98CX8297B1-BLS2C000 - MARVELL TECHNOLOGY GROUP

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

256Mb: x4, x8, x16 DDR SDRAM

Features

PDF: 09005aef80768abb/Source: 09005aef82a95a3a 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

Features

•V

DD = 2.5V ±0.2V; VDDQ = 2.5V ±0.2V

VDD = 2.6V ±0.1V; VDDQ = 2.6V ±0.1V (DDR400)1

• Bidirectional data strobe (DQS) transmitted/

received with data, that is, 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 (BL): 2, 4, or 8

• Auto refresh

–64ms, 8192-cycle

• Longer-lead TSOP for improved reliability (OCPL)

• 2.5V I/O (SSTL_2-compatible)

• Concurrent auto precharge option supported

•tRAS lockout supported (tRAP = tRCD)

Notes: 1. DDR400 devices operating at < DDR333

conditions can use VDD/VDDQ = 2.5V +0.2V.

2. Available only on Revision K.

3. Available only on Revision M.

4. Not recommended for new designs.

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 (Pb-free) P

• Plastic package

–60-ball FBGA (8mm x 12.5mm) CV

–60-ball FBGA (8mm x 12.5mm)

(Pb-free)

• Timing – cycle time

–5ns @ CL = 3 (DDR400) -5B3

–6ns @ CL = 2.5 (DDR333) FBGA only -62

–6ns @ CL = 2.5 (DDR333) TSOP only -6T2

• Self refresh

–Standard None

–Low-power self refresh L

• Temperature rating

–Commercial (0qC to +70qC) None

–Industrial (–40qC to +85qC) IT

• Revision

–x4, x8, x16 :K4

–x4, x8, x16 :M

Table 1: Key Timing Parameters

CL = CAS (READ) latency; MIN clock rate with 50% duty cycle at CL = 2 (-75E, -75Z), CL = 2.5 (-6, -6T, -75), and

CL = 3 (-5B)

Speed Grade

Clock Rate (MHz)

Data-Out Window

Access

Window

DQS–DQ

SkewCL = 2 CL = 2.5 CL = 3

-5B 133 167 200 1.6ns ±0.70ns 0.40ns

-6 133 167 n/a 2.1ns ±0.70ns 0.40ns

6T 133 167 n/a 2.0ns ±0.70ns 0.45ns

-75E/-75Z 133 133 n/a 2.5ns ±0.75ns 0.50ns

-75 100 133 n/a 2.5ns ±0.75ns 0.50ns

PDF: 09005aef80768abb/Source: 09005aef82a95a3a Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Features

Notes: 1. The -5B device is backward compatible with all slower speed grades. The voltage range of

-5B device operating at slower speed grades is VDD = VDDQ = 2.5V ± 0.2V.

Figure 1: 256Mb DDR SDRAM Part Numbers

Table 2: Addressing

Parameter 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 address 8K (A[12:0]) 8K (A[12:0]) 8K (A[12:0])

Bank address 4 (BA[1:0]) 4 (BA[1:0]) 4 (BA[1:0])

Column address 2K (A[9:0], A11) 1K (A[9:0]) 512 (A[8:0])

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)

-5B1Yes 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 ––––YesYes

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

Example Part Number: MT46V16M16P-6T:M

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 (Pb-free)

Speed Grade

tCK = 5ns, CL = 3

tCK = 6ns, CL = 2.5

-5B

-6

-6T

Operating Temp.

Commercial

Industrial

ConfigurationMT46V Package Speed

Revision

Sp.

Op. Temp.

Revision

x4, x8, x16

8mm x 12.5mm FBGA

8mm x 12.5mm FBGA (Pb-free)

PDF: 09005aef80768abb/Source: 09005aef82a95a3a Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Features

FBGA Part Marking System

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

marking that is different from the part number. For a quick conversion of an FBGA code,

see the FBGA Part Marking Decoder on Micron’s Web site: www.micron.com.

PDF: 09005aef80768abb/Source: 09005aef82a95a3a Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

Table of Contents

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

State Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

General Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

Functional Block Diagrams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

Pin and Ball Assignments and Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

Package Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

Electrical Specifications – IDD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

Electrical Specifications – DC and AC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18

Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35

Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43

DESELECT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47

NO OPERATION (NOP). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47

LOAD MODE REGISTER (LMR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47

ACTIVE (ACT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48

READ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49

WRITE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50

PRECHARGE (PRE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51

BURST TERMINATE (BST) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51

AUTO REFRESH (AR). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51

SELF REFRESH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51

Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52

INITIALIZATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52

REGISTER DEFINITION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55

ACTIVE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59

READ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60

WRITE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72

PRECHARGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85

AUTO REFRESH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .87

SELF REFRESH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .88

Power-down (CKE Not Active) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .90

PDF: 09005aef80768abb/Source: 09005aef82a95a3a 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: Simplified State Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Figure 6: 66-Pin TSOP Pin Assignments (Top View) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

Figure 9: 60-Ball FBGA (8mm x 12.5mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

Figure 10: Input Voltage Waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Figure 11: SSTL_2 Clock Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

Figure 12: Derating Data Valid Window (tQH – tDQSQ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

Figure 13: Full Drive Pull-Down Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

Figure 14: Full Drive Pull-Up Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

Figure 15: Reduced Drive Pull-Down Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

Figure 16: Reduced Drive Pull-Up Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

Figure 17: Activating a Specific Row in a Specific Bank. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48

Figure 18: READ Command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49

Figure 19: WRITE Command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50

Figure 20: PRECHARGE Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51

Figure 21: INITIALIZATION Flow Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53

Figure 22: INITIALIZATION Timing Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54

Figure 23: Mode Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55

Figure 24: CAS Latency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57

Figure 25: Extended Mode Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59

Figure 26: Example: Meeting tRCD (tRRD) MIN When 2 < tRCD (tRRD) MIN/tCK d3 . . . . . . . . . . . . . . . . . . . . . .60

Figure 29: Nonconsecutive READ Bursts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64

Figure 30: Random READ Accesses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65

Figure 31: Terminating a READ Burst . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66

Figure 32: READ-to-WRITE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67

Figure 33: READ-to-PRECHARGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68

Figure 34: Bank READ – Without Auto Precharge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69

Figure 35: x4, x8 Data Output Timing – tDQSQ, tQH, and Data Valid Window . . . . . . . . . . . . . . . . . . . . . . . . . . . .70

Figure 36: x16 Data Output Timing – tDQSQ, tQH, and Data Valid Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71

Figure 37: Data Output Timing – tAC and tDQSCK. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72

Figure 38: WRITE Burst. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74

Figure 39: Consecutive WRITE-to-WRITE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75

Figure 41: Random WRITE Cycles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76

Figure 42: WRITE-to-READ – Uninterrupting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77

Figure 43: WRITE-to-READ – Interrupting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .78

Figure 44: WRITE-to-READ – Odd Number of Data, Interrupting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .79

Figure 45: WRITE-to-PRECHARGE – Uninterrupting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .80

Figure 46: WRITE-to-PRECHARGE – Interrupting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .81

Figure 47: WRITE-to-PRECHARGE – Odd Number of Data, Interrupting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .82

Figure 48: Bank WRITE – Without Auto Precharge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .83

Figure 49: WRITE – DM Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84

Figure 50: Data Input Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85

Figure 51: Bank READ – with Auto Precharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86

Figure 52: Bank WRITE – with Auto Precharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .87

Figure 53: Auto Refresh Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .88

Figure 54: Self Refresh Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .89

PDF: 09005aef80768abb/Source: 09005aef82a95a3a Micron Technology, Inc., reserves the right to change products or specifications without notice.

256Mb: x4, x8, x16 DDR SDRAM

List of Tables

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

Table 2: Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

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

Table 4: Pin and Ball Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

Table 5: IDD Specifications and Conditions (x4, x8, x16: -5B, -6, -6T) – Die Revision K . . . . . . . . . . . . . . . . . . .16

Table 6: IDD Specifications and Conditions (x4, x8, x16: -5B, -6, -6T) – Die Revision M. . . . . . . . . . . . . . . . . . .17

Table 7: Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18

Table 8: DC Electrical Characteristics and Operating Conditions (-5B). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18

Table 9: DC Electrical Characteristics and Operating Conditions (-6, -6T, -75E, -75Z, -75) . . . . . . . . . . . . . . .19

Table 10: AC Input Operating Conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Table 11: Clock Input Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

Table 12: Capacitance (x4, x8 TSOP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

Table 13: Capacitance (x4, x8 FBGA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

Table 14: Capacitance (x16 TSOP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

Table 15: Capacitance (x16 FBGA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

Table 16: Electrical Characteristics and Recommended AC Operating Conditions (-5B) . . . . . . . . . . . . . . . . . .23

Table 17: Electrical Characteristics and Recommended AC Operating Conditions (-6). . . . . . . . . . . . . . . . . . . .25

Table 18: Electrical Characteristics and Recommended AC Operating Conditions (-6T) . . . . . . . . . . . . . . . . . .27

Table 19: Electrical Characteristics and Recommended AC Operating Conditions (-75E) . . . . . . . . . . . . . . . . .29

Table 20: Electrical Characteristics and Recommended AC Operating Conditions (-75Z) . . . . . . . . . . . . . . . . .31

Table 21: Electrical Characteristics and Recommended AC Operating Conditions (-75) . . . . . . . . . . . . . . . . . .33

Table 22: Input Slew Rate Derating Values for Addresses and Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

Table 23: Input Slew Rate Derating Values for DQ, DQS, and DM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

Table 24: Normal Output Drive Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41

Table 25: Reduced Output Drive Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42

Table 26: Truth Table 1 – Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43

Table 27: Truth Table 2 – DM Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43

Table 28: Truth Table 3 – Current State Bank n – Command to Bank n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44

Table 29: Truth Table 4 – Current State Bank n – Command to Bank m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45

Table 30: Command Delays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46

Table 31: Truth Table 5 – CKE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47

Table 32: Burst Definition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56

Table 33: CAS Latency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58

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256Mb: x4, x8, x16 DDR SDRAM

State Diagram

Figure 1: Simplified State Diagram

Note: This diagram represents operations within a single bank only and does not capture concur-

rent operations in other banks.

Power

applied

REFS

LMR REFA

REFSX

ACT

CKE LOW

CKEL

CKE HIGH

CKEH

PRE

Precharge

all banks

EMR

Self

refresh

Idle

all banks

precharged

Row

active

Burst

stop

Read

Read A

Automatic sequence

Command sequence

Write

WRITE

Write A

WRITE A

Precharge

PREALL

Active

power-

down

Precharge

power-

down

Auto

refresh

PRE

WRITE A READ A

READ A

PRE

READ A

READ

BST

ACT = ACTIVE

BST = BURST TERMINATE

CKEH = Exit power-down

CKEL = Enter power-down

EMR = Extended mode register

LMR = LOAD MODE REGISTER

MR = Mode register

PRE = PRECHARGE

PREALL = PRECHARGE all banks

READ A = READ with auto precharge

REFA = AUTO REFRESH

REFS = Enter self refresh

REFSX = Exit self refresh

WRITE A = WRITE with auto precharge

PRE

LMR

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256Mb: x4, x8, x16 DDR SDRAM

Functional Description

The 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 inter-

face designed to transfer two data words per clock cycle at the I/O pins. A single read or

write access for the DDR SDRAM effectively 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.

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 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.

Commands (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 may then

be 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

precharge 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 providing high effective 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.

General Notes

• The functionality and the timing specifications discussed in this data sheet are for the

DLL-enabled mode of operation.

• 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

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

byte. For the lower byte (DQ[7:0]) DM refers to LDM and DQS refers to LDQS. For the

upper byte (DQ[15:8]) DM refers to UDM and DQS refers to UDQS.

• Complete functionality is described throughout the document and any page or

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

requirements.

• Any specific requirement takes precedence over a general statement.

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256Mb: x4, x8, x16 DDR SDRAM

Functional Block Diagrams

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

containing 268,435,456 bits. It is internally configured as a 4-bank DRAM.

Figure 1: 64 Meg x 4 Functional Block Diagram

RAS#

CAS#

Row-

address

MUX

CS#

WE#

CK#

A[12:0],

BA[1:0]

CKE

1024

(x8)

8192

out

DQS

MUX

DQ[3:0]

DQS

WRITE

FIFO

and

drivers

Control

logic

Mode registers

Command

decode

Refresh

counter

Address

Bank

control

logic

Column-

address

counter/

latch

Column

decoder

I/O gating

DM mask logic

Bank 0

row-

address

latch

and

decoder

Bank 0

memory

array

(8192 x 1024 x 8)

Sense amplifiers

Bank 1

Bank 2

Bank 3

READ

latch

Data

DLL

Drivers

DQS

generator

Input

registers

Rcvrs

Data

Mask

Column 0

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256Mb: x4, x8, x16 DDR SDRAM

Functional Block Diagrams

Figure 2: 32 Meg x 8 Functional Block Diagram

Figure 3: 16 Meg x 16 Functional Block Diagram

RAS#

CAS#

ROW-

ADDRESS

MUX

CS#

WE#

CK#

CONTROL

LOGIC

COLUMN-

ADDRESS

COUNTER/

LATCH

MODE REGISTERS

COMMAND

DECODE

A[12:0],

BA[1:0]

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

Out

DATA

DQS

MASK

DATA

DRVRS

DLL

MUX

DQS

GENERATOR

DQ[7:0]

DQS

READ

LATCH

WRITE

FIFO

DRIVERS

COL0

RAS#

CAS#

ROW-

ADDRESS

MUX

CS#

WE#

CK#

CONTROL

LOGIC

COLUMN-

ADDRESS

COUNTER/

LATCH

MODE REGISTERS

COMMAND

DECODE

A[12:0],

BA[1:0]

CKE

ADDRESS

256

(x32)

8192

I/O GATING

DM MASK LOGIC

COLUMN

DECODER

BANK0

MEMORY

ARRAY

(8192 x 256 x 32)

BANK0

ROW-

ADDRESS

LATCH

DECODER

8192

SENSE AMPLIFIERS

BANK

CONTROL

LOGIC

BANK1

BANK2

BANK3

REFRESH

COUNTER

INPUT

REGISTERS

RCVRS

Out

DATA

DQS

MASK

DATA

DRVRS

DLL

MUX

DQS

GENERATOR

DQ[15:0]

