256Mb: x16, x32 Mobile SDRAM
Features
Mobile SDRAM
MT48H16M16LF – 4 Meg x 16 x 4 banks
MT48H8M32LF – 2 Meg x 32 x 4 banks
Features
Table 1:
• Fully synchronous; all signals registered on positive
edge of system clock
• VDD/VDDQ = 1.70–1.95V
• Internal, pipelined operation; column address can
be changed every clock cycle
• Four internal banks for concurrent operation
• Programmable burst lengths: 1, 2, 4, 8, or
continuous page
• Auto precharge, includes concurrent auto precharge
• Auto refresh and self refresh modes
• LVTTL-compatible inputs and outputs
• On-chip temperature sensor to control refresh rate
• Partial-array self refresh (PASR)
• Deep power-down (DPD)
• Selectable output drive (DS)
• 64ms refresh period (8192 rows)
Options
Addressing
Configuration
Refresh count
Row addressing
Bank addressing
Column addressing
Table 2:
16 Meg x 16
8 Meg x 32
4 Meg x 16 x 4
banks
8K
8K (A[12:0])
4 (BA[1:0])
512 (A[8:0])
2 Meg x 32 x 4
banks
8K
4K (A[11:0])
4 (BA[1:0])
512 (A[8:0])
Key Timing Parameters
CL = CAS (READ) latency
Clock Rate
(MHz)
Access Time Data
Speed
Setup
Grade CL = 2 CL = 3 CL = 2 CL = 3 Time
-75
-8
104
100
133
125
8ns
9ns
6ns
7ns
1.5ns
2.5ns
Data
Hold
Time
1ns
1ns
Marking
• VDD/VDDQ
– 1.8V/1.8V
• Configuration
– 16 Meg x 16 (4 Meg x 16 x 4 banks)
– 8 Meg x 32 (2 Meg x 32 x 4 banks)
• Plastic “green” package
– 54-ball VFBGA (8mm x 9mm)
– 90-ball VFBGA (8mm x 13mm)
• Timing – cycle time
– 7.5ns at CL = 3
– 8ns at CL = 3
• Power
– Standard IDD2P/IDD7
– Low IDD2P/IDD7
• Operating temperature range
– Commercial (0° to +70°C)
– Industrial (–40°C to +85°C)
• Design revision
PDF:09005aef8219eeeb/Source: 09005aef8219eedd
256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
H
16M16
8M32
BF
B5
-75
-8
None
L
None
IT
:G
1
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2006 Micron Technology, Inc. All rights reserved.
Products and specifications discussed herein are subject to change by Micron without notice.
256Mb: x16, x32 Mobile SDRAM
Table of Contents
Table of Contents
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Functional Block Diagrams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Ball Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Ball Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Mode Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Extended Mode Register (EMR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Bank/Row Activation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
READs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
WRITEs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
Truth Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
Electrical Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
Timing Diagrams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
Package Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73
Revision History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75
PDF:09005aef8219eeeb/Source: 09005aef8219eedd
256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
2
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
List of Figures
List of Figures
Figure 1:
Figure 2:
Figure 3:
Figure 4:
Figure 5:
Figure 6:
Figure 7:
Figure 8:
Figure 9:
Figure 10:
Figure 11:
Figure 12:
Figure 13:
Figure 14:
Figure 15:
Figure 16:
Figure 17:
Figure 18:
Figure 19:
Figure 20:
Figure 21:
Figure 22:
Figure 23:
Figure 24:
Figure 25:
Figure 26:
Figure 27:
Figure 28:
Figure 29:
Figure 30:
Figure 31:
Figure 32:
Figure 33:
Figure 34:
Figure 35:
Figure 36:
Figure 37:
Figure 38:
Figure 39:
Figure 40:
Figure 41:
Figure 42:
Figure 43:
Figure 44:
Figure 45:
Figure 46:
Figure 47:
Figure 48:
Figure 49:
Figure 50:
Figure 51:
Figure 52:
Figure 53:
Figure 54:
256Mb Mobile SDRAM Part Numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
16 Meg x 16 SDRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
8 Meg x 32 SDRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
54-Ball FBGA (Top View) – 8mm x 9mm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
90-Ball VFBGA (Top View) – 8mm x 13mm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Mode Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
CAS Latency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
EMR Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Activating a Specific Row in a Specific Bank. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Example: Meeting tRCD (MIN) When 2 < tRCD (MIN)/tCK < 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
READ Command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Consecutive READ Bursts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Random READ Accesses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
READ-to-WRITE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
READ-to-WRITE with Extra Clock Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
READ-to-PRECHARGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
Terminating a READ Burst . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
WRITE Command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
WRITE Burst. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
WRITE-to-WRITE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Random WRITE Cycles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
WRITE-to-READ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
