read precharge;

burst = 4; tRC = tRC (MIN); tCK = tCK (MIN); IOUT = 0mA; address

and control inputs changing once per clock cycle

IDD1155 155 mA 22, 47

PRECHARGE POWER-DOWN STANDBY CURRENT: All banks idle;

power-down mode; tCK = tCK (MIN); CKE = (LOW)

IDD2P 4 4 mA 23, 32, 49

IDLE STANDBY CURRENT: CS# = HIGH; all banks are idle;

tCK = tCK (MIN); CKE = HIGH; address and other control inputs

changing once per clock cycle; VIN = VREF for DQ, DQS, and DM

IDD2F 45 45 mA 50

ACTIVE POWER-DOWN STANDBY CURRENT: One bank active;

power-down mode; tCK = tCK (MIN); CKE = LOW

IDD3P 25 30 mA 23, 32, 49

ACTIVE STANDBY CURRENT: CS# = HIGH; CKE = HIGH;

one bank active; tRC = tRAS (MAX); tCK = tCK (MIN); DQ, DM, and

DQS inputs changing twice per clock cycle; address and other control

inputs changing once per clock cycle

IDD3N 50 50 mA 22

OPERATING CURRENT: Burst = 2; READs; continuous burst;

one bank active; address and control inputs changing once per clock

cycle; tCK = tCK (MIN); IOUT = 0mA

IDD4R 185 185 mA 22, 47

OPERATING CURRENT: Burst = 2; WRITEs; continuous burst;

one bank active; address and control inputs changing once per clock

cycle; tCK = tCK (MIN); DQ, DM, and DQS inputs changing twice per

clock cycle

IDD4W 160 160 mA 22

AUTO REFRESH BURST CURRENT: tREFC =tRC(MIN) IDD5235 245 mA 49

tREFC = 7.8µs IDD5A 6 6 mA 27, 49

SELF REFRESH CURRENT: CKE ≤ 0.2V Standard IDD644mA 11

Low power (L) IDD6A 22mA 11

OPERATING CURRENT: Four-bank interleaving READs

(Burst = 4) with auto precharge, tRC = minimum tRC allowed;

tCK = tCK (MIN); address and control inputs change only during

active READ or WRITE commands

IDD7380 400 mA 22, 48

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Absolute Maximum Ratings

Table 26: IDD Test Cycle Times

Values reflect number of clock cycles for each test.

IDD Test

Speed

Grade

Clock Cycle

Time tRRD tRCD tRAS tRP tRC tRFC tREFI CL

IDD0-75/75Z 7.5ns NA NA 6 3 9 NA NA NA

-75E 7.5ns NA NA 6 2 8 NA NA NA

-6/-6T 6ns NA NA 7 3 10 NA NA NA

-5B 5ns NA NA 8 3 11 NA NA NA

IDD1-75 7.5ns NA NA 6 3 9 NA NA 2.5

-75Z 7.5ns NA NA 6 3 9 NA NA 2

-75E 7.5ns NA NA 6 2 8 NA NA 2

-6/-6T 6ns NA NA 7 3 10 NA NA 2.5

-5B 5ns NA NA NA NA NA NA NA 3

IDD4R -75 7.5ns NA NA NA NA NA NA NA 2.5

-75Z 7.5ns NA NA NA NA NA NA NA 2

-75E 7.5ns NA NA NA NA NA NA NA 2

-6/-6T 6ns NA NA NA NA NA NA NA 2.5

-5B 5ns NA NA NA NA NA NA NA 3

IDD4W -75 7.5ns NA NA NA NA NA NA NA NA

-75Z 7.5ns NA NA NA NA NA NA NA NA

-75E 7.5ns NA NA NA NA NA NA NA NA

-6/-6T 6ns NA NA NA NA NA NA NA NA

-5B 5ns NA NA NA NA NA NA NA NA

IDD5-75/75Z 7.5ns NA NA NA NA NA 10 10 NA

-75E 7.5ns NA NA NA NA NA 9 9 NA

-6/-6T 6ns NA NA NA NA NA 12 12 NA

-5B 5ns NA NA NA NA NA 14 14 NA

IDD5A -75/75Z 7.5ns NA NA NA NA NA 10 1,030 NA

-75E 7.5ns NA NA NA NA NA 9 1,030 NA

-6/-6T 6ns NA NA NA NA NA 12 1,288 NA

-5B 5ns NA NA NA NA NA 14 1,546 NA

IDD7-75 7.5ns 2/4 3 NA 3 10 NA NA 2.5

-75Z 7.5ns 2/4 3 NA 3 10 NA NA 2

-75E 7.5ns 2 3 NA 2 8 NA NA 2

-6/-6T 6ns 2/4 3 NA 3 10 NA NA 2.5

-5B 5ns 2/4 3 NA 3 11 NA NA 3

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Absolute Maximum Ratings

Table 27: Electrical Characteristics and Recommended AC Operating Conditions (-5B)

Notes: 1–5, 14–17, 33; notes on pages 69–74; 0°C ≤ TA ≤ +70°C; (VDDQ = +2.6V ±0.1V, VDD = +2.6V ±0.1V)

AC Characteristics -5B

Parameter Symbol Min Max Units Notes

Access window of DQs from CK/CK# tAC -0.70 +0.70 ns

CK high-level width tCH 0.45 0.55 tCK 30

CK low-level width tCL 0.45 0.55 tCK 30

Clock cycle time CL = 3 tCK (3) 5 7.5 ns 51

CL = 2.5 tCK (2.5) 6 13 ns 45, 51

CL = 2 tCK (2) 7.5 13 ns 45, 51

DQ and DM input hold time relative to DQS tDH 0.40 ns 26, 31

DQ and DM input setup time relative to DQS tDS 0.40 ns 26, 31

DQ and DM input pulse width (for each input) tDIPW 1.75 ns 31

Access window of DQS from CK/CK# tDQSCK -0.6 +0.6 ns

DQS input high pulse width tDQSH 0.35 tCK

DQS input low pulse width tDQSL 0.35 tCK

DQS–DQ skew, DQS to last DQ valid, per group, per access

tDQSQ 0.4 ns 25, 26

WRITE command to first DQS latching transition tDQSS 0.72 1.28 tCK

DQS falling edge to CK rising – setup time tDSS 0.2 tCK

DQS falling edge from CK rising – hold time tDSH 0.2 tCK

Half clock period tHP tCH,tCL ns 34

Data-out high-impedance window from CK/CK# tHZ +0.7 ns 18, 42

Data-out low-impedance window from CK/CK# tLZ -0.7 ns 18, 42

Address and control input hold time (fast slew rate) tIHF0.60 ns

Address and control input setup time (fast slew rate) tISF0.60 ns

Address and control input hold time (slow slew rate) tIHS0.60 ns 14

Address and control input setup time (slow slew rate) tISS0.60 ns 14

Address and Control input pulse width (for each input) tIPW 2.2 ns

LOAD MODE REGISTER command cycle time tMRD 10 ns

DQ–DQS hold, DQS to first DQ to go non-valid, per access tQH tHP

-tQHS

ns 25, 26

Data hold skew factor tQHS 0.5 ns

ACTIVE to PRECHARGE command tRAS 40 70,000 ns 35

ACTIVE to READ with auto precharge command tRAP 15 ns

ACTIVE to ACTIVE/AUTO REFRESH command period tRC 55 ns

AUTO REFRESH command period tRFC 70 ns 49

ACTIVE to READ or WRITE delay tRCD 15 ns

PRECHARGE command period tRP 15 ns

DQS read preamble tRPRE 0.9 1.1 tCK 43

DQS read postamble tRPST 0.4 0.6 tCK 43

ACTIVE bank a to ACTIVE bank b command tRRD 10 ns

DQS write preamble tWPRE 0.25 tCK

DQS write preamble setup time tWPRES 0 ns 20, 21

DQS write postamble tWPST 0.4 0.6 tCK 19

Write recovery time tWR 15 ns

Internal WRITE to READ command delay tWTR 2 tCK

Data valid output window (DVW) N/A tQH - tDQSQ ns 25

REFRESH to REFRESH command interval tREFC 70.3 µs 23

Average periodic refresh interval tREFI 7.8 µs 23

Terminating voltage delay to VDD tVTD 0 ns

Exit SELF REFRESH to non-READ command tXSNR 70 ns

Exit SELF REFRESH to READ command tXSRD 200 tCK

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Absolute Maximum Ratings

Table 28: Electrical Characteristics and Recommended AC Operating Conditions (-6/-6T/-75E)