LDQS

UDQS

READ

LATCH

WRITE

FIFO

DRIVERS

COL0

LDM,

UDM

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256Mb: x4, x8, x16 DDR SDRAM

Pin and Ball Assignments and Descriptions

Figure 4: 66-Pin TSOP Pin Assignments (Top View)

x4 x16 x4x8x16

VSS

DQ15

VSSQ

DQ14

DQ13

VDDQ

DQ12

DQ11

VSSQ

DQ10

DQ9

VDDQ

DQ8

VSSQ

UDQS

DNU

VREF

VSS

UDM

CK#

CKE

A12

A11

VSS

DQ7

VSSQ

DQ6

VDDQ

DQ5

VSSQ

DQ4

VDDQ

VSSQ

DQS

DNU

VREF

VSS

CK#

CKE

A12

A11

VSS

VSSQ

DQ3

VDDQ

VSSQ

DQ2

VDDQ

VSSQ

DQS

DNU

VREF

VSS

CK#

CKE

A12

A11

VSS

VDD

DQ0

VDDQ

DQ1

DQ2

VSSQ

DQ3

DQ4

VDDQ

DQ5

DQ6

VSSQ

DQ7

VDDQ

LDQS

VDD

DNU

LDM

WE#

CAS#

RAS#

CS#

BA0

BA1

A10/AP

VDD

DQ0

VDDQ

DQ1

VSSQ

DQ2

VDDQ

DQ3

VSSQ

VDDQ

VDD

DNU

WE#

CAS#

RAS#

CS#

BA0

BA1

A10/AP

VDD

VDDQ

DQ0

VSSQ

VDDQ

DQ1

VSSQ

VDDQ

VDD

DNU

WE#

CAS#

RAS#

CS#

BA0

BA1

A10/AP

VDD

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256Mb: x4, x8, x16 DDR SDRAM

Pin and Ball Assignments and Descriptions

Figure 5: 60-Ball FBGA Ball Assignments (Top View)

VSSQ

DQ14

DQ12

DQ10

DQ8

REF

DQ15

VDDQ

VSSQ

VDDQ

VSSQ

A12

A11

DQ13

DQ11

DQ9

UDQS

UDM

CK#

CKE

DQ2

DQ4

DQ6

LDQS

LDM

WE#

RAS#

BA1

DQ0

VSSQ

VDDQ

VSSQ

VDDQ

CAS#

CS#

BA0

A10

VDDQ

DQ1

DQ3

DQ5

DQ7

DNU

x16 (Top View)

VSSQ

REF

VDDQ

VSSQ

VDDQ

VSSQ

A12

A11

DQ3

DQ2

DQS

CK#

CKE

DQ0

DQ1

WE#

RAS#

BA1

VSSQ

VDDQ

VSSQ

VDDQ

CAS#

CS#

BA0

A10

VDDQ

DNU

x4 (Top View)

VSSQ

REF

DQ7

VDDQ

VSSQ

VDDQ

VSSQ

A12

A11

DQ6

DQ5

DQ4

DQS

CK#

CKE

DQ1

DQ2

DQ3

WE#

RAS#

BA1

DQ0

VSSQ

VDDQ

VSSQ

VDDQ

CAS#

CS#

BA0

A10

VDDQ

DNU

x8 (Top View)

12 3456789

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256Mb: x4, x8, x16 DDR SDRAM

Pin and Ball Assignments and Descriptions

Table 1: Pin and Ball Descriptions

Symbol Type Description

A[12:0] 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 BA[1:0]) or all banks (A10

HIGH). The address inputs also provide the op-code during a LOAD MODE REGISTER command.

BA[1:0] Input Bank address inputs: BA[1:0] define to which bank an ACTIVE, READ, WRITE, or PRECHARGE

command is being applied. BA[1:0] also define which mode register (mode register or extended

mode register) is loaded during the LOAD MODE REGISTER (LMR) command.

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#.

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.

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.

LDM, UDM

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 x16 devices, LDM is DM for DQ[7:0], and UDM is DM for DQ[15:8]. Pin 20 is NC on

x4 and x8 devices.

RAS#, CAS#,

WE#

Input Command inputs: RAS#, CAS#, and WE# (along with CS#) define the command being entered.

DQ[15:0] I/O Data input/output: Data bus for x16 devices.

DQ[7:0] I/O Data input/output: Data bus for x8 devices.

DQ[3:0] I/O Data input/output: Data bus for x4 devices.

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 x16 devices, LDQS is DQS for DQ[7:0],

and UDQS is DQS for DQ[15:8]. Pin 16 (E7) is NC for x4 and x8 devices.

VDD Supply Power supply.

VDDQ Supply DQ power supply: Isolated on the die for improved noise immunity.

VSS Supply Ground.

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

VREF Supply SSTL_2 reference voltage.

NC – No connect for x16, x8, x4: These pins should be left unconnected.

DNU – Do not use: Must float to minimize noise on VREF

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256Mb: x4, x8, x16 DDR SDRAM

Package Dimensions

Figure 6: 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

0.80 TYP

0.10 (2X)

GAGE PLANE

11.76 ± 0.20

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256Mb: x4, x8, x16 DDR SDRAM

Package Dimensions

Figure 7: 60-Ball FBGA (8mm x 12.5mm)

Notes: 1. All dimensions are in millimeters.

2. Topside part marking decoder can be found on Micron’s Web site.

Ball A1 ID

1.20 MAX

8 ±0.15

Ball A1 ID

60X Ø0.45

Solder ball material:

eutectic or SAC305.

Dimensions apply

to solder balls post-

reflow on Ø0.33

NSMD ball pads.

1 TYP

11 CTR 12.5 ±0.15

0.8 ±0.1

0.12 A A

Seating

plane

6.4 CTR

0.8 TYP

0.25 MIN

9 8 7 3 2 1

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256Mb: x4, x8, x16 DDR SDRAM

Electrical Specifications – I

Electrical Specifications – IDD

Tabl e 2: IDD Specifications and Conditions (x4, x8, x16: -5B, -6, -6T) – Die Revision K

VDDQ = 2.6V ±0.1V, VDD = 2.6V ±0.1V (-5B); VDDQ = 2.5V ±0.2V, VDD = 2.5V ±0.2V (-6, -6T);

0°C dTAd 70°C; Notes: 1–5, 11, 13, 15, 47; Notes appear on pages 35–40; See also Table 1 on page 18

Parameter/Condition Symbol -5B -6/6T Units Notes

Operating one-bank precharge current: 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

IDD0 100 90 mA 23, 48

Operating one-bank active-read-precharge current:

Burst = 4; tRC = tRC (MIN); tCK = tCK (MIN); IOUT =0mA;

Address and control inputs changing once per clock cycle

IDD1 120 115 mA 23, 48

Precharge power-down standby current: All banks idle;

Power-down mode; tCK = tCK (MIN); CKE = LOW

IDD2P 44 mA24, 33

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 =V

REF for DQ, DQS,

and DM

IDD2F 50 50 mA 51

Active power-down standby current: One bank active;

Power-down mode; tCK = tCK (MIN); CKE = LOW

IDD3P 35 30 mA 24, 33

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 55 mA 23

Operating burst read current: Burst = 2; Continuous

burst reads; One bank active; Address and control inputs

changing once per clock cycle; tCK = tCK (MIN); IOUT =0mA

IDD4R 180 160 mA 23, 48

Operating burst write current: Burst = 2; Continuous burst

writes; 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 180 160 mA 23

Auto refresh burst current: tREFC = tRFC (MIN) IDD5 160 160 mA 50

tREFC =7.8µs IDD5A 66 mA28, 50

Self refresh current: CKE d 0.2V Standard IDD6 44 mA 12

Low power (L) IDD6A 22 mA 12

Operating bank interleave read 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

IDD7 290 270 mA 23, 49

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Electrical Specifications – I

Tabl e 3: IDD Specifications and Conditions (x4, x8, x16: -5B, -6, -6T) – Die Revision M

VDDQ = 2.6V ±0.1V, VDD = 2.6V ±0.1V (-5B); VDDQ = 2.5V ±0.2V, VDD = 2.5V ±0.2V (-6, -6T);

0°C dTAd 70°C; Notes: 1–5, 11, 13, 15, 47; Notes appear on pages 35–40; See also Table 1 on page 18

Parameter/Condition Symbol -5B -6/6T Units Notes

Operating one-bank precharge current: 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

IDD0 75 65 mA 23, 48

Operating one-bank active-read-precharge current: Burst = 4;

tRC = tRC (MIN); tCK = tCK (MIN); IOUT = 0mA; Address and control

inputs changing once per clock cycle

IDD1 85 75 mA 23, 48

Precharge power-down standby current: All banks idle; Power-

down mode; tCK = tCK (MIN); CKE = LOW

IDD2P 4 4 mA 24, 33

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 =V

REF for DQ, DQS, and DM

IDD2F 23 23 mA 51

Active power-down standby current: One bank active; Power-

down mode; tCK = tCK (MIN); CKE = LOW

IDD3P 14 14 mA 24, 33

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 30 30 mA 23

Operating burst read current: Burst = 2; Continuous burst reads;

One bank active; Address and control inputs changing once per clock

cycle; tCK = tCK (MIN); IOUT =0mA

IDD4R 105 95 mA 23, 48

Operating burst write current: Burst = 2; Continuous burst writes;

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 105 95 mA 23

Auto refresh burst current: tREFC = tRFC (MIN) IDD5 115 105 mA 50

tREFC = 7.8µs IDD5A 6 6 mA 28, 50

Self refresh current: CKE d 0.2V Standard IDD6 44mA12

Low power (L) IDD6A 22mA12

Operating bank interleave read 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

IDD7 175 175 mA 23, 49

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256Mb: x4, x8, x16 DDR SDRAM

Electrical Specifications – DC and AC

Stresses greater than those listed in Table 1 may cause permanent damage to the device.

This is a stress rating only, and functional operation of the device at these or any other

conditions above those indicated in the operational sections of this specification is not

implied. Exposure to absolute maximum rating conditions for extended periods may

affect reliability.

Table 1: Absolute Maximum Ratings

Parameter Min Max Units

VDD supply voltage relative to VSS –1V 3.6V V

VDDQ supply voltage relative to VSS –1V 3.6V V

VREF and inputs voltage relative to VSS –1V 3.6V V

I/O pins voltage relative to VSS –0.5V VDDQ + 0.5V V

Storage temperature (plastic) –55 150 °C

Short circuit output current –50mA

Table 2: DC Electrical Characteristics and Operating Conditions (-5B)

Notes: 1–5 and 17 apply to the entire table; Notes appear on page 35; VDDQ = 2.6V ±0.1V, VDD = 2.6V ±0.1V

Parameter/Condition Symbol Min Max Units Notes

Supply voltage VDD 2.5 2.7 V 37, 42

I/O supply voltage VDDQ 2.5 2.7 V 37, 42, 45

I/O reference voltage VREF 0.49 × VDDQ 0.51 × VDDQ V7, 45

I/O termination voltage (system) VTT VREF - 0.04 VREF + 0.04 V 8, 45

Input high (logic 1) voltage VIH(DC) VREF + 0.15 VDD + 0.3 V 29

Input low (logic 0) voltage VIL(DC) –0.3 VREF - 0.15 V 29

Input leakage current:

Any input 0V d VIN d VDD, VREF pin 0V d VIN d 1.35V

(All other pins not under test = 0V)

II–2 2 µA

Output leakage current:

(DQ are disabled; 0Vd VOUT dVDDQ)

IOZ –5 5 µA

Full-drive option output

levels (x4, x8, x16):

High current (VOUT =

VDDQ - 0.373V, minimum

VREF

, minimum VTT)

IOH –16.8 – mA 38, 40

Low current (VOUT =

0.373V, maximum VREF

maximum VTT)

IOL 16.8 – mA

Reduced-drive option

output levels (Design

Revision F and K only):

High current (VOUT =

VDDQ - 0.373V, minimum

VREF

, minimum VTT)

IOHR –9 – mA 39, 40

Low current (VOUT =

0.373V, maximum VREF

maximum VTT)

IOLR 9–mA

Ambient operating

temperatures

Commercial TA070°C

Industrial TA–40 85 °C

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Electrical Specifications – DC and AC

Table 3: DC Electrical Characteristics and Operating Conditions (-6, -6T, -75E, -75Z, -75)

Notes: 1–5 and 17 apply to the entire table; Notes appear on page 35; VDDQ = 2.5V ±0.2V, VDD = 2.5V ±0.2V

Parameter/Condition Symbol Min Max Units Notes

Supply voltage VDD 2.3 2.7 V 37, 42

I/O supply voltage VDDQ 2.3 2.7 V 37, 42, 45

I/O reference voltage VREF 0.49 × VDDQ 0.51 × VDDQ V7, 45

I/O termination voltage (system) VTT VREF - 0.04 VREF + 0.04 V 8, 45

Input high (logic 1) voltage VIH(DC) VREF + 0.15 VDD + 0.3 V 29

Input low (logic 0) voltage VIL(DC) –0.3 VREF - 0.15 V 29

Input leakage current:

Any input 0V d VIN d VDD, VREF pin 0V d VIN d 1.35V

(All other pins not under test = 0V)

II–2 2 µA

Output leakage current:

(DQ are disabled; 0Vd VOUT dVDDQ)

IOZ –5 5 µA

Full-drive option output

levels (x4, x8, x16):

High current (VOUT =

VDDQ - 0.373V, minimum

VREF

, minimum VTT)

IOH –16.8 – mA 38, 40

Low current (VOUT =

0.373V, maximum VREF

maximum VTT)

IOL 16.8 – mA

Reduced-drive option

output levels (Design

Revision F and K only):

High current (VOUT =

VDDQ - 0.373V, minimum

VREF

, minimum VTT)

IOHR –9 – mA 39, 40

Low current (VOUT =

0.373V, maximum VREF

maximum VTT)

IOLR 9–mA

Ambient operating

temperatures

Commercial TA070°C

Industrial TA–40 85 °C

Table 4: AC Input Operating Conditions

Notes: 1–5 and 17 apply to the entire table; Notes appear on page 35;

0°C dTAd 70°C; VDDQ = 2.5V ±0.2V, VDD = 2.5V ±0.2V (VDDQ = 2.6V ±0.1V, VDD = 2.6V ±0.1V for -5B)

Parameter/Condition Symbol Min Max Units Notes

Input high (logic 1) voltage VIH(AC) VREF + 0.310 – V 15, 29, 41

Input low (logic 0) voltage VIL(AC) –V

REF - 0.310 V 15, 29, 41

I/O reference voltage VREF(AC) 0.49 × VDDQ 0.51 × VDDQ V7

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256Mb: x4, x8, x16 DDR SDRAM

Electrical Specifications – DC and AC

Figure 1: Input Voltage Waveform

Notes: 1. VOH,min with test load is 1.927V.