WRITE-to-PRECHARGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
Terminating a WRITE Burst . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
PRECHARGE Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
Power-Down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Clock Suspend During WRITE Burst . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
Clock Suspend During READ Burst . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
READ with Auto Precharge Interrupted by a READ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
READ with Auto Precharge Interrupted by a WRITE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
WRITE with Auto Precharge Interrupted by a READ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
WRITE with Auto Precharge Interrupted by a WRITE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
Typical Self Refresh Current vs. Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
Initialize and Load Mode Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
Power-Down Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
Clock Suspend Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56
Auto Refresh Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
Self Refresh Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58
READ – without Auto Precharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59
READ – with Auto Precharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
Single READ – without Auto Precharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61
Single READ – with Auto Precharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62
Alternating Bank Read Accesses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63
READ – Continuous Page Burst . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
READ – DQM Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65
WRITE – Without Auto Precharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66
WRITE – with Auto Precharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67
Single WRITE – Without Auto Precharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68
Single WRITE – with Auto Precharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69
Alternating Bank Write Accesses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70
WRITE – Continuous Page Burst . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71
WRITE – DQM Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72
54-Ball VFBGA (8mm x 9mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73
90-Ball VFBGA (8mm x 13mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74
PDF:09005aef8219eeeb/Source: 09005aef8219eedd
256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
3
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
List of Tables
List of Tables
Table 1:
Table 2:
Table 3:
Table 4:
Table 5:
Table 6:
Table 7:
Table 8:
Table 9:
Table 10:
Table 11:
Table 12:
Table 13:
Table 14:
Table 15:
Table 16:
Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Key Timing Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
VFBGA Ball Descriptions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Burst Definition Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Truth Table – Commands and DQM Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Truth Table – CKE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
Truth Table – Current State Bank n, Command to Bank n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
Truth Table – Current State Bank n, Command to Bank m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
DC Electrical Characteristics and Operating Conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
Electrical Characteristics and Recommended AC Operating Conditions . . . . . . . . . . . . . . . . . . . . . . .46
AC Functional Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
IDD Specifications and Conditions (x16) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
IDD Specifications and Conditions (x32) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
IDD7 – Self Refresh Current Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
Capacitance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
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256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
4
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
General Description
Figure 1:
256Mb Mobile SDRAM Part Numbering
Power
Example Part Number: MT48H8M32LFB5-75LIT
MT48
Mobile
Configuration
VDD/
VDDQ
Package
–
Temp. Revision
Speed
Revision
:G Design Revision
VDD/VDDQ
1.8V/1.8V
H
Operating Temp.
Commercial
IT
Industrial
Configuration
16 Meg x 16
16M16LF
8 Meg x 32
8M32LF
Power
Standard IDD2P/IDD7
L
Low IDD2P/IDD7
Speed Grade
Package
BF
8 x 9 VFBGA (lead-free)
-75
tCK
= 7.5ns
B5
8 x 13 VFBGA (lead-free)
-8
tCK
= 8.0ns
General Description
The Micron® 256Mb Mobile SDRAM is a high-speed CMOS, dynamic random-access
memory containing 268,435,456-bits. It is internally configured as a quad-bank DRAM
with a synchronous interface (all signals are registered on the positive edge of the clock
signal, CLK). Each of the x16’s 67,108,864-bit banks is organized as 8192 rows by 512 columns by 16 bits. Each of the x32’s 67,108,864-bit banks is organized as 4096 rows by 512
columns by 32 bits.