Notes: 1–5, 14–17, 33; notes appear on pages 69–74; 0°C ≤ TA ≤ +70°C; VDDQ = +2.5V ±0.2V, VDD = +2.5V ±0.2V

AC Characteristics -6 (FBGA) -6T (TSOP) -75E

Parameter Symbol Min Max Min Max Min Max Units Notes

Access window of DQs from CK/CK# tAC -0.70 +0.70 -0.70 +0.70 -0.75 +0.75 ns

CK high-level width tCH 0.45 0.55 0.45 0.55 0.45 0.55 tCK 30

CK low-level width tCL 0.45 0.55 0.45 0.55 0.45 0.55 tCK 30

Clock cycle time CL = 2.5 tCK (2.5) 6 13 6 13 7.5 13 ns 45, 51

CL = 2 tCK (2) 7.5 13 7.5 13 7.5 13 ns 45, 51

DQ and DM input hold time relative to DQS tDH 0.45 0.45 0.5 ns 26, 31

DQ and DM input setup time relative to DQS tDS 0.45 0.45 0.5 ns 26, 31

DQ and DM input pulse width (for each input) tDIPW 1.75 1.75 1.75 ns 31

Access window of DQS from CK/CK# tDQSCK -0.6 +0.6 -0.6 +0.6 -0.75 +0.75 ns

DQS input high pulse width tDQSH 0.35 0.35 0.35 tCK

DQS input low pulse width tDQSL 0.35 0.35 0.35 tCK

DQS–DQ skew, DQS to last DQ valid, per group, per access

tDQSQ 0.4 0.45 0.5 ns 25, 26

WRITE command to first DQS latching transition tDQSS 0.75 1.25 0.75 1.25 0.75 1.25 tCK

DQS falling edge to CK rising – setup time tDSS 0.2 0.2 0.2 tCK

DQS falling edge from CK rising – hold time tDSH 0.2 0.2 0.2 tCK

Half clock period tHP tCH,tCL tCH,tCL tCH,tCL ns 34

Data-out high-impedance window from CK/CK# tHZ +0.7 +0.7 +0.75 ns 18, 42

Data-out low-impedance window from CK/CK# tLZ -0.7 -0.7 -0.75 ns 18, 42

Address and control input hold time (fast slew rate) tIHF0.75 0.75 0.90 ns

Address and control input setup time (fast slew rate) tISF0.75 0.75 0.90 ns

Address and control input hold time (slow slew rate) tIHS0.8 0.8 1 ns 14

Address and control input setup time (slow slew rate) tISS0.8 0.8 1 ns 14

Address and Control input pulse width (for each input) tIPW 2.2 2.2 2.2 ns

LOAD MODE REGISTER command cycle time tMRD 12 12 15 ns

DQ–DQS hold, DQS to first DQ to go non-valid, per access tQH tHP

-tQHS

tHP

-tQHS

tHP

-tQHS

ns 25, 26

Data hold skew factor tQHS 0.5 0.55 0.75 ns

ACTIVE to PRECHARGE command tRAS 42 70,000 42 70,000 40 120,000 ns 35, 53

ACTIVE to READ with auto precharge command tRAP 15 15 15 ns

ACTIVE to ACTIVE/AUTO REFRESH command period tRC 60 60 60 ns

AUTO REFRESH command period tRFC 72 72 75 ns 49

ACTIVE to READ or WRITE delay tRCD 15 15 15 ns

PRECHARGE command period tRP 15 15 15 ns

DQS read preamble tRPRE 0.9 1.1 0.9 1.1 0.9 1.1 tCK 43

DQS read postamble tRPST 0.4 0.6 0.4 0.6 0.4 0.6 tCK 43

ACTIVE bank a to ACTIVE bank b command tRRD 12 12 15 ns

DQS write preamble tWPRE 0.25 0.25 0.25 tCK

DQS write preamble setup time tWPRES 0 0 0 ns 20, 21

DQS write postamble tWPST 0.4 0.6 0.4 0.6 0.4 0.6 tCK 19

Write recovery time tWR 15 15 15 ns

Internal WRITE to READ command delay tWTR 1 1 1 tCK

Data valid output window (DVW) N/A tQH - tDQSQ tQH - tDQSQ tQH - tDQSQ ns 25

REFRESH to REFRESH command interval tREFC 70.3 70.3 70.3 µs 23

Average periodic refresh interval tREFI 7.8 7.8 7.8 µs 23

Terminating voltage delay to VDD tVTD 0 0 0 ns

Exit SELF REFRESH to non-READ command tXSNR 75 75 75 ns

Exit SELF REFRESH to READ command tXSRD 200 200 200 tCK

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Absolute Maximum Ratings

Table 29: Electrical Characteristics and Recommended AC Operating Conditions (-75Z/-75)

Notes: 1–5, 14–17, 33; notes appear on pages 69–74; 0°C ≤ TA ≤ +70°C; VDDQ = +2.5V ±0.2V, VDD = +2.5V ±0.2V