2. VOL,max with test load is 0.373V.

3. Numbers in diagram reflect nominal values utilizing circuit below for all devices other than

-5B.

0.940V

1.100V

1.200V

1.225V

1.250V

1.275V

1.300V

1.400V

1.560V

VIL(AC)

VIL(DC)

VREF - AC noise

VREF - DC error

VREF + DC error

VREF + AC noise

Receiver

Transmitter

VIH(DC)

VIH(AC)

VOH,min (1.670V1for SSTL_2 termination)

VIN(AC) - provides margin

between VOL,max

and VIL(AC)

VSSQ

VDDQ,min (2.3V)

VOL,max (0.83V2 for SSTL_2

termination)

System noise margin (power/ground,

crosstalk, signal integrity attenuation)

Reference

point

25Ω

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256Mb: x4, x8, x16 DDR SDRAM

Electrical Specifications – DC and AC

Figure 2: SSTL_2 Clock Input

Notes: 1. CK or CK# may not be more positive than VDDQ + 0.3V or more negative than VSS - 0.3V.

2. This provides a minimum of 1.15V to a maximum of 1.35V and is always half of VDDQ.

3. CK and CK# must cross in this region.

4. CK and CK# must meet at least VID(DC),min when static and is centered around VMP(DC).

5. CK and CK# must have a minimum 700mV peak-to-peak swing.

6. For AC operation, all DC clock requirements must also be satisfied.

7. Numbers in diagram reflect nominal values for all devices other than -5B.

Table 5: Clock Input Operating Conditions

Notes: 1–5, 16, 17, and 31 apply to the entire table; Notes appear on page 35;

0°C dTAd 70°C; VDDQ = 2.5V ±0.2V, VDD = 2.5V ±0.2V (VDDQ = 2.6V ±0.1V, VDD = 2.6V ±0.1V for -5B)

Parameter/Condition Symbol Min Max Units Notes

Clock input mid-point voltage: CK and CK# VMP(DC) 1.15 1.35 V 7, 10

Clock input voltage level: CK and CK# VIN(DC) –0.3 VDDQ + 0.3 V 7

Clock input differential voltage: CK and CK# VID(DC) 0.36 VDDQ + 0.6 V 7, 9

Clock input differential voltage: CK and CK# VID(AC) 0.7 VDDQ + 0.6 V 9

Clock input crossing point voltage: CK and CK# VIX(AC) 0.5 × VDDQ - 0.2 0.5 × VDDQ + 0.2 V 10

CK#

2.80V Maximum clock level

Minimum clock level

–0.30V

1.25V

1.45V

1.05V

ID(AC)5

ID(DC)4

MP(DC)2

IX(AC)3

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256Mb: x4, x8, x16 DDR SDRAM

Electrical Specifications – DC and AC

Table 6: Capacitance (x4, x8 TSOP)

Note: 14 applies to the entire table; Notes appear on page 35

Parameter Symbol Min Max Units Notes

Delta input/output capacitance: DQ[3:0] (x4), DQ[7:0] (x8) DCIO –0.50pF 25

Delta input capacitance: Command and address DCI1 –0.50pF 30

Delta input capacitance: CK, CK# DCI2 –0.25pF 30

Input/output capacitance: DQ, DQS, DM CIO 4.0 5.0 pF

Input capacitance: Command and address CI1 2.0 3.0 pF

Input capacitance: CK, CK# CI2 2.0 3.0 pF

Input capacitance: CKE CI3 2.0 3.0 pF

Table 7: Capacitance (x4, x8 FBGA)

Note: 14 applies to the entire table; Notes appear on page 35

Parameter Symbol Min Max Units Notes

Delta input/output capacitance: DQ, DQS, DM DCIO –0.50pF 25

Delta input capacitance: Command and address DCI1 –0.50pF 30

Delta input capacitance: CK, CK# DCI2 –0.25pF 30

Input/output capacitance: DQ, DQS, DM CIO 3.5 4.5 pF

Input capacitance: Command and address CI1 1.5 2.5 pF

Input capacitance: CK, CK# CI2 1.5 2.5 pF

Input capacitance: CKE CI3 1.5 2.5 pF

Table 8: Capacitance (x16 TSOP)

Note: 14 applies to the entire table; Notes appear on page 35

Parameter Symbol Min Max Units Notes

Delta input/output capacitance: DQ[7:0], LDQS, LDM DCIOL –0.50pF 25

Delta input/output capacitance: DQ[15:8], UDQS, UDM DCIOU –0.50pF 25

Delta input capacitance: Command and address DCI1 –0.50pF 30

Delta input capacitance: CK, CK# DCI2 –0.25pF 30

Input/output capacitance: DQ, LDQS, UDQS, LDM, UDM CIO 4.0 5.0 pF

Input capacitance: Command and address CI1 2.0 3.0 pF

Input capacitance: CK, CK# CI2 2.0 3.0 pF

Input capacitance: CKE CI3 2.0 3.0 pF

Table 9: Capacitance (x16 FBGA)

Note: 14 applies to the entire table; Notes appear on page 35

Parameter Symbol Min Max Units Notes

Delta input/output capacitance: DQ[7:0], LDQS, LDM DCIOL –0.50pF 25

Delta input/output capacitance: DQ[15:8], UDQS, UDM DCIOU –0.50pF 25

Delta input capacitance: Command and address DCI1 –0.50pF 30

Delta input capacitance: CK, CK# DCI2 –0.25pF 30

Input/output capacitance: DQ, LDQS, UDQS, LDM, UDM CIO 3.5 4.5 pF

Input capacitance: Command and address CI1 1.5 2.5 pF

Input capacitance: CK, CK# CI2 1.5 2.5 pF

Input capacitance: CKE CI3 1.5 2.5 pF

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256Mb: x4, x8, x16 DDR SDRAM

Electrical Specifications – DC and AC

Table 10: Electrical Characteristics and Recommended AC Operating Conditions (-5B)

Notes 1–6, 16–18, and 34 apply to the entire table; Notes appear on page 35;

0°C dTAd 70°C; VDDQ = 2.6V ±0.1V, VDD = 2.6V ±0.1V

AC Characteristics -5B

Units NotesParameter Symbol Min Max

Access window of DQ from CK/CK# tAC –0.70 0.70 ns

CK high-level width tCH 0.45 0.55 tCK 31

Clock cycle time CL = 3 tCK (3) 5 7.5 ns 52

CL = 2.5 tCK (2.5) 6 13 ns 46, 52

CL = 2 tCK (2) 7.5 13 ns 46, 52

CK low-level width tCL 0.45 0.55 tCK 31

DQ and DM input hold time relative to DQS tDH 0.40 – ns 27, 32

DQ and DM input pulse width (for each input) tDIPW 1.75 – ns 32

Access window of DQS from CK/CK# tDQSCK –0.60 0.60 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 – 0.40 ns 26, 27

WRITE command to first DQS latching transition tDQSS 0.72 1.28 tCK

DQ and DM input setup time relative to DQS tDS 0.40 – ns 27, 32

DQS falling edge from CK rising – hold time tDSH 0.2 – tCK

DQS falling edge to CK rising – setup time tDSS 0.2 – tCK

Half-clock period tHP tCH,tCL – ns 35

Data-out High-Z window from CK/CK# tHZ – 0.70 ns 19, 43

Address and control input hold time (slew rate t0.5 V/ns) tIHF0.60 – ns 15

Address and control input pulse width (for each input) tIPW 2.2 – ns

Address and control input setup time (fast slew rate) tISF0.60 – ns 15

Address and control input setup time (slow slew rate) tISS0.70 – ns

Data-out Low-Z window from CK/CK# tLZ –0.70 – ns 19, 43

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 26, 27

Data hold skew factor tQHS – 0.50 ns

ACTIVE-to-READ with auto precharge command tRAP 15 – ns

ACTIVE-to-PRECHARGE command tRAS 40 70,000 ns 36

ACTIVE-to-ACTIVE/AUTO REFRESH command period tRC 55 – ns 55

ACTIVE-to-READ or WRITE delay tRCD 15 – ns

REFRESH-to-REFRESH command interval tREFC – 70.3 µs 24

Average periodic refresh interval tREFI – 7.8 µs 24

AUTO REFRESH command period tRFC 70 – ns 50

PRECHARGE command period tRP 15 – ns

DQS read preamble tRPRE 0.9 1.1 tCK 44

DQS read postamble tRPST 0.4 0.6 tCK 44

ACTIVE bank ato ACTIVE bank bcommand tRRD 10 – ns

Terminating voltage delay to VDD tVTD 0 – ns

DQS write preamble tWPRE 0.25 – tCK

DQS write preamble setup time tWPRES 0 – ns 21, 22

DQS write postamble tWPST 0.4 0.6 tCK 20

Write recovery time tWR 15 – ns

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256Mb: x4, x8, x16 DDR SDRAM

Electrical Specifications – DC and AC

Internal WRITE-to-READ command delay tWTR 2 – tCK

Exit SELF REFRESH-to-non-READ command tXSNR 70 – ns

Exit SELF REFRESH-to-READ command tXSRD 200 – tCK

Data valid output window n/a tQH - tDQSQ ns 26

Table 10: Electrical Characteristics and Recommended AC Operating Conditions (-5B) (continued)

Notes 1–6, 16–18, and 34 apply to the entire table; Notes appear on page 35;

0°C dTAd 70°C; VDDQ = 2.6V ±0.1V, VDD = 2.6V ±0.1V

AC Characteristics -5B

Units NotesParameter Symbol Min Max

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256Mb: x4, x8, x16 DDR SDRAM

Electrical Specifications – DC and AC

Table 11: Electrical Characteristics and Recommended AC Operating Conditions (-6)

Notes: 1–6, 16–18, 34 apply to the entire table; Notes appear on page 35;

0°C dTAd 70°C; VDDQ = 2.5V ±0.2V, VDD = 2.5V ±0.2V

AC Characteristics -6 (FBGA)

Units NotesParameter Symbol Min Max

Access window of DQ from CK/CK# tAC –0.70 0.70 ns

CK high-level width tCH 0.45 0.55 tCK 31

Clock cycle time CL = 2.5 tCK (2.5) 6 13 ns 46, 52

CL = 2 tCK (2) 7.5 13 ns 46, 52

CK low-level width tCL 0.45 0.55 tCK 31

DQ and DM input hold time relative to DQS tDH 0.45 – ns 27, 32

DQ and DM input pulse width (for each input) tDIPW 1.75 – ns 32

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 26, 27

WRITE command to first DQS latching transition tDQSS 0.75 1.25 tCK

DQ and DM input setup time relative to DQS tDS 0.45 – ns 27, 32

DQS falling edge from CK rising - hold time tDSH 0.2 – tCK

DQS falling edge to CK rising - setup time tDSS 0.2 – tCK

Half-clock period tHP tCH, tCL – ns 35

Data-out High-Z window from CK/CK# tHZ – 0.7 ns 19, 43

Address and control input hold time (fast slew rate) tIHF0.75 – ns

Address and control input hold time (slow slew rate) tIHS0.8 – ns 15

Address and control input pulse width (for each input) tIPW 2.2 – ns

Address and control input setup time (fast slew rate) tISF0.75 – ns

Address and control input setup time (slow slew rate) tISS0.8 – ns 15

Data-out Low-Z window from CK/CK# tLZ –0.7 – ns 19, 43

LOAD MODE REGISTER command cycle time tMRD 12 – ns

DQ-DQS hold, DQS to first DQ to go non-valid, per access tQH tHP -tQHS – ns 26, 27

Data hold skew factor tQHS – 0.50 ns

ACTIVE-to-READ with auto precharge command tRAP 15 – ns

ACTIVE-to-PRECHARGE command tRAS 42 70,000 ns 36, 54

ACTIVE-to-ACTIVE/AUTO REFRESH command period tRC 60 – ns 55

ACTIVE-to-READ or WRITE delay tRCD 15 – ns

REFRESH-to-REFRESH command interval tREFC – 70.3 µs 24

Average periodic refresh interval tREFI – 7.8 µs 24

AUTO REFRESH command period tRFC 72 – ns 50

PRECHARGE command period tRP 15 – ns

DQS read preamble tRPRE 0.9 1.1 tCK 44

DQS read postamble tRPST 0.4 0.6 tCK 44

ACTIVE bank a to ACTIVE bank bcommand tRRD 12 – ns

Terminating voltage delay to VSS tVTD 0 – ns

DQS write preamble tWPRE 0.25 – tCK

DQS write preamble setup time tWPRES 0 – ns 21, 22

DQS write postamble tWPST 0.4 0.6 tCK 20

Write recovery time tWR 15 – ns

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256Mb: x4, x8, x16 DDR SDRAM

Electrical Specifications – DC and AC

Internal WRITE-to-READ command delay tWTR 1 – tCK

Exit SELF REFRESH-to-non-READ command tXSNR 75 – ns

Exit SELF REFRESH-to-READ command tXSRD 200 – tCK

Data valid output window n/a tQH - tDQSQ ns 26

Table 11: Electrical Characteristics and Recommended AC Operating Conditions (-6) (continued)

Notes: 1–6, 16–18, 34 apply to the entire table; Notes appear on page 35;

0°C dTAd 70°C; VDDQ = 2.5V ±0.2V, VDD = 2.5V ±0.2V

AC Characteristics -6 (FBGA)

Units NotesParameter Symbol Min Max

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Electrical Specifications – DC and AC