Read and write accesses to the SDRAM are burst oriented; accesses start at a selected
location and continue for a programmed number of locations in a programmed
sequence. Accesses begin with the registration of an ACTIVE command, which is then
followed by a READ or WRITE command. The address bits registered coincident with the
ACTIVE command are used to select the bank and row to be accessed. The address bits
registered coincident with the READ or WRITE command are used to select the starting
column location for the burst access.
The SDRAM provides for programmable read or write burst lengths (BLs) of 1, 2, 4, or 8
locations, or continuous page burst, with a read burst terminate option. An auto precharge function may be enabled to provide a self-timed row precharge that is initiated at
the end of the burst sequence.
The 256Mb SDRAM uses an internal pipelined architecture to achieve high-speed operation. It also allows the column address to be changed on every clock cycle to achieve a
high-speed, fully random access. Precharging one bank while accessing one of the other
three banks will hide the precharge cycles and provide seamless high-speed, randomaccess operation.
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5
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
Functional Block Diagrams
The 256Mb SDRAM is designed to operate in 1.8V low-power memory systems. An auto
refresh mode is provided, along with a power-saving deep power-down mode. All inputs
and outputs are LVTTL-compatible.
SDRAM offers substantial advances in DRAM operating performance, including the ability to synchronously burst data at a high data rate with automatic column-address generation, the ability to interleave between internal banks in order to hide precharge time,
and the capability to randomly change column addresses on each clock cycle during a
burst access.
Functional Block Diagrams
Figure 2:
16 Meg x 16 SDRAM
BA1
0
0
1
1
CKE
BA0
0
1
0
1
Bank
0
1
2
3
CLK
CONTROL
LOGIC
COMMAND
DECODE
CS#
WE#
CAS#
RAS#
Bank3
Bank2
Bank1
EXT MODE
REGISTER
MODE REGISTER
REFRESH 13
COUNTER
15
ROWADDRESS
MUX
13
13
BANK0
ROWADDRESS
LATCH
&
DECODER
8192
BANK0
MEMORY
ARRAY
(8192 x 512 x 16)
2
UDQM,
LDQM
Sense amplifiers
16
8192
I/O GATING
DQM MASK LOGIC
READ DATA LATCH
WRITE DRIVERS
2
A[12:0],
BA[1:0]
15
ADDRESS
REGISTER
2
BANK
CONTROL
LOGIC
256
(x16)
2
DATA
OUTPUT
REGISTER
16
16
DQ[15:0]
DATA
INPUT
REGISTER
COLUMN
DECODER
9
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256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
COLUMNADDRESS
COUNTER/
LATCH
9
6
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
Functional Block Diagrams
Figure 3:
8 Meg x 32 SDRAM
BA1
0
0
1
1
CKE
BA0
0
1
0
1
Bank
0
1
2
3
CLK
CONTROL
LOGIC
COMMAND
DECODE
CS#
WE#
CAS#
RAS#
BANK3
BANK2
BANK1
EXT MODE
REGISTER
MODE REGISTER
REFRESH 13
COUNTER
14
ROWADDRESS
MUX
12
12
BANK0
ROWADDRESS
LATCH
&
DECODER
4096
BANK0
MEMORY
ARRAY
(4096 x 512 x 32)
4
DQM[3:0]
SENSE AMPLIFIERS
32
4096
I/O GATING
DQM MASK LOGIC
READ DATA LATCH
WRITE DRIVERS
2
A[11:0],
BA[1:0]
14
ADDRESS
REGISTER
2
BANK
CONTROL
LOGIC
DATA
OUTPUT
REGISTER
32
32
512
(x32)
4
DQ[31:0]
DATA
INPUT
REGISTER
COLUMN
DECODER