AC Characteristics -75Z -75

Parameter Symbol Min Max Min Max Units Notes

Access window of DQs from CK/CK# tAC -0.75 +0.75 -0.75 +0.75 ns

CK high-level width tCH 0.45 0.55 0.45 0.55 tCK 30

CK low-level width tCL 0.45 0.55 0.45 0.55 tCK 30

Clock cycle time CL=2.5 tCK (2.5) 7.5 13 7.5 13 ns 45, 51

CL=2 tCK (2) 7.5 13 10 13 ns 45, 51

DQ and DM input hold time relative to DQS tDH 0.50 0.50 ns 26, 31

DQ and DM input setup time relative to DQS tDS 0.50 0.50 ns 26, 31

DQ and DM input pulse width (for each input) tDIPW 1.75 1.75 ns 31

Access window of DQS from CK/CK# tDQSCK -0.75 +0.75 -0.75 +0.75 ns

DQS input high pulse width tDQSH 0.35 0.35 tCK

DQS input low pulse width tDQSL 0.35 0.35 tCK

DQS–DQ skew, DQS to last DQ valid, per group, per access

tDQSQ 0.5 0.5 ns 25, 26

WRITE command to first DQS latching transition tDQSS 0.75 1.25 0.75 1.25 tCK

DQS falling edge to CK rising – setup time tDSS 0.20 0.20 tCK

DQS falling edge from CK rising – hold time tDSH 0.20 0.20 tCK

Half clock period tHP tCH,tCL tCH,tCL ns 34

Data-out high-impedance window from CK/CK# tHZ +0.75 +0.75 ns 18, 42

Data-out low-impedance window from CK/CK# tLZ -0.75 -0.75 ns 18, 42

Address and control input hold time (fast slew rate) tIHF0.90 0.90 ns

Address and control input setup time (fast slew rate) tISF0.90 0.90 ns

Address and control input hold time (slow slew rate) tIHS11 ns14

Address and control input setup time (slow slew rate) tISS11 ns14

Address and Control input pulse width (for each input) tIPW 2.2 2.2 ns

LOAD MODE REGISTER command cycle time tMRD 15 15 ns

DQ–DQS hold, DQS to first DQ to go non-valid, per access tQH tHP

-tQHS

tHP

-tQHS

ns 25, 26

Data hold skew factor tQHS 0.75 0.75 ns

ACTIVE to PRECHARGE command tRAS 40 120,000 40 120,000 ns 35

ACTIVE to READ with auto precharge command tRAP 20 20 ns

ACTIVE to ACTIVE/AUTO REFRESH command period tRC 65 65 ns

AUTO REFRESH command period tRFC 75 75 ns 49

ACTIVE to READ or WRITE delay tRCD 20 20 ns

PRECHARGE command period tRP 20 20 ns

DQS read preamble tRPRE 0.9 1.1 0.9 1.1 tCK 43

DQS read postamble tRPST 0.4 0.6 0.4 0.6 tCK 43

ACTIVE bank a to ACTIVE bank b command tRRD 15 15 ns

DQS write preamble tWPRE 0.25 0.25 tCK

DQS write preamble setup time tWPRES 0 0 ns 20, 21

DQS write postamble tWPST 0.4 0.6 0.4 0.6 tCK 19

Write recovery time tWR 15 15 ns

Internal WRITE to READ command delay tWTR 1 1 tCK

Data valid output window (DVW) N/A tQH - tDQSQ tQH - tDQSQ ns 25

REFRESH to REFRESH command interval tREFC 70.3 70.3 µs 23

Average periodic refresh interval tREFI 7.8 7.8 µs 23

Terminating voltage delay to VDD tVTD 0 0 ns

Exit SELF REFRESH to non-READ command tXSNR 75 75 ns

Exit SELF REFRESH to READ command tXSRD 200 200 tCK

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Absolute Maximum Ratings

Table 30: Input Slew Rate Derating Values for Addresses and Commands

0°C ≤ TA ≤ +70°C; VDDQ = +2.5V ±0.2V, VDD = +2.5V ±0.2V; notes: 14; notes appear on pages 69–74

SPEED SLEW RATE tIS tIH UNITS

-75/-75Z/-75E 0.50 V/ns ≤ Slew Rate < 1.0 V/ns 1.00 1 ns

-75/-75Z/-75E 0.40 V/ns ≤ Slew Rate < 0.5 V/ns 1.05 1 ns

-75/-75Z/-75E 0.30 V/ns ≤ Slew Rate < 0.4 V/ns 1.15 1 ns

Table 31: Input Slew Rate Derating Values for DQ, DQS, and DM

0°C ≤ TA ≤ +70°C; VDDQ = +2.5V ±0.2V, VDD = +2.5V ±0.2V; notes: 31; notes appear on pages 69-74

SPEED SLEW RATE tDS tDH UNITS

-75/-75Z/-75E 0.50 V/ns ≤ Slew Rate < 1.0 V/ns 0.50 0.50 ns

-75/-75Z/-75E 0.40 V/ns ≤ Slew Rate < 0.5 V/ns 0.55 0.55 ns

-75/-75Z/-75E 0.30 V/ns ≤ Slew Rate < 0.4 V/ns 0.60 0.60 ns

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Notes

1. All voltages referenced to VSS.

2. Tests for AC timing, IDD, and electrical AC and DC characteristics may be conducted

at nominal reference/supply voltage levels, but the related specifications and device

operation are guaranteed for the full voltage range specified.

3. Outputs (except for IDD measurements) measured with equivalent load:

4. AC timing and IDD tests may use a VIL-to-VIH swing of up to 1.5V in the test environ-

ment, but input timing is still referenced to VREF (or to the crossing point for CK/CK#),

and parameter specifications are guaranteed for the specified AC input levels under

normal use conditions. The minimum slew rate for the input signals used to test the

device is 1 V/ns in the range between VIL(AC) and VIH(AC).

5. The AC and DC input level specifications are as defined in the SSTL_2 standard (i.e.,

the receiver will effectively switch as a result of the signal crossing the AC input level

and will remain in that state as long as the signal does not ring back above [below] the

DC input LOW [HIGH] level).

6. VREF is expected to equal VDDQ/2 of the transmitting device and to track variations in

the DC level of the same. Peak-to-peak noise (noncommon mode) on VREF may not

exceed ±2 percent of the DC value. Thus, from VDDQ/2, VREF is allowed ±25mV for DC

error and an additional ±25mV for AC noise. This measurement is to be taken at the

nearest VREF bypass capacitor.

7. VTT is not applied directly to the device. VTT, a system supply for signal termination

resistors, is expected to be set equal to VREF and must track variations in the DC level

of VREF.

8. VID is the magnitude of the difference between the input level on CK and the input

level on CK#.

9. The value of VIX and VMP are expected to equal VDDQ/2 of the transmitting device and

must track variations in the DC level of the same.

10. IDD is dependent on output loading and cycle rates. Specified values are obtained

with minimum cycle times at CL=3 for -5B, CL = 2.5 for -6/-6T and -75, and CL = 2 for

-75E/-75Z speeds with the outputs open.

11. Enables on-chip refresh and address counters.

12. IDD specifications are tested after the device is properly initialized and is averaged at

the defined cycle rate.

13. This parameter is sampled. VDD = +2.5V±0.2V, VDDQ = +2.5V±0.2V, VREF = VSS, f = 100

MHz, TA = 25°C, VOUT (DC) = VDDQ/2, VOUT (peak to peak) = 0.2V. DM input is

grouped with I/O pins, reflecting that they are matched in loading.

14. For slew rates < 1 V/ns and ≥ 0.5 V/ns. If slew rate is less than 0.5 V/ns, timing must be

derated; tIS has an additional 50ps per each 100mV/ns reduction in slew rate from the

500mV/ns, while tIH is unaffected. If the slew rate exceeds 4.5 V/ns, functionality is

uncertain. For -5B, -6 and -6T, slew rates must be greater than or equal to 0.5V/ns.

15. The CK/CK# input reference level (for timing referenced to CK/CK#) is the point at

which CK and CK# cross; the input reference level for signals other than CK/CK# is

VREF.

Output

(VOUT)

Reference

Point

50Ω

VTT

30pF

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Notes

16. Inputs are not recognized as valid until VREF stabilizes. Once initialized, including

Self-Refresh mode, VREF must be powered within the specified range. Exception: dur-

ing the period before VREF stabilizes, CKE = 0.3 x VDDQ is recognized as LOW.

17. The output timing reference level, as measured at the timing reference point indi-

cated in Note 3, is VTT.

18. tHZ and tLZ transitions occur in the same access time windows as data valid transi-

tions. These parameters are not referenced to a specific voltage level, but specify

when the device output is no longer driving (HZ) or begins driving (LZ).

19. The intent of the “Don’t Care” state after completion of the postamble is that the DQS-

driven signal should either be HIGH, LOW, or High-Z and that any signal transition

within the input switching region must follow valid input requirements. If DQS transi-

tions HIGH, above DC VIH (MIN) then it must not transition LOW, below DC VIH, prior

to tDQSH (MIN).

20. This is not a device limit. The device will operate with a negative value, but system

performance could be degraded due to bus turnaround.

21. It is recommended that DQS be valid (HIGH or LOW) on or before the WRITE com-

mand. The case shown (DQS going from High-Z to logic LOW) applies when no

WRITEs were previously in progress on the bus. If a previous WRITE was in progress,

DQS could be HIGH during this time, depending on tDQSS.

22. tRC (MIN) or tRFC (MIN) for IDD measurements is the smallest multiple of tCK

that meets the minimum absolute value for the respective parameter. tRAS (MAX)

for IDD measurements is the largest multiple of tCK that meets the maximum

absolute value for tRAS.