Table 12: Electrical Characteristics and Recommended AC Operating Conditions (-6T)

Notes: 1–6, 16–18, and 34 apply to the entire table; Notes appear on page 35;

0°C dTAd 70°C; VDDQ = 2.5V ±0.2V, VDD = 2.5V ±0.2V

AC Characteristics -6T (TSOP)

Units NotesParameter Symbol Min Max

Access window of DQ from CK/CK# tAC –0.70 0.70 ns

CK high-level width tCH 0.45 0.55 tCK 31

Clock cycle time CL = 2.5 tCK (2.5) 6 13 ns 46, 52

CL = 2 tCK (2) 7.5 13 ns 46, 52

CK low-level width tCL 0.45 0.55 tCK 31

DQ and DM input hold time relative to DQS tDH 0.45 – ns 27, 32

DQ and DM input pulse width (for each input) tDIPW 1.75 – ns 32

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 – 0.45 ns 26, 27

WRITE command to first DQS latching transition tDQSS 0.75 1.25 tCK

DQ and DM input setup time relative to DQS tDS 0.45 – ns 27, 32

DQS falling edge from CK rising - hold time tDSH 0.2 – tCK

DQS falling edge to CK rising - setup time tDSS 0.2 – tCK

Half-clock period tHP tCH,

tCL

–ns35

Data-out High-Z window from CK/CK# tHZ – 0.7 ns 19, 43

Address and control input hold time (fast slew rate) tIHF0.75 – ns

Address and control input hold time (slow slew rate) tIHS0.8 – ns 15

Address and control input pulse width (for each input) tIPW 2.2 – ns

Address and control input setup time (fast slew rate) tISF0.75 – ns

Address and control input setup time (slow slew rate) tISS0.8 – ns 15

Data-out Low-Z window from CK/CK# tLZ –0.7 – ns 19, 43

LOAD MODE REGISTER command cycle time tMRD 12 – ns

DQ-DQS hold, DQS to first DQ to go non-valid, per access tQH tHP -tQHS – ns 26, 27

Data hold skew factor tQHS – 0.55 ns

ACTIVE-to-READ with auto precharge command tRAP 15 – ns

ACTIVE-to-PRECHARGE command tRAS 42 70,000 ns 36, 54

ACTIVE-to-ACTIVE/AUTO REFRESH command period tRC 60 – ns 55

ACTIVE-to-READ or WRITE delay tRCD 15 – ns

REFRESH-to-REFRESH command interval tREFC – 70.3 µs 24

Average periodic refresh interval tREFI – 7.8 µs 24

AUTO REFRESH command period tRFC 72 – ns 50

PRECHARGE command period tRP 15 – ns

DQS read preamble tRPRE 0.9 1.1 tCK 44

DQS read postamble tRPST 0.4 0.6 tCK 44

ACTIVE bank a to ACTIVE bank bcommand tRRD 12 – ns

Terminating voltage delay to VSS tVTD 0 – ns

DQS write preamble tWPRE 0.25 – tCK

DQS write preamble setup time tWPRES 0 – ns 21, 22

DQS write postamble tWPST 0.4 0.6 tCK 20

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256Mb: x4, x8, x16 DDR SDRAM

Electrical Specifications – DC and AC

Write recovery time tWR 15 – ns

Internal WRITE-to-READ command delay tWTR 1 – tCK

Exit SELF REFRESH-to-non-READ command tXSNR 75 – ns

Exit SELF REFRESH-to-READ command tXSRD 200 – tCK

Data valid output window n/a tQH - tDQSQ ns 26

Table 12: Electrical Characteristics and Recommended AC Operating Conditions (-6T) (continued)

Notes: 1–6, 16–18, and 34 apply to the entire table; Notes appear on page 35;

0°C dTAd 70°C; VDDQ = 2.5V ±0.2V, VDD = 2.5V ±0.2V

AC Characteristics -6T (TSOP)

Units NotesParameter Symbol Min Max

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Electrical Specifications – DC and AC

Table 13: Electrical Characteristics and Recommended AC Operating Conditions (-75E)

Notes: 1–6, 16–18, 34 apply to the entire table; Notes appear on page 35;

0°C dTAd 70°C; VDDQ = 2.5V ±0.2V, VDD = 2.5V ±0.2V

AC Characteristics -75E

Units NotesParameter Symbol Min Max

Access window of DQ from CK/CK# tAC –0.75 0.75 ns

CK high-level width tCH 0.45 0.55 tCK 31

Clock cycle time CL = 2.5 tCK (2.5) 7.5 13 ns 46, 52

CL = 2 tCK (2) 7.5 13 ns 46, 52

CK low-level width tCL 0.45 0.55 tCK 31

DQ and DM input hold time relative to DQS tDH 0.5 – ns 27, 32

DQ and DM input pulse width (for each input) tDIPW 1.75 – ns 32

Access window of DQS from CK/CK# tDQSCK –0.75 0.75 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 – 0.5 ns 26, 27

WRITE command to first DQS latching transition tDQSS 0.75 1.25 tCK

DQ and DM input setup time relative to DQS tDS 0.5 – ns 27, 32

DQS falling edge from CK rising - hold time tDSH 0.2 – tCK

DQS falling edge to CK rising - setup time tDSS 0.2 – tCK

Half-clock period tHP tCH,

tCL

–ns35

Data-out High-Z window from CK/CK# tHZ – 0.75 ns 19, 43

Address and control input hold time (fast slew rate) tIHF0.90 – ns

Address and control input hold time (slow slew rate) tIHS1–ns15

Address and control input pulse width (for each input) tIPW 2.2 – ns

Address and control input setup time (fast slew rate) tISF0.90 – ns

Address and control input setup time (slow slew rate) tISS1–ns15

Data-out Low-Z window from CK/CK# tLZ –0.75 – ns 19, 43

LOAD MODE REGISTER command cycle time tMRD 15 – ns

DQ-DQS hold, DQS to first DQ to go non-valid, per access tQH tHP -tQHS – ns 26, 27

Data hold skew factor tQHS – 0.75 ns

ACTIVE-to-READ with auto precharge command tRAP 15 – ns

ACTIVE-to-PRECHARGE command tRAS 40 120,000 ns 36, 54

ACTIVE-to-ACTIVE/AUTO REFRESH command period tRC 60 – ns 55

ACTIVE-to-READ or WRITE delay tRCD 15 – ns

REFRESH-to-REFRESH command interval tREFC – 70.3 µs 24

Average periodic refresh interval tREFI – 7.8 µs 24

AUTO REFRESH command period tRFC 75 – ns 50

PRECHARGE command period tRP 15 – ns

DQS read preamble tRPRE 0.9 1.1 tCK 44

DQS read postamble tRPST 0.4 0.6 tCK 44

ACTIVE bank a to ACTIVE bank bcommand tRRD 15 – ns

Terminating voltage delay to VSS tVTD 0 – ns

DQS write preamble tWPRE 0.25 – tCK

DQS write preamble setup time tWPRES 0 – ns 21, 22

DQS write postamble tWPST 0.4 0.6 tCK 20

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Electrical Specifications – DC and AC

Write recovery time tWR 15 – ns

Internal WRITE-to-READ command delay tWTR 1 – tCK

Exit SELF REFRESH-to-non-READ command tXSNR 75 – ns

Exit SELF REFRESH-to-READ command tXSRD 200 – tCK

Data valid output window n/a tQH - tDQSQ ns 26

Table 13: Electrical Characteristics and Recommended AC Operating Conditions (-75E) (continued)

Notes: 1–6, 16–18, 34 apply to the entire table; Notes appear on page 35;

0°C dTAd 70°C; VDDQ = 2.5V ±0.2V, VDD = 2.5V ±0.2V

AC Characteristics -75E

Units NotesParameter Symbol Min Max

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Electrical Specifications – DC and AC

Table 14: Electrical Characteristics and Recommended AC Operating Conditions (-75Z)

Notes: 1–6, 16–18, 34 apply to the entire table; Notes appear on page 35;

0°C dTAd 70°C; VDDQ = 2.5V ±0.2V, VDD = 2.5V ±0.2V

AC Characteristics -75Z

Units NotesParameter Symbol Min Max

Access window of DQ from CK/CK# tAC –0.75 0.75 ns

CK high-level width tCH 0.45 0.55 tCK 31

Clock cycle time CL = 2.5 tCK (2.5) 7.5 13 ns 46

CL = 2 tCK (2) 7.5 13 ns 46

CK low-level width tCL 0.45 0.55 tCK 31

DQ and DM input hold time relative to DQS tDH 0.5 – ns 27, 32

DQ and DM input pulse width (for each input) tDIPW 1.75 – ns 32

Access window of DQS from CK/CK# tDQSCK –0.75 0.75 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 – 0.5 ns 26, 27

WRITE command-to-first DQS latching transition tDQSS 0.75 1.25 tCK

DQ and DM input setup time relative to DQS tDS 0.5 – ns 27, 32

DQS falling edge from CK rising – hold time tDSH 0.2 – tCK

DQS falling edge to CK rising – setup time tDSS 0.2 – tCK

Half-clock period tHP tCH,tCL – ns 35

Data-out High-Z window from CK/CK# tHZ – 0.75 ns 19, 43

Address and control input hold time (fast slew rate) tIHF0.90 – ns

Address and control input hold time (slow slew rate) tIHS1–ns15

Address and control input pulse width (for each input) tIPW 2.2 – ns

Address and control input setup time (fast slew rate) tISF0.90 – ns

Address and control input setup time (slow slew rate) tISS1–ns15

Data-out Low-Z window from CK/CK# tLZ –0.75 – ns 19, 43

LOAD MODE REGISTER command cycle time tMRD 15 – ns

DQ–DQS hold, DQS to first DQ to go non-valid, per access tQH tHP -tQHS – ns 26, 27

Data hold skew factor tQHS – 0.75 ns

ACTIVE-to-READ with auto precharge command tRAP 20 – ns

ACTIVE-to-PRECHARGE command tRAS 40 120,000 ns 36

ACTIVE-to-ACTIVE/AUTO REFRESH command period tRC 65 – ns 55

ACTIVE-to-READ or WRITE delay tRCD 20 – ns

REFRESH-to-REFRESH command interval tREFC – 70.3 µs 24

Average periodic refresh interval tREFI – 7.8 µs 24

AUTO REFRESH command period tRFC 75 – ns 50

PRECHARGE command period tRP 20 – ns

DQS read preamble tRPRE 0.9 1.1 tCK 44

DQS read postamble tRPST 0.4 0.6 tCK 44

ACTIVE bank a to ACTIVE bank bcommand tRRD 15 – ns

Terminating voltage delay to VDD tVTD 0 – ns

DQS write preamble tWPRE 0.25 – tCK

DQS write preamble setup time tWPRES 0 – ns 21, 22

DQS write postamble tWPST 0.4 0.6 tCK 20

Write recovery time tWR 15 – ns

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Electrical Specifications – DC and AC

Internal WRITE-to-READ command delay tWTR 1 – tCK

Exit SELF REFRESH-to-non-READ command tXSNR 75 – ns

Exit SELF REFRESH-to-READ command tXSRD 200 – tCK

Data valid output window n/a tQH - tDQSQ ns 26

Table 14: Electrical Characteristics and Recommended AC Operating Conditions (-75Z) (continued)

Notes: 1–6, 16–18, 34 apply to the entire table; Notes appear on page 35;

0°C dTAd 70°C; VDDQ = 2.5V ±0.2V, VDD = 2.5V ±0.2V

AC Characteristics -75Z

Units NotesParameter Symbol Min Max

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Electrical Specifications – DC and AC

Table 15: Electrical Characteristics and Recommended AC Operating Conditions (-75)

Notes: 1–6, 16–18, and 34 apply to the entire table; Notes appear on page 35;

0°C dTAd 70°C; VDDQ = 2.5V ±0.2V, VDD = 2.5V ±0.2V

AC Characteristics -75

Units NotesParameter Symbol Min Max

Access window of DQ from CK/CK# tAC –0.75 0.75 ns

CK high-level width tCH 0.45 0.55 tCK 31

Clock cycle time CL = 2.5 tCK (2.5) 7.5 13 ns 46

CL = 2 tCK (2) 10 13 ns 46

CK low-level width tCL 0.45 0.55 tCK 31

DQ and DM input hold time relative to DQS tDH 0.5 – ns 27, 32

DQ and DM input pulse width (for each input) tDIPW 1.75 – ns 32

Access window of DQS from CK/CK# tDQSCK –0.75 0.75 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 – 0.5 ns 26, 27

WRITE command-to-first DQS latching transition tDQSS 0.75 1.25 tCK

DQ and DM input setup time relative to DQS tDS 0.5 – ns 27, 32

DQS falling edge from CK rising – hold time tDSH 0.2 – tCK

DQS falling edge to CK rising – setup time tDSS 0.2 – tCK

Half-clock period tHP tCH,tCL – ns 35

Data-out High-Z window from CK/CK# tHZ – 0.75 ns 19, 43

Address and control input hold time (fast slew rate) tIHF0.90 – ns

Address and control input hold time (slow slew rate) tIHS1–ns15

Address and control input pulse width (for each input) tIPW 2.2 – ns

Address and control input setup time (fast slew rate) tISF0.90 – ns

Address and control input setup time (slow slew rate) tISS1–ns15

Data-out Low-Z window from CK/CK# tLZ –0.75 – ns 19, 43

LOAD MODE REGISTER command cycle time tMRD 15 – ns

DQ–DQS hold, DQS to first DQ to go non-valid, per access tQH tHP -tQHS – ns 26, 27