9
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COLUMNADDRESS
COUNTER/
LATCH
9
7
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©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
Ball Assignments
Ball Assignments
Figure 4:
54-Ball FBGA (Top View) – 8mm x 9mm
1
2
3
VSS
DQ15
DQ14
4
5
6
7
8
9
VSSQ
VDDQ
DQ0
VDD
DQ13
VDDQ
VSSQ
DQ2
DQ1
DQ12
DQ11
VSSQ
VDDQ
DQ4
DQ3
DQ10
DQ9
VDDQ
VSSQ
DQ6
DQ5
DQ8
DNU
VSS
VDD
LDQM
DQ7
UDQM
CLK
CKE
CAS#
RAS#
WE#
A12
A11
A9
BA0
BA1
CS#
A8
A7
A6
A0
A1
A10
VSS
A5
A4
A3
A2
VDD
A
B
C
D
E
F
G
H
J
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Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
Ball Assignments
Figure 5:
90-Ball VFBGA (Top View) – 8mm x 13mm
1
2
3
DQ26
DQ24
DQ28
4
5
6
7
8
9
VSS
VDD
DQ23
DQ21
VDDQ
VSSQ
VDDQ
VSSQ
DQ19
VSSQ
DQ27
DQ25
DQ22
DQ20
VDDQ
VSSQ
DQ29
DQ30
DQ17
DQ18
VDDQ
VDDQ
DQ31
NC
NC
DQ16
VSSQ
VSS
DQM3
A3
A2
DQM2
VDD
A4
A5
A6
A10
A0
A1
A7
A8
NC
NC
BA1
A11
CLK
CKE
A9
BA0
CS#
RAS#
DQM1
DNU
NC
CAS#
WE#
DQM0
VDDQ
DQ8
VSS
VDD
DQ7
VSSQ
VSSQ
DQ10
DQ9
DQ6
DQ5
VDDQ
VSSQ
DQ12
DQ14
DQ1
DQ3
VDDQ
DQ11
VDDQ
VSSQ
VDDQ
VSSQ
DQ4
DQ13
DQ15
VSS
VDD
DQ0
DQ2
A
B
C
D
E
F
G
H
J
K
L
M
N
P
R
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9
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
Ball Descriptions
Ball Descriptions
Table 3:
VFBGA Ball Descriptions
54-Ball VFBGA 90-Ball VFBGA
Symbol
Type
Description
Clock: CLK is driven by the system clock. All SDRAM input signals
are sampled on the positive edge of CLK. CLK also increments
the internal burst counter and controls the output registers.
Clock enable: CKE activates (HIGH) and deactivates (LOW) the
CLK signal. Deactivating the clock provides precharge powerdown and SELF REFRESH operation (all banks idle), ACTIVE
power-down (row active in any bank), Deep power-down (all
banks idle), or CLOCK SUSPEND operation (burst/access in
progress). CKE is synchronous except after the device enters
power-down and self refresh modes, where CKE becomes
asynchronous until after exiting the same mode. The input
buffers, including CLK, are disabled during power-down and self
refresh modes, providing low standby power.
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.
Command inputs: RAS#, CAS#, and WE# (along with CS#) define
the command being entered.
Input/output mask: DQM is sampled HIGH and is an input mask
signal for write accesses and an output enable signal for read
accesses. Input data is masked during a WRITE cycle. The output
buffers are placed in a High-Z state (two-clock latency) during a
READ cycle. For the x16, LDQM corresponds to DQ[7:0] and
UDQM corresponds to DQ[16:8]. For the x32, DQM0 corresponds
to DQ[7:0], DQM1 corresponds to DQ[15:8], DQM2 corresponds
to DQ[23:16], and DQM3 corresponds to DQ[31:24]. DQM[3:0]
(or LDQM and UDQM if x16) are considered same state when
referenced as DQM. DQM loading is designed to match that of
DQ balls.
Bank address input(s): BA[1:0] define to which bank the ACTIVE,
READ, WRITE, or PRECHARGE command is being applied. These
balls also provide the op-code during a LOAD MODE REGISTER
(LMR) command. BA[1:0] become “Don’t Care” when registering
an ALL BANK PRECHARGE (A10 HIGH).