23. The refresh period is 64ms. This equates to an average refresh rate of 7.8125µs. How-

ever, an AUTO REFRESH command must be asserted at least once every 70.3µs; burst

refreshing or posting by the DRAM controller greater than eight refresh cycles is not

allowed.

24. The I/O capacitance per DQS and DQ byte/group will not differ by more than this

maximum amount for any given device.

25. The data valid window is derived by achieving other specifications: tHP (tCK/2),

tDQSQ, and tQH (tQH = tHP - tQHS). The data valid window derates in direct pro-

portion to the clock duty cycle and a practical data valid window can be derived.

The clock is allowed a maximum duty-cycle variation of 45/55, because function-

ality is uncertain when operating beyond a 45/55 ratio. Figure 35 on page 71

shows data valid window derating curves for duty cycles ranging between 50/50

and 45/55.

26. Referenced to each output group: x4 = DQS with DQ0–DQ3; x8 = DQS with DQ0–DQ7;

x16 = LDQS with DQ0–DQ7; and UDQS with DQ8–DQ15.

27. This limit is actually a nominal value and does not result in a fail value. CKE is HIGH

during REFRESH command period (tRFC [MIN]) else CKE is LOW (i.e., during

standby).

28. To maintain a valid level, the transitioning edge of the input must:

a. Sustain a constant slew rate from the current AC level through to the target AC

level, VIL (AC) or VIH (AC).

b. Reach at least the target AC level.

c. After the AC target level is reached, continue to maintain at least the target DC

level, VIL (DC) or VIH (DC).

29. The Input capacitance per pin group will not differ by more than this maximum

amount for any given device.

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Notes

Figure 35: Derating Data Valid Window (tQH - tDQSQ)

Examples are for speed grades through -75

30. CK and CK# input slew rate must be ≥ 1V/ns (≥2V/ns if measured differentially).

31. DQ and DM input slew rates must not deviate from DQS by more than 10 percent. If

the DQ/DM/DQS slew rate is less than 0.5 V/ns, timing must be derated: 50ps must be

added to tDS and tDH for each 0.1 V/ns reduction in slew rate. For -5B, -6 and -6T

speed grades, slew rate must be ≥0.5 V/ns. If slew rate exceeds 4 V/ns, functionality is

uncertain.

32. VDD must not vary more than four percent if CKE is not active while any bank is

active.

33. The clock is allowed up to ±150ps of jitter. Each timing parameter is allowed to vary by

the same amount.

34. tHP (MIN) is the lesser of tCL minimum and tCH minimum actually applied to the

device CK and CK# inputs, collectively during bank active.

35. READs and WRITEs with auto precharge are not allowed to be issued until tRAS (MIN)

can be satisfied prior to the internal PRECHARGE command being issued.

36. Any positive glitch must be less than 1/3 of the clock cycle and not more than +400mV

or 2.9V (+300mV or 2.9V maximum for -5B), whichever is less. Any negative glitch

must be less than 1/3 of the clock cycle and not exceed either -300mV or 2.2V, (2.4V for

-5B) whichever is more positive. The average cannot be below the +2.5V (2.6V for -5B)

minimum.

3.750 3.700 3.650 3.600

3.550

3.500 3.450

3.400 3.350 3.300

3.250

3.400 3.350 3.300

3.250

3.200 3.150

3.100 3.050

3.000 2.950 2.900

2.500 2.463 2.425 2.388 2.350 2.313 2.275 2.238 2.200 2.163 2.125

1.8

2.0

2.2

2.4

2.6

2.8

3.0

3.2

3.4

3.6

3.8

50/50 49.5/50.5 49/51 48.5/52.5 48/52 47.5/53.5 47/53 46.5/54.5 46/54 45.5/55.5 45/55

Clock Du ty C yc le

—— -75 @ tCK = 10ns

—— -8 @ tCK = 10ns

—— -75 @ tCK = 7.5ns

—— -8 @ tCK = 8ns

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Notes

37. Normal output drive curves:

a. The full variation in driver pull-down current from minimum to maximum pro-

cess, temperature, and voltage will lie within the outer bounding lines of the V-I

curve of Figure 36

b. The variation in driver pull-down current within nominal limits of voltage and

temperature is expected, but not guaranteed, to lie within the inner bounding

lines of the V-I curve of Figure 36.

c. The full variation in driver pull-up current from minimum to maximum process,

temperature and voltage will lie within the outer bounding lines of the V-I curve of

Figure 37.

d. The variation in driver pull-up current within nominal limits of voltage and tem-

perature is expected, but not guaranteed, to lie within the inner bounding lines of

the V-I curve of Figure 37.

e. The full variation in the ratio of the maximum to minimum pull-up and pull-down

current should be between 0.71 and 1.4, for device drain-to-source voltages from

0.1V to 1.0V, and at the same voltage and temperature. f) The full variation in the

ratio of the nominal pull-up to pull-down current should be unity ±10 percent, for

device drain-to-source voltages from 0.1V to 1.0V.

Figure 36: Full Drive Pull-Down Characteristics

Figure 37: Full Drive Pull-Up Characteristics

100

120

140

160

0.0 0.5 1.0 1.5 2.0 2.5

VOUT (V)

OUT

(mA)

-200

-180

-160

-140

-120

-100

-80

-60

-40

-20

0.0 0.5 1.0 1.5 2.0 2.5

VDDQ - V OUT (V )

OUT

(m A)

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Notes

38. Reduced output drive curves:

a. The full variation in driver pull-down current from minimum to maximum pro-

cess, temperature, and voltage will lie within the outer bounding lines of the V-I

curve of Figure 38.

b. The variation in driver pull-down current within nominal limits of voltage and

temperature is expected, but not guaranteed, to lie within the inner bounding

lines of the V-I curve of Figure 38.

c. The full variation in driver pull-up current from minimum to maximum process,

temperature and voltage will lie within the outer bounding lines of the V-I curve of

Figure 39.

d. The variation in driver pull-up current within nominal limits of voltage and tem-

perature is expected, but not guaranteed, to lie within the inner bounding lines of

the V-I curve of Figure 39.

e. The full variation in the ratio of the maximum to minimum pull-up and pull-down

current should be between 0.71 and 1.4 for device drain-to-source voltages from

0.1V to 1.0V, and at the same voltage and temperature.

f. The full variation in the ratio of the nominal pull-up to pull-down current should

be unity ±10 percent, for device drain-to-source voltages from 0.1V to 1.0V.

Figure 38: Reduced Drive Pull-Down Characteristics

Figure 39: Reduced Drive Pull-Up Characteristics

0.00.51.01.52.

VOUT (V)

OUT

(mA)

-80

-70

-60

-50

-40

-30

-20

-10

0.0 0.5 1.0 1.5 2.0 2.5

VDDQ - VOUT (V)

OUT

(mA)

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Notes

39. The voltage levels used are derived from a minimum VDD level and the referenced

test load. In practice, the voltage levels obtained from a properly terminated bus

will provide significantly different voltage values.

40. VIH overshoot: VIH (MAX) = VDDQ + 1.5V for a pulse width ≤ 3ns and the pulse

width can not be greater than 1/3 of the cycle rate. VIL undershoot: VIL (MIN) = -

1.5V for a pulse width ≤ 3ns and the pulse width can not be greater than 1/3 of the

cycle rate.

41. VDD and VDDQ must track each other.

42. tHZ (MAX) will prevail over tDQSCK (MAX) + tRPST (MAX) condition. tLZ (MIN) will

prevail over tDQSCK (MIN) + tRPRE (MAX) condition.

43. tRPST end point and tRPRE begin point are not referenced to a specific voltage level

but specify when the device output is no longer driving (tRPST), or begins driving

(tRPRE).