Data hold skew factor tQHS – 0.75 ns

ACTIVE-to-READ with auto precharge command tRAP 20 – ns

ACTIVE-to-PRECHARGE command tRAS 40 120,000 ns 36

ACTIVE-to-ACTIVE/AUTO REFRESH command period tRC 65 – ns 55

ACTIVE-to-READ or WRITE delay tRCD 20 – ns

REFRESH-to-REFRESH command interval tREFC – 70.3 µs 24

Average periodic refresh interval tREFI – 7.8 µs 24

AUTO REFRESH command period trFC 75 – ns 50

PRECHARGE command period tRP 20 – ns

DQS read preamble tRPRE 0.9 1.1 tCK 44

DQS read postamble tRPST 0.4 0.6 tCK 44

ACTIVE bank a to ACTIVE bank b command tRRD 15 – ns

Terminating voltage delay to VDD tVTD 0 – ns

DQS write preamble tWPRE 0.25 – tCK

DQS write preamble setup time tWPRES 0 – ns 21, 22

DQS write postamble tWPST 0.4 0.6 tCK 20

Write recovery time tWR 15 – ns

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Electrical Specifications – DC and AC

Internal WRITE-to-READ command delay tWTR 1 – tCK

Exit SELF REFRESH-to-non-READ command tXSNR 75 – ns

Exit SELF REFRESH-to-READ command tXSRD 200 – tCK

Data valid output window n/a tQH - tDQSQ ns 26

Table 16: Input Slew Rate Derating Values for Addresses and Commands

Note: 15 applies to the entire table; Notes appear on page 35;

0°C dTAd 70°C; VDDQ = 2.5V ±0.2V, VDD = 2.5V ±0.2V

Speed Slew Rate tIS tIH Units

-75Z/-75E 0.500 V/ns 1.00 1 ns

-75Z/-75E 0.400 V/ns 1.05 1 ns

-75Z/-75E 0.300 V/ns 1.10 1 ns

Table 17: Input Slew Rate Derating Values for DQ, DQS, and DM

Note: 32 applies to the entire table; Notes appear on page 35;

0°C dTAd 70°C; VDDQ = 2.5V ±0.2V, VDD = 2.5V ±0.2V

Speed Slew Rate tDS tDH Units

-75Z/-75E 0.500 V/ns 0.50 0.50 ns

-75Z/-75E 0.400 V/ns 0.55 0.55 ns

-75Z/-75E 0.300 V/ns 0.60 0.60 ns

Table 15: Electrical Characteristics and Recommended AC Operating Conditions (-75) (continued)

Notes: 1–6, 16–18, and 34 apply to the entire table; Notes appear on page 35;

0°C dTAd 70°C; VDDQ = 2.5V ±0.2V, VDD = 2.5V ±0.2V

AC Characteristics -75

Units NotesParameter Symbol Min Max

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Electrical Specifications – DC and AC

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 the

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 (that

is, 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. All speed grades are not offered on all densities. Refer to page 1 for availability.

7. 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% 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.

8. VTT is not applied directly to the device. VTT is a system supply for signal termination

resistors, it is expected to be set equal to VREF

, and it must track variations in the DC

level of VREF

9. VID is the magnitude of the difference between the input level on CK and the input

level on CK#.

10. The value of VIX and VMP is expected to equal VDDQ/2 of the transmitting device and

must track variations in the DC level of the same.

11. 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, -6/-6T/-75; and CL = 2,

-75E/-75Z speeds with the outputs open.

12. Enables on-chip refresh and address counters.

13. IDD specifications are tested after the device is properly initialized and is averaged at

the defined cycle rate.

14. This parameter is sampled. VDD = 2.5V ±0.2V, VDDQ = 2.5V ±0.2V, VREF =V

SS,

f=100MHz, T

A=25°C, V

OUT(DC) =V

DDQ/2, VOUT (peak-to-peak) = 0.2V. DM input is

grouped with I/O pins, reflecting the fact that they are matched in loading.

15. For slew rates less than 1 V/ns and greater than or equal to 0.5 V/ns. If the slew rate is

less than 0.5 V/ns, timing must be derated: tIS has an additional 50ps per each

100 mV/ns reduction in slew rate from the 500 mV/ns. tIH has 0ps added, that is, it

remains constant. 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 0.5 V/ns.

Output

(VOUT)

Reference

point

50:

VTT

30pF

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Electrical Specifications – DC and AC

16. 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

17. Inputs are not recognized as valid until VREF stabilizes. Once initialized, including self

refresh mode, VREF must be powered within specified range. Exception: during the

period before VREF stabilizes, CKE < 0.3 × VDD is recognized as LOW.

18. The output timing reference level, as measured at the timing reference point (indi-

cated in Note 3), is VTT

19. 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 (High-Z) or begins driving (Low-Z).

20. The intent of the “Don’t Care” state after completion of the postamble is 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. That is, if

DQS transitions HIGH (above VIH(DC)min) then it must not transition LOW (below

VIH(DC) prior to tDQSH [MIN]).

21. This is not a device limit. The device will operate with a negative value, but system

performance could be degraded due to bus turnaround.

22. 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.

23. MIN (tRC or tRFC) for IDD measurements is the smallest multiple of tCK that meets

the minimum absolute value for the respective parameter. tRAS (MAX) for IDD mea-

surements is the largest multiple of tCK that meets the maximum absolute value for

tRAS.

24. 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 8 REFRESH cycles is not

allowed.

25. The I/O capacitance per DQS and DQ byte/group will not differ by more than this

maximum amount for any given device.

26. 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 propor-

tion 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 functionality is

uncertain when operating beyond a 45/55 ratio. The data valid window derating

curves are provided in Figure 3 on page 37 for duty cycles ranging between 50/50 and

45/55.

27. Referenced to each output group: x4 = DQS with DQ[3:0]; x8 = DQS with DQ[7:0];

x16 = LDQS with DQ[7:0] and UDQS with DQ[15:8].

28. This limit is actually a nominal value and does not result in a fail value. CKE is HIGH

during the REFRESH command period (tRFC [MIN]), else CKE is LOW (that is, during

standby).

29. To maintain a valid level, the transitioning edge of the input must:

29a. Sustain a constant slew rate from the current AC level through to the target AC

level, VIL(AC) or VIH(AC).

29b. Reach at least the target AC level.

29c. After the AC target level is reached, continue to maintain at least the target DC

level, VIL(DC) or VIH(DC).

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Electrical Specifications – DC and AC

30. The input capacitance per pin group will not differ by more than this maximum

amount for any given device.

31. CK and CK# input slew rate must be t1V/ns (t2 V/ns if measured differentially).

Figure 3: Derating Data Valid Window (tQH – tDQSQ)

32. DQ and DM input slew rates must not deviate from DQS by more than 10%. 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 100 mV/ns reduction in slew rate. For -5B, -6, and

-6T speed grades, the slew rate must be t0.5 V/ns. If the slew rate exceeds 4 V/ns,

functionality is uncertain.

33. VDD must not vary more than 4% if CKE is not active while any bank is active.

34. The clock is allowed up to ±150ps of jitter. Each timing parameter is allowed to vary by

the same amount.

35. tHP (MIN) is the lesser of tCL (MIN) and tCH (MIN) actually applied to the device CK

and CK# inputs, collectively, during bank active.

36. 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.

37. 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) mini-

mum.

38. Normal output drive curves:

38a. The full driver pull-down current variation from MIN to MAX process; tempera-

ture and voltage will lie within the outer bounding lines of the V-I curve of

Figure 4 on page 38.

38b. The driver pull-down current variation, within nominal voltage and temperature

limits, is expected, but not guaranteed, to lie within the inner bounding lines of

the V-I curve of Figure 4 on page 38.

3.0ns

2.5ns

2.0ns

1.5ns

1.0ns

50/50 49/51 48/53 46/54 47/53 45/55

-6T @ tCK = 7.5ns

-75E / -75 @ tCK = 7.5ns

-6 @ tCK = 6ns

-6T @ tCK = 6ns

-5B @ tCK = 5ns

1.48 1.45 1.43 1.40 1.38 1.35

2.75

2.60 2.56 2.53

2.45 2.41 2.38

2.68

2.35 2.31 2.28

2.13

2.20 2.16

2.43

2.10 2.07 2.04

1.89 1.86 1.83 1.80

1.98 1.95

2.00 1.97 1.94 1.91 1.88

1.73 1.70

1.82 1.79

1.58 1.55

Clock Dut

cle

Data Valid Window

2.71

2.46

1.53

2.64

2.39

1.92

1.76

1.85

1.60

1.50

2.49

2.50

2.24

2.01

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Electrical Specifications – DC and AC

38c. The full driver pull-up current variation from MIN to MAX process; temperature

and voltage will lie within the outer bounding lines of the V-I curve of Figure 5 on

page 38.

38d. The driver pull-up current variation within nominal limits of voltage and temper-

ature is expected, but not guaranteed, to lie within the inner bounding lines of the

V-I curve of Figure 5 on page 38.

38e. The full ratio variation of MAX to MIN pull-up and pull-down current should be

between 0.71 and 1.4 for drain-to-source voltages from 0.1V to 1.0V at the same

voltage and temperature.

38f. The full ratio variation of the nominal pull-up to pull-down current should be

unity ±10% for device drain-to-source voltages from 0.1V to 1.0V.

Figure 4: Full Drive Pull-Down Characteristics

Figure 5: Full Drive Pull-Up Characteristics

39. Reduced output drive curves:

39a. The full driver pull-down current variation from MIN to MAX process; tempera-

ture and voltage will lie within the outer bounding lines of the V-I curve of

Figure 6 on page 39.

39b. The driver pull-down current variation, within nominal voltage and temperature

limits, is expected, but not guaranteed, to lie within the inner bounding lines of

the V-I curve of Figure 6 on page 39.

39c. The full driver pull-up current variation from MIN to MAX process; temperature

and voltage will lie within the outer bounding lines of the V-I curve of Figure 7.

100

120

140

160

0.0 0.5 1.0 1.5 2.0 2.5

OUT

(mA)

OUT

(V)

-200

-180

-160

-140

-120

-100

-80

-60

-40

-20

0.0 0.5 1.0 1.5 2.0 2.5

OUT

(mA)

DDQ

- V

OUT

(V)

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256Mb: x4, x8, x16 DDR SDRAM

Electrical Specifications – DC and AC

39d. The driver pull-up current variation, within nominal voltage and temperature

limits, is expected, but not guaranteed, to lie within the inner bounding lines of

the V-I curve of Figure 7 on page 39.

39e. The full ratio variation of the MAX-to-MIN 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 at

the same voltage and temperature.

39f. The full ratio variation of the nominal pull-up to pull-down current should be

unity ±10%, for device drain-to-source voltages from 0.1V to 1.0V.

Figure 6: Reduced Drive Pull-Down Characteristics

Figure 7: Reduced Drive Pull-Up Characteristics

40. 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 pro-

vide significantly different voltage values.

41. VIH overshoot: VIH,max =V

DDQ+1.5V for a pulse width d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 d3ns, and the pulse width can not be greater than 1/3 of the cycle rate.

42. VDD and VDDQ must track each other.

43. tHZ (MAX) will prevail over tDQSCK (MAX) + tRPST (MAX) condition. tLZ (MIN) will

prevail over tDQSCK (MIN) + tRPRE (MAX) condition.

0.00.51.01.5

2.0 2.5

OUT

(mA)

OUT

(V)

-80

-70

-60

-50

-40

-30

-20

-10

0.0 0.5 1.0 1.5 2.0 2.5

OUT

(mA)

DDQ

- V

OUT

(V)

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256Mb: x4, x8, x16 DDR SDRAM

Electrical Specifications – DC and AC

44. 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).

45. 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 42: of series resistance is used between the VTT supply and

the input pin.

46. The current Micron part operates below 83 MHz (slowest specified JEDEC operating

frequency). As such, future die may not reflect this option.

47. When an input signal is HIGH or LOW, it is defined as a steady state logic HIGH or

LOW.

48. Random address is changing; 50% of data is changing at every transfer.

49. Random address is changing; 100% of data is changing at every transfer.

50. 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.

51. 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.”

52. 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.

53. 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.

54. The -6/-6T speed grades will operate with tRAS (MIN) = 40ns and

tRAS (MAX) = 120,000ns at any slower frequency.

55. DRAM devices should be evenly addressed when being accessed. Disproportionate

accesses to a particular row address may result in reduction of the product lifetime.

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256Mb: x4, x8, x16 DDR SDRAM

Electrical Specifications – DC and AC

Table 18: Normal Output Drive Characteristics

Characteristics are specified under best, worst, and nominal process variation/conditions

Voltage

(V)

Pull-Down Current (mA) Pull-Up Current (mA)

Nominal

Low

Nominal

High Min Max

Nominal

Low

Nominal

High Min Max

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

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256Mb: x4, x8, x16 DDR SDRAM

Electrical Specifications – DC and AC

Table 19: Reduced Output Drive Characteristics

Characteristics are specified under best, worst, and nominal process variation/conditions

Voltage

(V)

Pull-Down Current (mA) Pull-Up Current (mA)

Nominal

Low

Nominal

High Min Max

Nominal

Low

Nominal

High Min Max

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

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256Mb: x4, x8, x16 DDR SDRAM

Commands

Tables 20 and 21 provide a quick reference of available commands. Two additional Truth

Tables—Table 22 on page 44 and Table 23 on page 45—provide current state/next state

information.

Notes: 1. DESELECT and NOP are functionally interchangeable.

2. BA[1:0] provide bank address and A[n:0] (128Mb: n = 11; 256Mb and 512Mb: n = 12; 1Gb: n

= 13) provide row address.

3. BA[1:0] provide bank address; A[i:0] provide column address, (where Aiis the most signifi-

cant column address bit for a given density and configuration, see Table 2 on page 2) A10

HIGH enables the auto precharge feature (non persistent), and A10 LOW disables the auto

precharge feature.

4. 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.

5. A10 LOW: BA[1:0] determine which bank is precharged. A10 HIGH: all banks are precharged

and BA[1:0] 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 while in self refresh mode, all inputs and

I/Os are “Don’t Care” except for CKE.

8. BA[1:0] 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 combina-

tions of BA[1:0] are reserved). A[n:0] provide the op-code to be written to the selected

mode register.