Address inputs: A[12:0] are sampled during the ACTIVE
command (row-address A[12:0] and READ/WRITE command
(column-address A[8:0] (x32); column-address A[8:0] (x16); with
A10 defining auto precharge) to select one location out of the
memory array in the respective bank. A10 is sampled during a
PRECHARGE command to determine if all banks are to be
precharged (A10 HIGH) or bank selected by BA[1:0]. The address
inputs also provide the op-code during a LMR command.
F2
J1
CLK
Input
F3
J2
CKE
Input
G9
J8
CS#
Input
F7, F8, F9
K7, J9, K8
Input
F1, E8
K9, K1, F8, F2
CAS#,
RAS#, WE#
UDQM
LDQM,
DQM[33:0]
Input
G7, G8
J7, H8
BA[1:0]
Input
H7, H8, J8, J7,
J3, J2, H3, H2,
H1, G3, H9, G2,
G1
G8, G9, F7, F3,
G1, G2, G3, H1,
H2, J3, G7, H9
A[12:0]
Input
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10
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
Ball Descriptions
Table 3:
VFBGA Ball Descriptions (Continued)
54-Ball VFBGA 90-Ball VFBGA
Symbol
Type
A8, B9, B8, C9,
C8, D9, D8, E9,
E1, D2, D1, C2,
C1, B2, B1, A2
DQ[31:0]
I/O
VDDQ
Supply
DQ power: Provide isolated power to DQ for improved noise
immunity.
VSSQ
Supply
DQ ground: Provide isolated ground to DQ for improved noise
immunity.
VDD
VSS
NC
Supply
Supply
–
DNU
Input
Core power supply.
Ground.
Internally not connected: These could be left unconnected, but
it is recommended they be connected to VSS.
E2 is a TEST pin that must be tied to VSS or VSSQ in normal
operation.
A7, B3, C7, D3
A3, B7, C3, D7
A9, E7, J9
A1, E3, J1
–
E2
R8, N7, R9, N8,
P9, M8, M7, L8,
L2, M3, M2, P1,
N2, R1, N3, R2,
E8, D7, D8, B9,
C8, A9, C7, A8,
A2, C3, A1, C2,
B1, D2, D3, E2
B2, B7, C9, D9,
E1, L1, M9, N9,
P2, P7
B8, B3, C1, D1,
E9, L9, M1, N1,
P3, P8
A7, F9, L7, R7
A3, F1, L3, R3
E3, E7, H3, H7,
K3
K2
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Description
Data input/output: Data bus.
11
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
Functional Description
Functional Description
In general, a 256Mb SDRAM is quad-bank DRAM that operates at 1.8V and includes a
synchronous interface (all signals are registered on the positive edge of the clock signal,
CLK).
Read and write accesses to the SDRAM are burst oriented; accesses start at a selected
location and continue for a programmed number of locations in a programmed
sequence. Accesses begin with the registration of an ACTIVE command, which is then
followed by a READ or WRITE command. The address bits registered coincident with the
ACTIVE command are used to select the bank and row to be accessed (BA[1:0] select the
bank, A[12:0] select the row for x16, and A[11:0] select the row for x32). The address bits
(A[8:0] for x16 and A[8:0] for x32) registered coincident with the READ or WRITE command are used to select the starting column location for the burst access.
Prior to normal operation, the SDRAM must be initialized. The following sections provide detailed information covering device initialization, register definition, command
descriptions, and device operation.
Initialization
SDRAM must be powered up and initialized in a predefined manner. Operational procedures other than those specified may result in undefined operation. The initialization for
mobile SDRAM is as follows.
1. Simultaneously apply power to VDD and VDDQ.
2. After power supplies have settled, apply a stable clock signal. Stable clock is defined as
a signal cycling within timing constraints specified for the clock pin.
3. Wait at least 100µs. During this period NOP or COMMAND INHIBIT commands
should be applied. No other command other than NOP or COMMAND INHIBIT is
allowed during this period.
4. Preform a PRECHARGE ALL command to place the SDRAM into an all banks idle
state.
5. Wait at least tRP time. During this time NOP or COMMAND INHIBIT commands must
be applied.