44. During initialization, VDDQ, VTT, and VREF must be equal to or less than VDD + 0.3V.

Alternatively, VTT may be 1.35V maximum during power-up, even if VDD/VDDQ are 0V,

provided a minimum of 42Ω of series resistance is used between the VTT supply and

the input pin.

45. The current Micron part operates below the slowest JEDEC operating frequency of 83

MHz. As such, future die may not reflect this option.

46. When an input signal is indicated to be HIGH or LOW, it is defined as a steady state

logic HIGH or LOW.

47. Random addressing changing; 50 percent of data changing at every transfer.

48. Random addressing changing; 100 percent of data changing at every transfer.

49. CKE must be active (HIGH) during the entire time a refresh command is executed.

That is, from the time the AUTO REFRESH command is registered, CKE must be

active at each rising clock edge, until tRFC has been satisfied.

50. IDD2N specifies the DQ, DQS and DM to be driven to a valid HIGH or LOW logic level.

IDD2Q is similar to IDD2F except IDD2Q specifies the address and control inputs to

remain stable. Although IDD2F, IDD2N, and IDD2Q are similar, IDD2F is “worst case.”

51. Whenever the operating frequency is altered, not including jitter, the DLL is required

to be reset followed by 200 clock cycles before any READ command.

52. This is the DC voltage supplied at the DRAM and is inclusive of all noise up to 20 MHz.

Any noise above 20 MHz at the DRAM generated from any source other than that of

the DRAM itself may not exceed the DC voltage range of 2.6V±100mV.

53. The -6/-6T speed grades will operate with tRAS(min) = 40ns and tRAS(max) =

120,000ns at any slower frequency.

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Output Drive Characteristics

Note: The above characteristics are specified under best, worst, and nominal process variations/

conditions.

Table 32: Normal Output Drive Characteristics

Voltage

(V)

Pull-Down CurrenT (mA) Pull-Up Current (mA)

Nominal

Low

Nominal

High Minimum Maximum

Nominal

Low

Nominal

High Minimum Maximum

0.1 6.0 6.8 4.6 9.6 -6.1 -7.6 -4.6 -10.0

0.2 12.2 13.5 9.2 18.2 -12.2 -14.5 -9.2 -20.0

0.3 18.1 20.1 13.8 26.0 -18.1 -21.2 -13.8 -29.8

0.4 24.1 26.6 18.4 33.9 -24.0 -27.7 -18.4 -38.8

0.5 29.8 33.0 23.0 41.8 -29.8 -34.1 -23.0 -46.8

0.6 34.6 39.1 27.7 49.4 -34.3 -40.5 -27.7 -54.4

0.7 39.4 44.2 32.2 56.8 -38.1 -46.9 -32.2 -61.8

0.8 43.7 49.8 36.8 63.2 -41.1 -53.1 -36.0 -69.5

0.9 47.5 55.2 39.6 69.9 -43.8 -59.4 -38.2 -77.3

1.0 51.3 60.3 42.6 76.3 -46.0 -65.5 -38.7 -85.2

1.1 54.1 65.2 44.8 82.5 -47.8 -71.6 -39.0 -93.0

1.2 56.2 69.9 46.2 88.3 -49.2 -77.6 -39.2 -100.6

1.3 57.9 74.2 47.1 93.8 -50.0 -83.6 -39.4 -108.1

1.4 59.3 78.4 47.4 99.1 -50.5 -89.7 -39.6 -115.5

1.5 60.1 82.3 47.7 103.8 -50.7 -95.5 -39.9 -123.0

1.6 60.5 85.9 48.0 108.4 -51.0 -101.3 -40.1 -130.4

1.7 61.0 89.1 48.4 112.1 -51.1 -107.1 -40.2 -136.7

1.8 61.5 92.2 48.9 115.9 -51.3 -112.4 -40.3 -144.2

1.9 62.0 95.3 49.1 119.6 -51.5 -118.7 -40.4 -150.5

2.0 62.5 97.2 49.4 123.3 -51.6 -124.0 -40.5 -156.9

2.1 62.8 99.1 49.6 126.5 -51.8 -129.3 -40.6 -163.2

2.2 63.3 100.9 49.8 129.5 -52.0 -134.6 -40.7 -169.6

2.3 63.8 101.9 49.9 132.4 -52.2 -139.9 -40.8 -176.0

2.4 64.1 102.8 50.0 135.0 -52.3 -145.2 -40.9 -181.3

2.5 64.6 103.8 50.2 137.3 -52.5 -150.5 -41.0 -187.6

2.6 64.8 104.6 50.4 139.2 -52.7 -155.3 -41.1 -192.9

2.7 65.0 105.4 50.5 140.8 -52.8 -160.1 -41.2 -198.2

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Output Drive Characteristics

Note: The above characteristics are specified under best, worst, and nominal process variations/

conditions.

Table 33: Reduced Output Drive Characteristics

Voltage

(V)

Pull-Down CurrenT (mA) Pull-Up Current (mA)

Nominal

Low

Nominal

High Minimum Maximum

Nominal

Low

Nominal

High Minimum Maximum

0.1 3.4 3.8 2.6 5.0 -3.5 -4.3 -2.6 -5.0

0.2 6.9 7.6 5.2 9.9 -6.9 -7.8 -5.2 -9.9

0.3 10.3 11.4 7.8 14.6 -10.3 -12.0 -7.8 -14.6

0.4 13.6 15.1 10.4 19.2 -13.6 -15.7 -10.4 -19.2

0.5 16.9 18.7 13.0 23.6 -16.9 -19.3 -13.0 -23.6

0.6 19.9 22.1 15.7 28.0 -19.4 -22.9 -15.7 -28.0

0.7 22.3 25.0 18.2 32.2 -21.5 -26.5 -18.2 -32.2

0.8 24.7 28.2 20.8 35.8 -23.3 -30.1 -20.4 -35.8

0.9 26.9 31.3 22.4 39.5 -24.8 -33.6 -21.6 -39.5

1.0 29.0 34.1 24.1 43.2 -26.0 -37.1 -21.9 -43.2

1.1 30.6 36.9 25.4 46.7 -27.1 -40.3 -22.1 -46.7

1.2 31.8 39.5 26.2 50.0 -27.8 -43.1 -22.2 -50.0

1.3 32.8 42.0 26.6 53.1 -28.3 -45.8 -22.3 -53.1

1.4 33.5 44.4 26.8 56.1 -28.6 -48.4 -22.4 -56.1

1.5 34.0 46.6 27.0 58.7 -28.7 -50.7 -22.6 -58.7

1.6 34.3 48.6 27.2 61.4 -28.9 -52.9 -22.7 -61.4

1.7 34.5 50.5 27.4 63.5 -28.9 -55.0 -22.7 -63.5

1.8 34.8 52.2 27.7 65.6 -29.0 -56.8 -22.8 -65.6

1.9 35.1 53.9 27.8 67.7 -29.2 -58.7 -22.9 -67.7

2.0 35.4 55.0 28.0 69.8 -29.2 -60.0 -22.9 -69.8

2.1 35.6 56.1 28.1 71.6 -29.3 -61.2 -23.0 -71.6

2.2 35.8 57.1 28.2 73.3 -29.5 -62.4 -23.0 -73.3

2.3 36.1 57.7 28.3 74.9 -29.5 -63.1 -23.1 -74.9

2.4 36.3 58.2 28.3 76.4 -29.6 -63.8 -23.2 -76.4

2.5 36.5 58.7 28.4 77.7 -29.7 -64.4 -23.2 -77.7

2.6 36.7 59.2 28.5 78.8 -29.8 -65.1 -23.3 -78.8

2.7 36.8 59.6 28.6 79.7 -29.9 -65.8 -23.3 -79.7

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Data Output Timing Diagrams

Figure 40: x4, x8 Data Output Timing – tDQSQ, tQH, and Data Valid Window

Notes: 1. DQ transitioning after DQS transition define tDQSQ window. DQS transitions at T2 and at

T2n are “early DQS,” at T3, “nominal DQS,” and at T3n, “late DQS.”