Table 20: Truth Table 1 – Commands

CKE is HIGH for all commands shown except SELF REFRESH; All states and sequences not shown are illegal or

reserved

Function CS# RAS# CAS# WE# Address Notes

DESELECT HXXX X 1

NO OPERATION (NOP) LHHH X 1

ACTIVE (select bank and activate row) L L H H Bank/row 2

READ (select bank and column and start READ burst) L H L H Bank/col 3

WRITE (select bank and column and start WRITE burst) L H L L Bank/col 3

BURST TERMINATE LHHL X 4

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-code8

Table 21: Truth Table 2 – DM Operation

Used to mask write data, provided coincident with the corresponding data

Name (Function) DM DQ

Write enable L Valid

Write inhibit H X

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256Mb: x4, x8, x16 DDR SDRAM

Commands

Notes: 1. This table applies when CKEn-1 was HIGH and CKEn is HIGH (see Table 25 on page 47) and

after tXSNR has been met (if the previous state was self refresh).

2. This table is bank-specific, except where noted (that is, 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. COM-

MAND 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 22 and according to Table 23 on

page 45.

• 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 with auto precharge enabled: Starts with registration of a READ command with

auto precharge enabled and ends when tRP has been met. Once tRP is met, the bank

will be in the idle state.

• Write with 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 22: Truth Table 3 – Current State Bank n – Command to Bank n

Notes: 1–6 apply to the entire table; Notes appear below

Current State CS# RAS# CAS# WE# Command/Action Notes

Any HXXX

DESELECT (NOP/continue previous operation)

LHHH

NO OPERATION (NOP/continue previous operation)

Idle LLHH

ACTIVE (select and activate row)

LLLH

AUTO REFRESH 7

LLLL

LOAD MODE REGISTER 7

Row active LHLH

READ (select column and start READ burst) 10

LHLL

WRITE (select column and start WRITE burst) 10

LLHL

PRECHARGE (deactivate row in bank or banks) 8

Read

(auto precharge

disabled)

LHLH

READ (select column and start new READ burst) 10

LHLL

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

LLHL

PRECHARGE (truncate READ burst, start PRECHARGE) 8

LHHL

BURST TERMINATE 9

Write

(auto precharge

disabled)

LHLH

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

LHLL

WRITE (select column and start new WRITE burst) 10

LLHL

PRECHARGE (truncate WRITE burst, start

PRECHARGE)

8, 11

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256Mb: x4, x8, x16 DDR SDRAM

Commands

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

is met. After tRFC is met, the DDR SDRAM will be in the all banks idle state.

• Accessing mode register: Starts with registration of an LMR command and ends when

tMRD has been met. After 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. After 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.

Notes: 1. This table applies when CKEn-1 was HIGH and CKEnis HIGH (see Table 25 on page 47) and

after tXSNR has been met (if the previous state was self refresh).

Table 23: Truth Table 4 – Current State Bank n – Command to Bank m

Notes: 1–6 apply to the entire table; Notes appear on page 45

Current State CS# RAS# CAS# WE# Command/Action Notes

Any HXXX

DESELECT (NOP/continue previous operation)

LHHH

NO OPERATION (NOP/continue previous operation)

Idle XXXX

Any command otherwise allowed to bank m

Row activating, active,

or precharging

LLHH

ACTIVE (select and activate row)

LHLH

READ (select column and start READ burst) 7

LHLL

WRITE (select column and start WRITE burst) 7

LLHL

PRECHARGE

Read (auto precharge

disabled)

LLHH

ACTIVE (select and activate row)

LHLH

READ (select column and start new READ burst) 7

LHLL

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

LLHL

PRECHARGE

Write (auto precharge

disabled)

LLHH

ACTIVE (select and activate row)

LHLH

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

LHLL

WRITE (select column and start new WRITE burst) 7

LLHL

PRECHARGE

Read (with auto-

precharge)

LLHH

ACTIVE (select and activate row)

LHLH

READ (select column and start new READ burst) 7

LHLL

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

LLHL

PRECHARGE

Write (with auto-

precharge)

LLHH

ACTIVE (select and activate row)

LHLH

READ (select column and start READ burst) 7

LHLL

WRITE (select column and start new WRITE burst) 7

LLHL

PRECHARGE

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256Mb: x4, x8, x16 DDR SDRAM

Commands

2. This table describes alternate bank operation, except where noted (that is, the current state

is for bank n, and the commands shown are those allowed to be issued to bank m, assuming

that bank m is in such a state that the given command is allowable). Exceptions are covered

in the notes below.

3. Current state definitions:

• Idle: The bank has been precharged, and 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 note 3a below.

• Write with auto precharge enabled: See note 3a below.

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. 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 interrupt the read or write data transfer already in

process. In either case, all other related limitations apply (for example, 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 in Table 24.

4. AUTO REFRESH and LMR 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 24: Command Delays

CLRU = CL rounded up to the next integer

From

Command To Co mma nd

Minimum Delay

with Concurrent Auto Precharge

WRITE with auto

precharge

READ or READ with auto precharge [1 + (BL/2)] × tCK + tWTR

WRITE or WRITE with auto precharge (BL/2) × tCK

PRECHARGE 1 tCK

ACTIVE 1 tCK

READ with auto

precharge

READ or READ with auto precharge (BL/2) × tCK

WRITE or WRITE with auto precharge [CLRU + (BL/2)] × tCK

PRECHARGE 1 tCK

ACTIVE 1 tCK

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256Mb: x4, x8, x16 DDR SDRAM

Commands

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 (tRPST); 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 spec-

ified range.

7. Upon exit of the self refresh mode, the DLL is automatically enabled. 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 occurring during the tXSNR period.

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 prog-

ress 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 (LMR)

The mode registers are loaded via inputs A0–An(see "REGISTER DEFINITION" on page

55). The LMR command can only be issued when all banks are idle, and a subsequent

executable command cannot be issued until tMRD is met.

Table 25: Truth Table 5 – CKE

Notes 1–6 apply to the entire table; Notes appear below

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 20 on page 43

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256Mb: x4, x8, x16 DDR SDRAM

Commands

ACTIVE (ACT)

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

subsequent access, like a read or a write, as shown in Figure 8. The value on the BA0, BA1

inputs selects the bank, and the address provided on inputs A[n:0] selects the row.

Figure 8: Activating a Specific Row in a Specific Bank

CS#

WE#

CAS#

RAS#

CKE

Address Row

HIGH

BA0, BA1 Bank

CK#

Don’tCare

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256Mb: x4, x8, x16 DDR SDRAM

Commands

READ

The READ command is used to initiate a burst read access to an active row, as shown in

Figure 9 on page 49. The value on the BA0, BA1 inputs selects the bank, and the address

provided on inputs A[i:0] (where Ai is the most significant column address bit for a given

density and configuration, see Table 2 on page 2) selects the starting column location.

Figure 9: READ Command

Note: EN AP = enable auto precharge; DIS AP = disable auto precharge.

CS#

WE#

CAS#

RAS#

CKE

Address

A10

BA0, BA1

HIGH

CK#

Don’tCare

Col

DIS AP

EN AP

Bank

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256Mb: x4, x8, x16 DDR SDRAM

Commands

WRITE

The WRITE command is used to initiate a burst write access to an active row as shown in

Figure 10. The value on the BA0, BA1 inputs selects the bank, and the address provided

on inputs A[i:0] (where Ai is the most significant column address bit for a given density

and configuration, see Table 2 on page 2) selects the starting column location.

Figure 10: WRITE Command

Note: EN AP = enable auto precharge; and DIS AP = disable auto precharge.

CS#

WE#

CAS#

RAS#

CKE

A10

BA0, BA1

HIGH

CK#

Don’tCare

Address Col

EN AP

DIS AP

Bank

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256Mb: x4, x8, x16 DDR SDRAM

Commands

PRECHARGE (PRE)

The PRECHARGE command is used to deactivate the open row in a particular bank or

the open row in all banks as shown in Figure 11. The value on the BA0, BA1 inputs selects

the bank, and the A10 input selects whether a single bank is precharged or whether all

banks are precharged.

Figure 11: PRECHARGE Command

Notes: 1. If A10 is HIGH, bank address becomes “Don’t Care.”

BURST TERMINATE (BST)

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

precharge disabled). The most recently registered READ command prior to the BURST

TERMINATE command will be truncated, as shown in “Operations” on page 52. The

open page from which the READ burst was terminated remains open.

AUTO REFRESH (AR)

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 nonpersis-

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

AUTO REFRESH command is issued.

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. The SELF REFRESH command is initiated like an

AUTO REFRESH command except CKE is disabled (LOW).

CS#

WE#

CAS#

RAS#

CKE

A10

BA0, BA1

HIGH

Address

CK#

Don’tCare

Bank1

All banks

One bank

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256Mb: x4, x8, x16 DDR SDRAM

Operations

INITIALIZATION

Prior to normal operation, DDR SDRAMs must be powered up and initialized in a

predefined manner. Operational procedures, other than those specified, may result in

undefined operation.

To ensure device operation, the DRAM must be initialized as described in the following

steps:

1. Simultaneously apply power to VDD and VDDQ.

2. Apply VREF and then VTT power. VTT must be applied after VDDQ to avoid device latch-

up, which may cause permanent damage to the device. Except for CKE, inputs are not

recognized as valid until after VREF is applied.

3. Assert and hold CKE at a LVCMOS logic LOW. 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).

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 SSTL_2 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 and E2–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. 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. 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. 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 an LMR command to

clear the DLL bit (set M8 = 0). If an 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 supported.

21. At this point the DRAM is ready for any valid command. At least 200 clock cycles with

CKE HIGH are required between step 11 (DLL RESET) and any READ command.

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256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 12: INITIALIZATION Flow Diagram

and V

DDQ

ramp

Apply V

REF

and V

CKE must be LVCMOS LOW

Apply stable clocks

BringCKE HIGH with a NOP command

Wait at least 200µs

PRECHARGE ALL

Assert NOP or DESELECT for

RP time

Configure extended mode register

Configure load mode register and reset DLL

Assert NOP or DESELECT for

MRD time

Assert NOP or DESELECT for

MRD time

PRECHARGE ALL

Issue AUTO REFRESHcommand

Assert NOP or DESELECT for

RFC time

Optional LMR command to clear DLL bit

Assert NOP or DESELECT for

MRD time

DRAM is ready for any validcommand

Step

Assert NOP or DESELECTcommands for

RFC

Issue AUTO REFRESHcommand

Assert NOP or DESELECT for

RP time

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256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 13: INITIALIZATION Timing Diagram

Notes: 1. VTT is not applied directly to the device; however, tVTD t 0 to avoid device latch-up. VDDQ,

VTT, and VREF d VDD + 0.3V. Alternatively, VTT may be 1.35V maximum during power-up,

even if VDD/VDDQ are 0V, provided a minimum of 42:of series resistance is used between

the VTT supply and the input pin. Once initialized, VREF must always be powered within the

specified range.

2. Although not required by the Micron device, JEDEC specifies issuing another LMR command

(A8 = 0) prior to activating any bank. If another LMR command is issued, the same, previ-

ously issued operating parameters must be used.

3. The two AUTO REFRESH commands at Td0 and Te0 may be applied following the LMR com-

mand at Ta0.

4. tMRD is required before any command can be applied (during MRD time only NOPs or

DESELECTs are allowed), and 200 cycles of CK are required before a READ command can be

issued.

5. While programming the operating parameters, reset the DLL with A8 = 1.

tVTD1

CKE LVCMOS

LOW level

BA0, BA1

200 cycles of CK4

Load extended

mode register Load mode

register5

tMRD tMRD tRP tRFC tRFC

tIS

Power-up: V

and CK stable

T = 200µs

High-Z

tIH

DQS High-Z

Address RA

A10

All banks

CK#

tCH tCL

tCK

REF

Command LMRNOP PRELMR AR AR ACT2

tIS tIH

BA0 = 1

BA1 = 0

tIS tIH tIS tIH

BA0 = 0

BA1 = 0

tIS tIH

(

)(

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(

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(

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(

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Code Code

tIS tIH

Code Code3

PRE

All banks

tIS tIH

T0 T1 Ta0 Tb0 Tc0 Td0 Te0 Tf0

(

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Don’t Care

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Indicates A Break in

Time Scale

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256Mb: x4, x8, x16 DDR SDRAM

Operations

Mode Register

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

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

operating mode, as shown in Figure 14. The mode register is programmed via the LMR

command (with BA0 = 0 and BA1 = 0) and will retain the stored information until it is

programmed again or until 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 A[2:0] specify the burst length, A3 specifies the type of burst (sequen-

tial or interleaved), A[6:4] specify the CAS latency, and A[n:7] specify the operating

mode.

Figure 14: Mode Register Definition

Notes: 1. n is the most significant row address bit from Table 2 on page 2.

Burst Type

Sequential

Interleaved

CAS Latency

Reserved

3 (-5B only)

Reserved

2.5

Reserved

Burst lengthCAS Latency BT0

A9 A7 A6 A5 A4 A3A8 A2 A1 A0

Mode register

(Mx)

Address bus

9765438210

Operating mode

. . .AnBA0BA1

. . .

n+ 1

n+ 2

Operating Mode

Normal operation

Normal operation/reset DLL

All other states reserved

–

. . .

–

M6–M0

Valid

–

Burst Length

Reserved

Mn+ 1

Mode Register Definition

Base mode register

Extended mode register

Reserved

Mn+ 2

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256Mb: x4, x8, x16 DDR SDRAM

Operations

Burst Length (BL)

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

being programmable for both READ and WRITE bursts, as shown in Figure 14 on

page 55. The burst length determines the maximum number of column locations that

can be accessed for a given READ or WRITE command. BL = 2, BL = 4, or BL = 8 locations

are available for both the sequential and the interleaved 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 A[i:1] when BL = 2, by A[i:2] when BL = 4, and by A[i:3] when BL = 8

(where Ai is the most significant column address bit for a given configuration). The

remaining (least significant) address bit(s) is (are) used to select the starting location

within the block. For example: for BL = 8, A[i:3]select the eight-data-element block;

A[2:0] select the first access within the block.

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 26.

Table 26: Burst Definition

Burst Length Starting Column Address

Order of Accesses Within a Burst

Type = Sequential Type = Interleaved

2––A0 ––

––0 0-1 0-1

––1 1-0 1-0

4–A1 A0 ––

– 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

8A2 A1 A0 ––

0 0 0 0-1-2-3-4-5-6-7 0-1-2-3-4-5-6-7

0 0 1 1-2-3-4-5-6-7-0 1-0-3-2-5-4-7-6

0 1 0 2-3-4-5-6-7-0-1 2-3-0-1-6-7-4-5

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

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256Mb: x4, x8, x16 DDR SDRAM

Operations

CAS Latency (CL)

The CL is the delay, in clock cycles, between the registration of a READ command and

the availability of the first bit of output data. The latency can be set to 2, 2.5, or 3 (-5B

only) clocks, as shown in Figure 15. Reserved states should not be used, as unknown

operation or incompatibility with future versions may result.