6. Issue an AUTO REFRESH command.
7. Wait at least tRFC time, during which only NOP or COMMAND INHIBIT commands
are allowed.
8. Issue an Auto Refresh command.
9. Wait at least tRFC time, during which only NOP or COMMAND INHIBIT commands
are allowed.
10. Issue a LOAD MODE REGISTER command with BA1=0, and BA0=0, to program the
mode register with desired values.
11. Wait tMRD time. Only NOP or COMMAND INHIBIT commands may be applied during this time.
12. Issue a LOAD MODE REGISTER command with BA1 = 1, and BA0 = 0, to program the
extended mode register with desired values.
13. Wait tMRD time. Only NOP or COMMAND INHIBIT commands may be applied during this time.
The Mobile SDRAM is now initialized and can accept any valid command.
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©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
Register Definition
Register Definition
Mode Register
There are two mode registers in the component: mode register and extended mode register (EMR). The mode register is illustrated in Figure 6 on page 14. The mode register is
used to define the specific mode of operation of the SDRAM. This definition includes the
selection of a burst length (BL), a burst type, a CAS latency (CL), an operating mode and
a write burst mode, as shown in Figure 6 on page 14. The mode register is programmed
via the LMR command and will retain the stored information until it is programmed
again or the device loses power.
Mode register bits M[2:0] specify the BL, M3 specifies the type of burst, M[6:4] specify
the CL, M[8:7] specify the operating mode, M9 specifies the write burst mode, and
M[11:10] should be set to zero.
The mode register must be loaded when all banks are idle, and the controller must wait
MRD before initiating the subsequent operation. Violating either of these requirements
will result in unspecified operation.
t
Burst Length (BL)
Read and write accesses to the SDRAM are burst oriented, with the BL being programmable, as shown in Figure 6 on page 14. The BL determines the maximum number of
column locations that can be accessed for a given READ or WRITE command. BL = 1, 2,
4, 8 locations are available for both the sequential and the interleaved burst types, and a
continuous page burst is available for the sequential type. The continuous page burst is
used in conjunction with the BURST TERMINATE command to generate arbitrary burst
lengths.
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 BL 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[8:1] when BL = 2, A[8:2] when BL = 4, and A[8:3] when BL = 8. The remaining (least
significant) address bit(s) is (are) used to select the starting location within the block.
Continuous page bursts wrap within the page if the boundary is reached.
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 BL, the burst type, and the
starting column address, as shown in Table 4 on page 15.
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13
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
Register Definition
Figure 6:
Mode Register Definition
BA1 BA0 A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1
A0
Address Bus
M14 M13 M12 M11 M10 M9 M8 M7 M6 M5 M4 M3 M2 M1 M0
14
0
13 12 11 10
9
8
7
6 5
4
0
Reserved WB OP Mode CAS Latency
0
3
2
1
BT Burst Length
Program
M12, M11, M10 = “0, 0, 0”
to ensure compatibility
with future devices.