2. For a x4, only two DQ apply.

3. tDQSQ is derived at each DQS clock edge and is not cumulative over time and begins with

DQS transition and ends with the last valid DQ transition.

4. tQH is derived from tHP: tQH = tHP - tQHS.

5. tHP is the lesser of tCL or tCH clock transition collectively when a bank is active.

6. The data valid window is derived for each DQS transitions and is defined as tQH minus

tDQSQ.

DQ (Last data valid)

DQS

DQ (Last data valid)

DQ (First data no longer valid)

All DQ and DQS, collectively

Earliest signal transition

Latest signal transition

T2n

T3n

CK#

T1 T2 T3 T4T2n T3n

tQH

tHP

tQH

tHP

tQH

tDQSQ

Data

Valid

window

Data

Valid

window

Data

Valid

window

Data

Valid

window

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Data Output Timing Diagrams

Figure 41: x16 Data Output Timing – tDQSQ, tQH, and Data Valid Window

Notes: 1. DQ transitioning after DQS transition define tDQSQ window. LDQS defines the lower byte

and UDQS defines the upper byte.

2. DQ0, DQ1, DQ2, DQ3, DQ4, DQ5, DQ6, or DQ7.

3. tDQSQ is derived at each DQS clock edge and is not cumulative over time and begins with

DQS transition and ends with the last valid DQ transition.

4. tQH is derived from tHP: tQH = tHP - tQHS.

5. tHP is the lesser of tCL or tCH clock transition collectively when a bank is active.

6. The data valid window is derived for each DQS transition and is tQH minus tDQSQ.

7. DQ8, DQ9, DQ10, D11, DQ12, DQ13, DQ14, or DQ15.

DQ (Last data valid)

LDQS

DQ (Last data valid)

DQ (First data no longer valid)

DQ0 - DQ7 and LDQS, collectively

T2n

T3n

CK#

T1 T2 T3 T4T2n T3n

tQH

tDQSQ

Data Valid

window

Data Valid

window

DQ (Last data valid)

UDQS

DQ (Last data valid)

DQ (First data no longer valid)

DQ8 - DQ15 and UDQS, collectively

T2n

T3n

tQH

tDQSQ

tHP

tQH

Data Valid

window

Data Valid

window Data Valid

window

Data Valid

window

Data Valid

window

Upper Byte

Lower Byte

Data Valid

window

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Data Output Timing Diagrams

Figure 42: Data Output Timing – tAC and tDQSCK

Notes: 1. tDQSCK is the DQS output window relative to CK and is the “long-term” component of

DQS skew.

2. DQ transitioning after DQS transition define tDQSQ window.

3. All DQ must transition by tDQSQ after DQS transitions, regardless of tAC.

4. tAC is the DQ output window relative to CK, and is the “long-term” component of DQ

skew.

5. tLZ (MIN) and tAC (MIN) are the first valid signal transition.

6. tHZ (MAX),and tAC (MAX) are the latest valid signal transition.

7. READ command with CL = 2 issued at T0.

CK#

DQS, or LDQS/UDQS2

T07T1 T2 T3 T4 T5

T2n T3n T4n T5n T6

tRPST

tLZ (MIN)

tDQSCK1 (MAX)

tDQSCK1 (MIN)

tDQSCK1 (MAX)

tDQSCK1 (MIN)

tHZ(MAX)

tRPRE

DQ (Last data valid)

DQ (First data valid)

All DQ values, collectively3

tAC

(MIN) tAC

(MAX)

tLZ (MIN) tHZ (MAX)

T2n T3n T4n T5n

T2n

T3n

T4n

T5n

T2 T3 T4 T5

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Data Output Timing Diagrams

Figure 43: Data Input Timing

Notes: 1. tDSH (MIN) generally occurs during tDQSS (MIN).

2. tDSS (MIN) generally occurs during tDQSS (MAX).

3. WRITE command issued at T0.

4. For x16, LDQS controls the lower byte and UDQS controls the upper byte.

DQS

tDQSS

tDQSH tWPST

tDH

tDS

tDQSL

tDSS2tDSH1

tDSH1tDSS2

CK#

T1 T1n T2 T2n T3

DON’T CARE

TRANSITIONING DATA

WPRE

WPRES

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Initialization

To ensure device operation the DRAM must be initialized as described below:

1. Simultaneously apply power to VDD and VDDQ.

2. Apply VREF and then VTT power.

3. Assert and hold CKE at a LVCMOS logic low.

4. Provide stable CLOCK signals.

5. Wait at least 200µs.

6. Bring CKE high and provide at least one NOP or DESELECT command. At this point

the CKE input changes from a LVCMOS input to a SSTL2 input only and will remain a

SSTL_2 input unless a power cycle occurs.

7. Perform a PRECHARGE ALL command.

8. Wait at least tRP time, during this time NOPs or DESELECT commands must be given.

9. Using the LMR command program the Extended Mode Register (E0 = 0 to enable the

DLL and E1 = 0 for normal drive or E1 = 1 for reduced drive, E2 through En must be set

to 0; where n = most significant bit).

10. Wait at least tMRD time, only NOPs or DESELECT commands are allowed.

11. Using the LMR command program the Mode Register to set operating parameters

and to reset the DLL. Note at least 200 clock cycles are required between a DLL reset

and any READ command.

12. Wait at least tMRD time, only NOPs or DESELECT commands are allowed.

13. Issue a PRECHARGE ALL command.

14. Wait at least tRP time, only NOPs or DESELECT commands are allowed.

15. Issue an AUTO REFRESH command (Note this may be moved prior to step 13).

16. Wait at least tRFC time, only NOPs or DESELECT commands are allowed.

17. Issue an AUTO REFRESH command (Note this may be moved prior to step 13).

18. Wait at least tRFC time, only NOPs or DESELECT commands are allowed.

19. Although not required by the Micron device, JEDEC requires a LMR command to clear

the DLL bit (set M8 = 0). If a LMR command is issued the same operating parameters

should be utilized as in step 11.

20. Wait at least tMRD time, only NOPs or DESELECT commands are allowed.

21. At this point the DRAM is ready for any valid command. Note 200 clock cycles are

required between step 11 (DLL Reset) and any READ command.

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Initialization

Figure 44: Initialization Flow Diagram

and V

Q Ramp

Apply V

REF

and V

CKE must be LVCMOS Low

Apply stable CLOCKs

Bring CKE High with a NOP command

Wait at least 200us

PRECHARGE ALL

Assert NOP or DESELECT for tRP time

Configure Extended Mode Register

Configure Load Mode Register and reset DLL

Assert NOP or DESELECT for tMRD time

PRECHARGE ALL

Issue AUTO REFRESH command

Assert NOP or DESELECT for tRFC time

Optional LMR command to clear DLL bit

Assert NOP or DESELECT for tMRD time

DRAM is ready for any valid command

Step

Assert NOP or DESELECT commands for tRFC

Issue AUTO REFRESH command

Assert NOP or DESELECT for tRP time

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Timing Diagrams

Figure 45: Initialize and Load Mode Registers

Notes: 1. V

is not applied directly to the device; however,

VTD should be greater than or equal to zero to avoid

device latch-up. V

Q, V

, and V

REF

must be equal to or less than V

+ 0.3V. Alternatively, V

may be

1.35V maximum during power-up, even if V

Q are 0V, provided a minimum of 42

of series resis-

tance is used between the V

supply and the input pin. Once initialized, V

REF

must always be powered

within the specified range.