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 27 on page 58 indi-

cates the operating frequencies at which each CL setting can be used.

Figure 15: CAS Latency

Note: BL = 4 in the cases shown; shown with nominal tAC, tDQSCK, and tDQSQ.

CK#

Command

DQS

CL = 2

READ NOP NOP NOP

CK#

Command

DQS

CL = 2.5

T0 T1 T2 T2n T3 T3n

Don’tCareTransitioning Data

READ NOP NOP NOP

CK#

Command

DQS

CL = 3

T0 T1 T2 T3 T3n

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256Mb: x4, x8, x16 DDR SDRAM

Operations

Operating Mode

The normal operating mode is selected by issuing an LMR command with bits A7–An

each set to zero and bits A[6:0] set to the desired values. A DLL reset is initiated by

issuing an LMR command with bits A7 and A[n:9] each set to zero, bit A8 set to one, and

bits A[6:0] set to the desired values. Although not required by the Micron device, JEDEC

specifications recommend that an LMR command resetting the DLL should always be

followed by an LMR command selecting normal operating mode.

All other combinations of values for A[n:7] are reserved for future use and/or test modes.

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

ibility 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 16 on page 59. The extended

mode register is programmed via the LMR command to the mode register (with BA0 = 1

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

the device loses power. The enabling of the DLL should always be followed by an LMR

command to the mode register (BA0/BA1 = 0) to reset the DLL. The extended mode

controller must wait the specified time before initiating any subsequent operation.

Violating either requirement could result in an unspecified operation.

Output Drive Strength

The normal drive strength for all outputs is specified to be SSTL_2, Class II. The Design

Revision F and K devices support a programmable option for reduced drive. This option

is intended for the support of the lighter load and/or point-to-point environments. The

selection of the reduced drive strength will alter the DQ and DQS pins from SSTL_2,

Class II drive strength to a reduced drive strength, which is approximately 54% 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). Anytime the DLL is enabled, 200 clock cycles with CKE HIGH

must occur before a READ command can be issued.

Table 27: CAS Latency

Speed

Allowable Operating Clock Frequency (MHz)

CL = 2 CL = 2.5 CL = 3

-5B 75 dfd 133 75 dfd 167 133 dfd 200

-6/-6T 75 dfd 133 75 dfd 167 –

-75E 75 dfd 133 75 dfd 133 –

-75Z 75 dfd 133 75 dfd 133 –

-75 75 dfd 100 75 dfd 133 –

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256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 16: Extended Mode Register Definition

Notes: 1. n is the most significant row address bit from Table 2 on page 2.

2. The QFC# option is not supported.

ACTIVE

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 17 on page 60, which covers

any case where 2 < tRCD (MIN)/tCK d 3 (Figure 17 also shows the same case for tRRD; the

same procedure is used to convert other specification limits from time units to clock

cycles).

A 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.

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

interval 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.

Operating Mode

Reserved

–

E1, E0

Valid

–

DLL

Enable

Disable

A9 A7 A6 A5 A4 A3A8 A2 A1 A0

Extended mode

Address bus

976543821

Drive Strength

Normal

Reduced

Operating Mode

. . .AnBA1 BA0

. . .n1

n+ 1n+ 2

–

. . .

–

E22

–

Mn+ 1

Mode Register Definition

Base mode register

Extended mode register

Reserved

Mn+ 2

DLL

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256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 17: Example: Meeting tRCD (tRRD) MIN When 2 < tRCD (tRRD) MIN/tCK d3

READ

During the READ command, 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.

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 CL after the READ command. Each subsequent data-out

element will be valid nominally at the next positive or negative clock edge (that is, at the

next crossing of CK and CK#). Figure 18 on page 62 shows the general timing for each

possible CL 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 DQ

will go High-Z. Detailed explanations of tDQSQ (valid data-out skew), tQH (data-out

window hold), and the valid data window are depicted in Figure 26 on page 70 and

Figure 27 on page 71. Detailed explanations of tDQSCK (DQS transition skew to CK) and

tAC (data-out transition skew to CK) are depicted in Figure 28 on page 72.

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

quent 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 19 on page 63. A READ command can be initiated

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

illustrated in Figure 20 on page 64. Full-speed random read accesses within a page (or

pages) can be performed, as shown in Figure 21 on page 65.

Command

BA0, BA1

ACTACT

NOP

tRRD tRCD

CK#

Bank xBank y

Address Row Row

NOP

RD/WR

NOP

Bank y

Col

NOP

T0 T1 T2 T3 T4 T5 T6T7

Don’tCare

NOP

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256Mb: x4, x8, x16 DDR SDRAM

Operations

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

shown in Figure 22 on page 66. The BURST TERMINATE latency is equal to the CL, that

is, 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 23 on page 67. 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 acti-

vated.

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 24 on page 68. Following the PRECHARGE

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

and tRP have been met. Part of the row precharge time is hidden during the access of the

last data elements.

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256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 18: READ Burst

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

2. BL = 4.

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

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

READ NOP NOP NOP NOP NOP

CL = 2

CL = 2.5

T0 T1 T2 T3T2n T3n T4 T5

READ NOP NOP NOP NOP NOP

CL = 3

T0 T1 T2 T3 T4nT3n T4 T5

Bank a,

Col n

Bank a,

Col n

Bank a,

Col n

Command

Address

DQS

CK#

Command

Address

DQS

CK#

Command

Address

DQS

CK#

Transitioning Data Don’t Care

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256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 19: Consecutive READ Bursts

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

2. BL = 4 or BL = 8 (if BL = 4, the bursts are concatenated; if BL = 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 follow-

ing DO b.

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

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

READ NOP READ NOP NOP NOP

CL = 2

CL = 2.5

T0 T1 T2 T3T2n T3n T4 T5T4n T5n

READ NOP READ NOP NOP NOP

CL = 3

T0 T1 T2 T3 T3n T4 T5T4n T5n

Bank,

Col n

Bank,

Col b

Bank,

Col n

Bank,

Col b

Bank,

Col n

Bank,

Col b

Command

Address

DQS

CK#

Command

Address

DQS

CK#

Command

Address

DQS

CK#

Transitioning Data Don’t Care

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256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 20: Nonconsecutive READ Bursts

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

2. BL = 4 or BL = 8 (if BL = 4, the bursts are concatenated; if BL = 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 follow-

ing DO b.

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

READ NOP NOP NOP NOP NOPREAD

CL = 2

CL = 2.5

T0 T1 T2 T3T2n T3n T4 T5 T5n T6

READ NOP NOP NOP NOP NOPREAD

T0 T1 T2 T3T2n T3n T4 T5 T5n T6

CL = 3

READ NOP NOP NOP NOP NOPREAD

T0 T1 T2 T3 T3n T4 T5 T6

T4n

Bank,

Col n

Bank,

Col b

Bank,

Col n

Bank,

Col b

Bank,

Col n

Bank,

Col b

Command

Address

DQS

CK#

Command

Address

DQS

CK#

Command

Address

DQS

CK#

Transitioning Data Don’tCare

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Operations

Figure 21: Random READ Accesses

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

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

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

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

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

READ READ READ NOP NOPREAD

CL = 2

CL = 2.5

T0 T1 T2 T3T2n T3n T4 T5T4n T5n

READ READ READ NOP NOPREAD

T0 T1 T2 T3T2n T3n T4 T5T4n T5n

CL = 3

READ READ READ NOP NOPREAD

T0 T1 T2 T3 T3n T4 T5T4n T5n

Bank,

Col n

Bank,

Col b

Bank,

Col x

Bank,

Col g

Bank,

Col n

Bank,

Col b

Bank,

Col x

Bank,

Col g

Bank,

Col n

Bank,

Col b

Bank,

Col x

Bank,

Col g

Command

Address

DQS

CK#

Command

Address

DQS

CK#

Command

Address

DQS

CK#

Transitioning Data Don’tCare

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Operations

Figure 22: Terminating a READ Burst

Notes: 1. Page remains open.

2. DO n = data-out from column n.

3. BL = 4.

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

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

READ NOP NOP NOP NOP

Bank a,

Col n

READ NOP NOP NOP NOP

Bank a,

Col n

CL = 2

CL = 2.5

T0 T1 T2 T3T2n T4 T5

READ NOP NOP NOP NOP

Bank a,

Col n

CL = 3

T0 T1 T2 T3 T3n T4 T5

BST1

Command

Address

DQS

CK#

Command

Address

DQS

CK#

Command

Address

DQS

CK#

Transitioning Data Don’t Care

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Operations

Figure 23: READ-to-WRITE

Notes: 1. Page remains open.

2. DO n = data-out from column n; DI b = data-in from column b.

3. BL = 4 (applies for bursts of 8 as well; if BL = 2, the BURST 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.

READ BST1NOP NOP NOP

Bank,

Col n

WRITE

Bank,

Col b

T0 T1 T2 T3T2n T4 T5T4n T5n

(NOM)

DQSS

READ BST1NOP WRITE NOP

Bank a,

Col n

NOP

T0 T1 T2 T3 T3n T4 T5 T5n

(NOM)

DQSS

READ NOP NOP

Bank,

Col n

WRITE

Bank,

Col b

T0 T1 T2 T3T2n T4 T5 T5n

(NOM)

DQSS

NOP

CL = 2.5

CL = 2

T3n

CL = 3

BST1

Command

Address

DQS

CK#

Command

Address

DQS

CK#

Command

Address

DQS

CK#

Transitioning Data Don’tCare

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Operations

Figure 24: READ-to-PRECHARGE

Notes: 1. Provided tRAS (MIN) is met, a READ command with auto precharge enabled would cause a

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

x=BL/2.

2. DO n = data-out from column n.

3. BL = 4 or an interrupted burst of 8.

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

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

6. READ-to-PRECHARGE equals two clocks, which allows two data pairs of data-out; it is also

assumed that tRAS (MIN) is met.

7. An ACTIVE command to the same bank is only allowed if tRC (MIN) is met.

READ NOP PRE NOP NOP ACT

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

CL = 2.5

T0 T1 T2 T3T2n T3n T4 T5

Bank a,

(a or all)

Bank a,

Row

READ NOP PRE NOP NOP ACT

Bank a,

Col n

tRP

CL = 3

T0 T1 T2 T3 T4nT3n T4 T5

Bank a,

(a or all)

Bank a,

Row

Command

Address

DQS

CK#

Command

Address

DQS

CK#

Command

Address

DQS

CK#

Transitioning Data Don’tCare

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Operations

Figure 25: Bank READ – Without Auto Precharge

Notes: 1. NOP commands are shown for ease of illustration; other commands may be valid at these

times.

2. BL = 4.

3. The PRECHARGE command can only be applied at T5 if tRAS (MIN) is met.

4. Disable auto precharge.

5. “Don’t Care” if A10 is HIGH at T5.

6. DO n (or b) = data-out from column n (or column b); subsequent elements are provided in

the programmed order.

7. Refer to Figure 26 on page 70, Figure 27 on page 71, and Figure 28 on page 72 for detailed

DQS and DQ timing.

CK#

CKE

A10

BA0, BA1

tCK tCH tCL

tIS

tIH

tIS

tIH

tIS tIH

tRCD

tRC

tRP

CL = 2

T0 T1 T2 T3 T4 T5 T5n T6nT6 T7 T8

DQS

Case 1: tAC

(

MIN)

and tDQSCK

(

MIN)

Case 2: tAC

(

MAX)

and tDQSCK

(

MAX)

DQS

RPRE

tRPRE

tRPST

DQSCK

(

MIN)

(

MIN)

(

MIN)

(

MIN)

(

MAX)

(

MAX)

ACT

Col n

Bank xBank x

ACT

Bank x

DQSCK (MAX)

NOP1NOP1NOP1NOP1NOP1

READ2PRE3

Bank x5

tRAS3

Row

Command

Address

Transitioning Data Don’t Care

All banks

One bank

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Operations

Figure 26: x4, x8 Data Output Timing – tDQSQ, tQH, and Data Valid Window

Notes: 1. tHP is the lesser of tCL or tCH clock transition collectively when a bank is active.

2. tDQSQ is derived at each DQS clock edge, is not cumulative over time, begins with DQS

transition, and ends with the last valid DQ transition.

3. DQ transitioning after DQS transition define the tDQSQ window. DQS transitions at T2 and

T2n are an “early DQS”; at T3, a “nominal DQS”; and at T3n, a “late DQS”.

4. For a x4, only two DQ apply.

5. tQH is derived from tHP: tQH = tHP - tQHS.

6. The data valid window is derived for each DQS transitions and is defined as tQH - tDQSQ.

DQ (last data valid)

DQ4

DQS3

DQ (last data valid)

DQ (first data no longer valid)

All DQ and DQScollectively6

Earliest signal transition

Latest signal transition

T2n

T3n

CK#

T1 T2 T3 T4T2n T3n

tQH5

tHP

tQH5tQH5

tHP

tQH5

tDQSQ

Data

valid

window

Data

valid

window

Data

valid

window

Data

valid

window

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Operations

Figure 27: x16 Data Output Timing – tDQSQ, tQH, and Data Valid Window

Notes: 1. tHP is the lesser of tCL or tCH clock transition collectively when a bank is active.

2. tDQSQ is derived at each DQS clock edge, is not cumulative over time, begins with DQS

transition, and ends with the last valid DQ transition.

3. DQ transitioning after DQS transition define the tDQSQ window. LDQS defines the lower

byte, and UDQS defines the upper byte.

4. DQ0, DQ1, DQ2, DQ3, DQ4, DQ5, DQ6, or DQ7.

5. tQH is derived from tHP: tQH = tHP - tQHS.