Burst Length
M2 M1 M0
1
M3 = 1
0
0
1
1
0
0
1
2
2
0
1
0
4
4
Reserved
0
1
1
8
8
0
0
Reserved
Reserved
1
0
Extended mode register
1
1
1
Reserved
1
0
1
Reserved
Reserved
1
1
0
Reserved
Reserved
1
1
1
Continuous
Reserved
M9
Write Burst Mode
0
Programmed burst length
1
Single location access
M3
M8 M7
0
0
M[6:0]
Valid
–
–
–
Burst Type
Operating Mode
0
Sequential
Normal operation
1
Interleaved
All other states reserved
M6 M5 M4
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256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
M3 = 0
0
M14 M13 Mode Register Definintion
0
0
Base mode register
0
Mode
Register (Mx)
14
CAS Latency
0
0
0
Reserved
0
0
1
Reserved
0
1
0
2
0
1
1
3
1
0
0
Reserved
1
0
1
Reserved
1
1
0
Reserved
1
1
1
Reserved
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
Register Definition
Table 4:
Burst Definition Table
Order of Accesses Within a Burst
Burst Length
Starting Column Address
2
4
8
A2
0
0
0
0
1
1
1
1
Continuous
Page
A1
0
0
1
1
A1
0
0
1
1
0
0
1
1
n = A[8:0]
A0
0
1
A0
0
1
0
1
A0
0
1
0
1
0
1
0
1
Type = Sequential
Type = Interleaved
0-1
1-0
0-1
1-0
0-1-2-3
1-2-3-0
2-3-0-1
3-0-1-2
0-1-2-3
1-0-3-2
2-3-0-1
3-2-1-0
0-1-2-3-4-5-6-7
1-2-3-4-5-6-7-0
2-3-4-5-6-7-0-1
3-4-5-6-7-0-1-2
4-5-6-7-0-1-2-3
5-6-7-0-1-2-3-4
6-7-0-1-2-3-4-5
7-0-1-2-3-4-5-6
Cn, Cn + 1,
Cn + 2
Cn + 3,
Cn + 4…,
…Cn - 1,
Cn…
0-1-2-3-4-5-6-7
1-0-3-2-5-4-7-6
2-3-0-1-6-7-4-5
3-2-1-0-7-6-5-4
4-5-6-7-0-1-2-3
5-4-7-6-1-0-3-2
6-7-4-5-2-3-0-1
7-6-5-4-3-2-1-0
Not supported
CAS Latency (CL)
The CL is the delay, in clock cycles, between the registration of a READ command and
the availability of the first piece of output data. The latency can be set to two or three
clocks.
If a READ command is registered at clock edge n, and the latency is m clocks, the data
will be available by clock edge n + m. The DQs will start driving as a result of the clock
edge one cycle earlier (n + m - 1), and provided that the relevant access times are met,
the data will be valid by clock edge n + m. For example, assuming that the clock cycle
time is such that all relevant access times are met, if a READ command is registered at T0
and the latency is programmed to two clocks, the DQs will start driving after T1 and the
data will be valid by T2, as shown in Figure 7 on page 16.
Reserved states should not be used as unknown operation or incompatibility with future
versions may result.
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Register Definition
Figure 7:
CAS Latency
T0
T1
T2
T3
READ
NOP
NOP
CLK
COMMAND
tLZ
tOH
DOUT
DQ
tAC
CL = 2
T0
T1
T2
T3
T4
READ
NOP
NOP
NOP
CLK
COMMAND
tLZ
tOH
DOUT
DQ
tAC
CL = 3
DON’T CARE
UNDEFINED
Operating Mode
The normal operating mode is selected by setting M7 and M8 to zero; the other combinations of values for M7 and M8 are reserved for future use.
Reserved states should not be used as unknown operation or incompatibility with future
versions may result.
Write Burst Mode
When M9 = 0, the BL programmed via M[2:0] applies to both READ and WRITE bursts;
when M9 = 1, the programmed BL applies to READ bursts, but write accesses are singlelocation accesses.
Extended Mode Register (EMR)
The low-power EMR controls the functions beyond those controlled by the mode register. These additional functions are special features of the mobile device. They include
temperature-compensated self refresh (TCSR) control, partial-array self refresh (PASR),
and output drive strength.
The low-power EMR is programmed via the MODE REGISTER SET command and
retains the stored information until it is programmed again or the device loses power.
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Register Definition
Figure 8:
EMR Definition
BA1 BA0 A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0
E14 E13 E12 E11 E10 E9
E8
E7
E6
14
1
8
7
6 5
DS
13 12
0
11 10
9
set to “0”
E14 E13 Mode Register Definintion
0 Standard mode register
0
1 Reserved
0
0 Extended mode register
1
1 Reserved
1
E12 E11 E10 E9
0
0
0
0
–
–
–
–
E8
0
–
E7
0
–
E6–E0
Valid
–
E6
0
0
E5
0
1
E5
E4
E3
4
3
TCSR1
E2
2
E1
Address Bus
E0
0
1
PASR
Extended Mode
Register
Driver Strength
Full strength driver
Half strength driver
1
0
Quarter strength driver
1
1
Eighth strength driver
Normal operation
All other states reserved
E2
0
0
E1
0
0
E0
0
1
Partial Array Self Refresh Coverage
Full array
Half array
0
1
0
Quarter array
0
1
1
1
0
0
1
0
1
Reserved
Reserved
One-eighth array
1
1
0
One-sixteenth array
1
1
1
Reserved
Notes: 1. On-die temperature sensor is used in place of TCSR. Setting these bits will have no effect.