2. Reset the DLL with A8 = H while programming the operating parameters.

MRD is required before any command can be applied, and 200 cycles of CK are required before a READ

command can be issued.

4. The two AUTO REFRESH commands at Td0 and Te0 may be applied following the LOAD MODE

5. Although not required by the Micron device, JEDEC specifies issuing another LMR command (A8

= L) prior to activating any bank. If another LMR command is issued, the same operating param-

eters must be used as previously issued.

6. PRE = PRECHARGE command; LMR = LOAD MODE REGISTER command; AR = AUTO REFRESH

command; ACT = ACTIVE command; RA = Row Address; and BA = Bank Address.

VTD

CKE

LVCMOS

LOW LEVEL

BA0, BA1

200 cycles of CK

Load Extended

Mode Register

Load Mode

tMRD tMRD tRP tRFC tRFC

Power-up: V

and CK stable

T = 200µs

High-Z

DQS High-Z

A0-A9,

A11, A12

A10

ALL BANKS

CK#

REF

COMMAND

LMRNOP PRELMR AR AR ACT

tIS tIH

BA0 = H,

BA1 = L

tIS tIH

BA0 = L,

BA1 = L

tIS tIH

(

)(

)

(

)(

)

(

)(

)

(

)(

)

CODE CODE

tIS tIH

CODE CODE

PRE

ALL BANKS

tIS tIH

T0 T1 Ta0 Tb0 Tc0 Td0 Te0 Tf0

(

)(

)

DON’T CARE

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

tRP

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Timing Diagrams

Figure 46: Power-Down Mode

Notes: 1. Once initialized, VREF must always be powered within the specified range.

2. If this command is a PRECHARGE (or if the device is already in the idle state), then the

power-down mode shown is precharge power-down. If this command is an ACTIVE (or if at

least one row is already active), then the power-down mode shown is active power-down.

3. No column accesses are allowed to be in progress at the time power-down is entered.

CK#

COMMAND VALID2NOP

ADDR

CKE1

DQS

VALID

tCK tCH tCL

tIS

tIH

tIS

tIS tIH

tIH tIS

Enter3

Power-Down

Mode

Exit

Power-Down

Mode

tREFC

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

T0 T1 Ta0 Ta1 Ta2T2

NOP

DON’T CARE

(

)(

)

(

)(

)

VALIDVALID

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Timing Diagrams

Figure 47: Auto Refresh Mode

Notes: 1. PRE = PRECHARGE; ACT = ACTIVE; AR = AUTO REFRESH; RA = Row Address; and BA = Bank

Address.

2. NOP commands are shown for ease of illustration; other valid commands may be possible

at these times. CKE must be active during clock positive transitions.

3. NOP or COMMAND INHIBIT are the only commands allowed until after tRFC time; CKE

must be active during clock positive transitions.

4. “Don’t Care” if A10 is HIGH at this point; A10 must be HIGH if more than one bank is

active (i.e., must precharge all active banks).

5. DM, DQ, and DQS signals are all “Don’t Care”/High-Z for operations shown.

6. The second AUTO REFRESH is not required and is only shown as an example of two back-

to-back AUTO REFRESH commands.

CK#

COMMAND

1NOP2

VALID VALID

NOP 2NOP2

PRE

CKE

A0-A9,

A11, A12

A10

BA0, BA1

1Bank(s)4BA

AR NOP2, 3 AR6NOP2, 3 ACTNOP2

ONE BANK

ALL BANKS

DQS

tRFC

tRP tRFC

T0 T1 T2 T3 T4 Ta0 Tb0

Ta1 Tb1 Tb2

DON’T CARE

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Timing Diagrams

Figure 48: Self Refresh Mode

Notes: 1. Clock must be stable until after the SELF REFRESH command has been registered. A change

in clock frequency is allowed before Ta0, provided it is within the specified tCK limits.

Regardless, the clock must be stable before exiting self refresh mode. That is, the clock

must be cycling within specifications by Ta0.

2. NOPs are interchangeable with DESELECT commands; AR = AUTO REFRESH command.

3. Auto refresh is not required at this point, but is highly recommended.

4. Device must be in the all banks idle state prior to entering self refresh mode.

5. tXSNR is required before any non-READ command can be applied; only NOP or DESELECT

commands are allowed until Tb1.

6. tXSRD (200 cycles of a valid CK and CKE = high) is required before any READ command can

be applied.

7. As a general rule, any time self refresh mode is exited, the DRAM may not re-enter the self

refresh mode until all rows have been refreshed via the AUTO REFRESH command at the

distributed refresh rate, tREFI, or faster. However, self refresh mode may be re-entered

anytime after exiting, if the following conditions are all met:

a.The DRAM had been in the Self Refresh Mode for a minimum of 200ms prior to exit-

ing.

b.tXSNR and tXSRD are not violated.

c.At least two AUTO REFRESH commands are performed during each tREFI interval while

the DRAM remains out of Self Refresh mode.

8. If the clock frequency is changed during self refresh mode, a DLL reset is required upon

exit.

9. Once initialized, including during Self-Refresh mode, VREF must always be powered within

the specified range.

CK#

COMMAND

2NOP AR

ADDR

CKE

DQS

NOP

tRP

tCH tCL tCK

tIS

tIH

tIS tIH tIS

Enter Self Refresh Mode

Exit Self Refresh Mode

T0 T11Ta1

(

)(

)

DON’T CARE

Ta0

tXSRD6

(

)(

)

(

)(

)

(

)(

)

(

)(

)

NOP

VALID3VALID

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

tXSNR5

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

(

)(

)

Ta2 Tb1 Tb2 Tc1

VALID VALID

VALID

tIS tIH

(

)(

)

(

)(

)

VALID

(

)(

)

(

)(

)

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Timing Diagrams

Figure 49: Bank Read - Without Auto Precharge

Notes: 1. DOn = data-out from column n; subsequent elements are provided in the programmed

order.

2. Burst length = 4 in the case shown.

3. Disable auto precharge.

4. “Don’t Care” if A10 is HIGH at T5.

5. PRE = PRECHARGE; ACT = ACTIVE; RA = Row Address; and BA = Bank Address.

6. NOP commands are shown for ease of illustration; other commands may be valid at these

times.

7. The PRECHARGE command can only be applied at T5 if tRAS minimum is met.

8. Refer to Figure 40 on page 77, Figure 41 on page 78, and Figure 42 on page 79 for

detailed DQS and DQ timing.

CK#

CKE

A10

BA0, BA1

tCK tCH tCL

tIS

tIH

tIS

tIH

tIS tIH

tRCD

tRAS7

tRC

tRP

CL = 2

T0 T1 T2 T3 T4 T5 T5n T6nT6 T7 T8

DQ1

DQS

Case 1: tAC

(

MIN)

and tDQSCK

(

MIN)

Case 2: tAC

(

MAX)

and tDQSCK

(

MAX)

DQ1

DQS

RPRE

tRPRE

tRPST

DQSCK

(

MIN)

DQSCK

(

MAX)

(

MIN)

(

MIN)

(

MIN)

(

MAX)

(

MAX)

NOP6

COMMAND5

ACT

Col n

READ2PRE

Bank x

Bank xBank x4

ACT

Bank x

NOP6NOP6NOP6

ONE BANK

ALL BANKS

DON’T CARE TRANSITIONING DATA

x4: A0-A9, A11

x8: A0-A9

x16: A0-A8

x4: A12

x8: A11, A12

x16: A9, A11, A12

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Timing Diagrams

Figure 50: Bank Read - With Auto Precharge

Notes: 1. DOn = data-out from column n; subsequent elements are provided in the programmed

order.