6. The data valid window is derived for each DQS transition and is tQH - tDQSQ.

7. DQ8, DQ9, DQ10, D11, DQ12, DQ13, DQ14, or DQ15.

DQ (last data valid)4

DQ4

LDQS3

DQ (last data valid)4

DQ (first data no longer valid)4

DQ0–DQ7 and LDQScollectively6

T2n

T3n

CK#

T1 T2 T3 T4T2n T3n

tQH5tQH5

tDQSQ

Data valid

window

Data valid

window

DQ (last data valid)7

DQ7

UDQS3

DQ (last data valid)7

DQ (first data no longer valid)7

DQ8–DQ15 and UDQScollectively6

T2n

T3n

tQH5tQH5tQH5tQH5

tDQSQ2tDQSQ2tDQSQ2

tDQSQ2

tHP

tQH5

Data valid

window

Data valid

window

Data valid

window

Data valid

window

Data valid

window

Upper byte

Lower byte

Data valid

window

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Operations

Figure 28: Data Output Timing – tAC and tDQSCK

Notes: 1. READ command with CL = 2 issued at T0.

2. tDQSCK is the DQS output window relative to CK and is the “long term” component of the

DQS skew.

3. DQ transitioning after DQS transition define the tDQSQ window.

4. All DQ must transition by tDQSQ after DQS transitions, regardless of tAC.

5. tAC is the DQ output window relative to CK and is the “long term” component of DQ skew.

6. tLZ (MIN) and tAC (MIN) are the first valid signal transitions.

7. tHZ (MAX) and tAC (MAX) are the latest valid signal transitions.

WRITE

During a WRITE command, 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 (after tWR time); 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

corresponding data will be written to memory. If the DM signal is registered HIGH, the

corresponding data inputs will be ignored, and a WRITE will not be executed to that

byte/column location.

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

registered on successive edges of DQS. The LOW state on DQS between the WRITE

command 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% to 125% of one clock cycle).

All of the WRITE diagrams show the nominal case, and where the two extreme cases

(that is, tDQSS [MIN] and tDQSS [MAX]) might not be intuitive; they have also been

included. Figure 29 on page 74 shows the nominal case and the extremes of tDQSS for

BL = 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.

CK#

DQS or LDQS/UDQS3

T1 T2 T3 T4 T5

T2n T3n T4n T5n T6

tRPST

tLZ (MIN)

tDQSCK2(MAX)

tDQSCK2(MIN)

tDQSCK2(MAX)

tDQSCK2(MIN)

tHZ (MAX)

All DQ values collectively4

tAC5(MIN) tAC5(MAX)

tLZ (MIN) tHZ (MAX)

T2n T3n T4n T5n

T2n

T3n

T4n

T5n

T2 T3 T4 T5

DQ (last data valid)

DQ (first data valid)

T01

tRPRE

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Operations

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

previous 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 30 on page 75 shows concatenated bursts of 4. An example of nonconsecutive

WRITEs is shown in Figure 31 on page 76. Full-speed random write accesses within a

page or pages can be performed as shown in Figure 32 on page 76.

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 33

on page 77.

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

in Figure 34 on page 78.

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 35 on page 79.

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 36 on page 80.

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

shown in Figure 37 on page 81 and Figure 38 on page 82. Only the data-in pairs regis-

tered prior to the tWR period are written to the internal array; any subsequent data-in

should be masked with DM, as shown in Figures 37 and 38. After the PRECHARGE

command, a subsequent command to the same bank cannot be issued until tRP is met.

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Operations

Figure 29: 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 b.

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

DQ DI

Don’t CareTransitioning Data

tDQSS

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Operations

Figure 30: Consecutive WRITE-to-WRITE

Notes: 1. DI b (or n) = data-in from column b (or column n).

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.

Address

tDQSS (NOM)

CK#

Command WRITE NOP WRITE NOP NOP

Bank,

Col b

NOP

Bank,

Col n

T0 T1 T2 T3T2n T4 T5T4nT3nT1n

DQS

Don’t CareTransitioning Data

tDQSS

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Operations

Figure 31: Nonconsecutive WRITE-to-WRITE

Notes: 1. DI b (or n) = data-in from column b (or column n).

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 32: Random WRITE Cycles

Notes: 1. DI b (or x or nor a or g) = data-in from column b (or column x, or column n, or column a,or

column g).

2. b', x', n', a'or g'indicate the next data-in following DO b, DO x, DO n,DOa, or DO g,

respectively.

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

4. Each WRITE command may be to any bank.

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 CareTransitioning Data

CK#

tDQSS (NOM)

CK#

Command WRITE WRITE WRITE WRITE NOP

Address Bank,

Col bBank,

Col xBank,

Col nBank,

Col g

WRITE

Bank,

Col a

T0 T1 T2 T3T2n T4 T5T4nT1n T3n T5n

DQS

bDI

b'DI

xDI

x'DI

nDI

n'DI

aDI

a'DI

gDI

Don’t CareTransitioning Data

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Operations

Figure 33: 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 b.

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 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 CareTransitioning Data

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Operations

Figure 34: WRITE-to-READ – 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; 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 is used, DM and DQS are required at T3 and T3n because the READ com-

mand will 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 CareTransitioning Data

tDQSS

T3n

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Operations

Figure 35: 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 is used, DM and DQS are required at T3–T3n because the READ command

will 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 CareTransitioning Data

tDQSS

T3n

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Operations

Figure 36: 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 b.

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).

tDQSS (NOM)

CK#

Command WRITE NOP NOP NOP NOP

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 CareTransitioning Data

tDQSS

PRE

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Operations

Figure 37: 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 is used, DQS and DM are not required at T3, T3n, T4, and T4n.

tDQSS

tDQSS (NOM)

CK#

Command WRITE NOP NOP NOP 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 CareTransitioning Data

T3n T4n

PRE

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256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 38: 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 is used, DQS and DM are not required at T3, T3n, T4, and T4n.

tDQSS

tDQSS (NOM)

CK#

Command WRITE NOP NOP NOP 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 CareTransitioning Data

T3n T4n

PRE

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256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 39: Bank WRITE – Without Auto Precharge

Notes: 1. NOP commands are shown for ease of illustration; other commands may be valid at these

times.

2. BL = 4.

3. Disable auto precharge.

4. “Don’t Care” if A10 is HIGH at T8.

5. DI b = data-in from column b; subsequent elements are provided in the programmed order.

6. See Figure 41 on page 85 for detailed DQ timing.

Command NOP1NOP1NOP1NOP1NOP1NOP1

WRITE2

Bank x4

DQ5

Address

Row

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

ACT

Col n

One bank

All banks

Bank x

PRE

Bank x

tDQSL tDQSH tWPST

DQS

tDS tDH

tDQSS (NOM)

tWPRE

tWPRES

Don’t CareTransitioning Data

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256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 40: WRITE – DM Operation

Notes: 1. NOP commands are shown for ease of illustration; other commands may be valid at these

times.

2. BL = 4.

3. Disable auto precharge.

4. “Don’t Care” if A10 is HIGH at T8.

5. DI b = data-in from column b; subsequent elements are provided in the programmed order.

6. See Figure 41 on page 85 for detailed DQ timing.

Command NOP1NOP1NOP1NOP1NOP1NOP1

Bank x4

DQ5

WRITE2

Address Row

Row

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

ACT

Col n

One bank

All banks

Bank x

PRE

Bank x

tDQSL tDQSH tWPST

DQS

tDS tDH

Don’t CareTransitioning Data

tDQSS (NOM)

tWPRES tWPRE

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256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 41: Data Input Timing

Notes: 1. WRITE command issued at T0.

2. tDSH (MIN) generally occurs during tDQSS (MIN).

3. tDSS (MIN) generally occurs during tDQSS (MAX).

4. For x16, LDQS controls the lower byte and UDQS controls the upper byte.

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

PRECHARGE

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 concurrent auto precharge. With

concurrent auto precharge, 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

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. When all banks are to be precharged, 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 which performs the same individual-bank precharge func-

tion 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

command. A precharge of the bank/row that is addressed with the READ or WRITE

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

Auto precharge is either enabled or disabled for each individual READ or WRITE

command. This device supports concurrent auto precharge if the command 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 “Operations” on page 52. The user must not issue another command

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

T01

tDSH2tDSH2

tDSS3tDSS3

DQS

tDQSS

tDQSH tWPST

tDH

tDS

tDQSL

CK#

T1 T1n T2 T2n T3

Don’t CareTransitioning Data

tWPRE

tWPRES

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256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 42: Bank READ – with Auto Precharge

Notes: 1. NOP commands are shown for ease of illustration; other commands may be valid at these

times.

2. BL = 4.

3. The READ command can only be applied at T3 if tRAP is satisfied at T3.

4. Enable auto precharge.

5. tRP starts only after tRAS has been satisfied.

6. DO n = data-out from column n; subsequent elements are provided in the programmed

order.

7. Refer to Figure 26 on page 70, Figure 27 on page 71, and Figure 28 on page 72 for detailed

DQS and DQ timing.

NOP1NOP1NOP1NOP1NOP1NOP1

tRCD, tRAP3

DQ6

Command

tRP5

Address

tLZ (MIN)

Row

CK#

CKE

A10

BA0, BA1

tCKtCHtCL

tIS

tIH

tIS

tIH

ISIH

tRC

CL = 2

T0 T1 T2 T3 T4 T5 T5n T6nT6T7 T8

DQS

Case 1: tAC (MIN) andtDQSCK (MIN)

Case 2: tAC(MAX) andtDQSCK(MAX)

DQS

tRPRE

tRPRE tRPST

tDQSCK(MIN)

tDQSCK(MAX)

tAC(MIN)

tLZ (MIN)

tHZ (MAX)

tAC(MAX)

ACT

Col n

Bank xBank x

ACT

Bank x

tRAS

Don’tCareTransitioning Data

tRPST

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256Mb: x4, x8, x16 DDR SDRAM

Operations

Figure 43: Bank WRITE – with Auto Precharge

Notes: 1. NOP commands are shown for ease of illustration; other commands may be valid at these

times.

2. BL = 4.

3. Enable auto precharge.

4. DI n = data-out from column n; subsequent elements are provided in the programmed

order.

5. See Figure 41 on page 85 for detailed DQ timing.

AUTO REFRESH

During auto refresh, the addressing is generated by the internal refresh controller. This

makes the address bits a “Don’t Care” during an AUTO REFRESH command. The DDR

SDRAM requires AUTO REFRESH cycles at an average interval of tREFI (MAX).

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 × tREFI(= tREFC). JEDEC specifications only support 8 × tREFI; Micron

specifications exceed 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.

Command NOP1NOP1NOP1NOP1NOP1NOP1NOP1

WRITE2

DQ4

Address Row

Row

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

ACT

Col n

Bank xBank x

tDQSL tDQSH tWPST

DQS

tDS tDH

tDQSS (NOM)

Don’t CareTransitioning Data

tWPRES tWPRE

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256Mb: x4, x8, x16 DDR SDRAM

Operations

Although not a JEDEC requirement, to provide for future functionality features, 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.

Figure 44: Auto Refresh Mode

Notes: 1. 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.

2. NOP or COMMAND INHIBIT are the only commands allowed until after tRFC time; CKE must

be active during clock-positive transitions.

3. The second AUTO REFRESH is not required and is only shown as an example of two back-to-

back AUTO REFRESH commands.

4. “Don’t Care” if A10 is HIGH at this point; A10 must be HIGH if more than one bank is active

(that is, must precharge all active banks).

5. DM, DQ, and DQS signals are all “Don’t Care”/High-Z for the operations shown.

SELF REFRESH

When in the self refresh mode, the DDR SDRAM retains data without external clocking.

The DLL is automatically disabled 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 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

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

refresh and DLL requirements is to apply NOPs for tXSRD time, then a DLL RESET (via

CK#

CommandNOP1

ValidValid

NOP1NOP1

PRE

CKE

Address

A10

BA0, BA1

Bank(s)4

AR NOP1,2 AR3NOP1,2 ACTNOP1

One bank

All banks

tIH

DQ5

DM5

DQS5

tRFC

tRP tRFC

T0 T1 T2 T3 T4 Ta0 Tb0

Ta1 Tb1Tb2

Don’tCare

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256Mb: x4, x8, x16 DDR SDRAM

Operations

the extended mode register) and NOPs for 200 additional clock cycles before applying a

READ. Any command other than a READ can be performed tXSNR (MIN) after the DLL

reset. NOP or DESELECT commands must be issued during the tXSNR (MIN) time.

Figure 45: 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.

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; that is only NOP or DESE-

LECT commands are allowed until Tb1.

6. tXSRD (200 cycles of a valid clock with 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, the self refresh mode may be re-entered

anytime after exiting if each of the following conditions is met:

7a. The DRAM had been in the self refresh mode for a minimum of 200ms prior to exiting.

7b. tXSNR and tXSRD are not violated.

7c. 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 the device is initialized, VREF must always be powered within specified range.

CK1

CK#

Command2NOP AR

Address

CKE

DQS

NOP

tRP4

tCHtCLtCK

tIS

tIH

tIStIH tIS

Enter self refresh mode7Exit self refresh mode7

T0 T11Ta1

Don’tCare

Ta01

tXSRD6

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256Mb: x4, x8, x16 DDR SDRAM

Operations

Power-down (CKE Not Active)

Unlike SDR SDRAMs, DDR SDRAMs require CKE to be active at all times 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, when the write recovery time

(tWR) is satisfied.

Power-down, as shown in Figure 46 on page 91, is entered when CKE is registered LOW

and all criteria in Table 25 on page 47 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 a

row is 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 precharge 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 require-

ments 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.

8000 S. Federal Way, P.O. Box 6, Boise, ID 83707-0006, Tel: 208-368-3900

www.micron.com/productsupport 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 respec-

tive owners. This data sheet contains minimum and maximum limits specified over the power supply and temperature range set forth

herein. Although considered final, these specifications are subject to change, as further product development and data characterization

sometimes occur.

256Mb: x4, x8, x16 DDR SDRAM

Operations

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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#

CommandValid2NOP

Address

CKE

DQS

Valid

tCKtCHtCL

tIS

tIH

tIS

tIStIH

tIH tIS

Enter 3

power-down

mode

Exit

power-down

mode

tREFC

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