2. Burst length = 4 in the case shown.

3. Enable auto precharge.

4. ACT = ACTIVE; RA = Row Address; and BA = Bank Address.

5. NOP commands are shown for ease of illustration; other commands may be valid at these

times.

6. The READ command can only be applied at T3 if tRAP is satisfied at T3.

7. tRP starts only after tRAS has been satisfied.

8. Refer to Figure 40 on page 77, Figure 41 on page 78, and Figure 42 on page 79 for

detailed DQS and DQ timing.

CK#

CKE

A10

BA0, BA1

IS IH

RP7

CL = 2

T0 T1 T2 T3 T4 T5 T5n T6nT6 T7 T8

DQ1

DQS

Case 1: tAC (

MIN)

and tDQSCK (

MIN)

Case 2: tAC

(

MAX)

and tDQSCK

(

MAX)

DQ1

DQS

RPRE

RPST

tDQSCK

(

MIN)

tDQSCK

(

MAX)

(

MIN)

(

MIN)

(

MAX)

(

MAX)

NOP5

COMMAND4

ACT

Col n

READ2,6 NOP5

Bank x

ACT

Bank x

NOP5NOP5NOP5

DON’T CARE TRANSITIONING DATA

x4: A0-A9, A11

x8: A0-A9

x16: A0-A8

x4: A12

x8: A11, A12

x16: A9, A11, A12

tRAS

(

MIN)

tRCD, tRAP6

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Timing Diagrams

Figure 51: Bank Write - Without Auto Precharge

Notes: 1. DI n = data-in from column n; subsequent elements are provided in the programmed

order.

2. Burst length = 4 in the case shown.

3. Disable auto precharge.

4. “Don’t Care” if A10 is HIGH at T8.

5. PRE = PRECHARGE; ACT = ACTIVE; RA = Row Address; and BA = Bank Address.

6. NOP commands are shown for ease of illustration; other commands may be valid at these

times.

7. See Figure 43, Data Input Timing, on page 80, for detailed DQ timing.

8. Although not required by the Micron device, JEDEC specifies that DQS be a valid HIGH,

LOW or some point on a valid transition on or before this clock edge (T3n).

CK#

CKE

A10

BA0, BA1

tCK tCH tCL

tIS

tIH

tIS

tIH

tIS tIH

tRCD

tRAS tRP

tWR

T0 T1 T2 T3 T4 T5 T5n T6 T7 T8T4n

NOP6

COMMAND

ACT

Col n

WRITE2NOP6

ONE BANK

ALL BANKS

Bank x

PRE

Bank x

NOP6NOP6NOP6

tDQSL tDQSH tWPST

Bank x4

DQS

tDS tDH

DON’T CARE TRANSITIONING DATA

tDQSS (NOM)

WPRE

WPRES

x4: A0-A9, A11

x8: A0-A9

x16: A0-A8

x4: A12

x8: A11, A12

x16: A9, A11, A12

T3n

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Timing Diagrams

Figure 52: Bank Write - With Auto Precharge

Notes: 1. DIn = data-out from column n; subsequent elements are provided in the programmed

order.

2. Burst length = 4 in the case shown.

3. Enable auto precharge.

4. ACT = ACTIVE;, RA = Row Address; and BA = Bank Address.

5. NOP commands are shown for ease of illustration; other commands may be valid at these

times.

6. See Figure 43, Data Input Timing, on page 80, for detailed DQ timing.

7. Although not required by the Micron device, JEDEC specifies that DQS be a valid HIGH,

LOW or some point on a valid transition on or before this clock edge (T3n).

CK#

CKE

A10

BA0, BA1

tCK tCH tCL

tIS

tIH

tIS

tIH

tIS tIH

tRCD

tRAS tRP

tWR

T0 T1 T2 T3 T4 T5 T5n T6 T7 T8T4n

NOP5

COMMAND4

ACT

Col n

WRITE2NOP5

Bank x

NOP5

Bank x

NOP5NOP5NOP5

tDQSL tDQSH tWPST

DQ1

DQS

tDS tDH

tDQSS (NOM)

DON’T CARE TRANSITIONING DATA

WPRES

WPRE

x4: A0-A9, A11

x8: A0-A9

x16: A0-A8

x4: A12

x8: A11, A12

x16: A9, A11, A12

T3n

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Timing Diagrams

Figure 53: Write – DM Operation

Notes: 1. DIn = data-in from column n; subsequent elements are provided in the programmed order.

2. Burst length = 4 in the case shown.

3. Disable auto precharge.

4. “Don’t Care” if A10 is HIGH at T8.

5. PRE = PRECHARGE; ACT = ACTIVE; RA = Row Address; and BA = Bank Address.

6. NOP commands are shown for ease of illustration; other commands may be valid at these

times.

7. See Figure 43, Data Input Timing, on page 80, for detailed DQ timing.

8. Although not required by the Micron device, JEDEC specifies that DQS be a valid HIGH,

LOW or some point on a valid transition on or before this clock edge (T3n).

CK#

CKE

A10

BA0, BA1

RCD

RAS tRP

tWR

T0 T1 T2 T3 T4 T5 T5n T6 T7 T8T4n

NOP6

COMMAND

ACT

Col n

WRITE2NOP6

ONE BANK

ALL BANKS

Bank x

PRE

Bank x

NOP6NOP6NOP6

DQSL

DQSH

WPST

Bank x4

DQS

DON’T CARE TRANSITIONING DATA

DQSS (NOM)

WPRES

WPRE

x4: A0-A9, A11

x8: A0-A9

x16: A0-A8

x4: A12

x8: A11, A12

x16: A9, A11, A12

T3n

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Package Drawings

Figure 54: 66-Pin Plastic TSOP (400 mil)

Notes: 1. All dimensions in millimeters.

2. Package width and length do not include mold protrusion; allowable mold protrusion is

0.25mm per side.

SEE DETAIL A

0.10

0.65 TYP

0.71

10.16 ±0.08

0.15

0.50 ±0.10

PIN #1 ID

DETAIL A

22.22 ± 0.08

0.32 ±0.075 TYP

+0.03

-0.02

+0.10

-0.05

1.20 MAX

0.10

0.25

11.76 ±0.10

0.80 TYP

0.10 (2X)

GAGE PLANE

8000 S. Federal Way, P.O. Box 6, Boise, ID 83707-0006, Tel: 208-368-3900

prodmktg@micron.com www.micron.com Customer Comment Line: 800-932-4992

Micron, the M logo, and the Micron logo are trademarks of Micron Technology, Inc.

All other trademarks are the property of their respective owners.

This data sheet contains minimum and maximum limits specified over the complete power supply and temperature range

for production devices. Although considered final, these specifications are subject to change, as further product

development and data characterization sometimes occur.

256Mb: x4, x8, x16 DDR SDRAM

Package Drawings

09005aef8076894f Micron Technology, Inc., reserves the right to change products or specifications without notice.

Figure 55: 60-Ball FBGA (8x14mm)

Note: All dimensions are in millimeters.

PIN A1 ID

1.20 MAX

MOLD COMPOUND: EPOXY NOVOLAC

SUBSTRATE: PLASTIC LAMINATE

SOLDER BALL MATERIAL: EUTECTIC 62% Sn, 36% Pb, 2%Ag

SOLDER BALL PAD: Ø .33mm

14.00 ±0.10

BALL A1

BALL A9

PIN A1 ID

1.00 TYP

0.80 TYP

7.00 ±0.05

8.00 ±0.10

4.00 ±0.05

3.20 ±0.05

5.50 ±0.05

0.850 ±0.075

SEATING PLANE

11.00

6.40

0.10 C

60X ∅0.45

SOLDER BALL DIAMETER

REFERS TO POST REFLOW

CONDITION. THE PRE-

REFLOW DIAMETER IS Ø 0.40