The EMR must be loaded when all banks are idle and no bursts are in progress, and the
controller must wait the specified time before initiating any subsequent operation. Violating either of these requirements results in unspecified operation. Once the values are
entered, the EMR settings will be retained even after exiting deep power-down mode.
Temperature-Compensated Self Refresh (TCSR)
On this version of the Mobile SDR SDRAM, a temperature sensor is implemented for
automatic control of the self refresh oscillator on the device. Therefore, it is recommended not to program or use the temperature-compensated self refresh control bits in
the extended mode register.
Programming of the TCSR bits has no effect on the device. The self refresh oscillator will
continue refresh at the factory programmed optimal rate for the device temperature.
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Register Definition
Partial-Array Self Refresh (PASR)
For further power savings during self refresh, the partial-array self refresh (PASR) feature
allows the controller to select the amount of memory that will be refreshed during self
refresh. The following refresh options are available.
1. All banks (banks 0, 1, 2, and 3).
2. Two banks (banks 0 and 1; BA1 = 0).
3. One bank (bank 0; BA1 = BA0 = 0).
4. Half bank (bank 0; BA1 = BA0 = row address MSB = 0).
5. Quarter bank (bank 0; BA1 = BA0; row address MSB = row address MSB -1 = 0).
WRITE and READ commands occur to any bank selected during standard operation, but
only the selected banks in PASR will be refreshed during self refresh. It is important to
note that data in banks 2 and 3 will be lost when the two-bank option is used.
Driver Strength
Bits E5 and E6 of the EMR can be used to select the driver strength of the DQ outputs.
This value should be set according to the application’s requirements.
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Commands
Commands
Table 5 provides a quick reference of available commands. This is followed by a written
description of each command. Three additional truth tables appear following “Operations” on page 23. These tables provide current state/next state information.
Table 5:
Truth Table – Commands and DQM Operation
Notes 1 and 2 apply to all commands
Name (Function)
CS#
COMMAND INHIBIT (NOP)
NO OPERATION (NOP)
ACTIVE (Select bank and activate row)
READ (Select bank and column, and start READ burst)
WRITE (Select bank and column, and start WRITE burst)
BURST TERMINATE or deep power-down
(Enter deep power-down mode)
PRECHARGE (Deactivate row in bank or banks)
AUTO REFRESH or SELF REFRESH
(Enter self refresh mode)
LOAD MODE REGISTER
Write enable/output enable
Write inhibit/output High-Z
RAS# CAS#
WE#
DQM
ADDR
DQs
Notes
H
L
L
L
L
L
X
H
L
H
H
H
X
H
H
L
L
H
X
H
H
H
L
L
X
X
X
L/H
L/H
X
X
X
Bank/Row
Bank/Col
Bank/Col
X
X
X
X
X
Valid
X
4
4
5
6
6
3, 7, 8
L
L
L
L
H
L
L
H
X
X
Code
X
X
X
9
10, 11
L
X
X
L
X
X
L
X
X
L
X
X
X
L
H
Op-Code
X
X
X
Active
High-Z
12
Notes: 1. CKE is HIGH for all commands shown except SELF REFRESH and deep power-down.
2. All states and sequences not shown are reserved and/or illegal.
3. The purpose of the BURST TERMINATE command is to stop a data burst, thus the command
could coincide with data on the bus. However, the DQs column reads a don’t care state to
illustrate that the BURST TERMINATE command can occur when there is no data present.
4. DESELECT and NOP are functionally interchangeable.
5. BA[1:0] provide bank address and A[12:0] provide row address.
6. BA[1:0] provide bank address; A[9:0] provide column address; A10 HIGH enables the auto
precharge feature (nonpersistent), and A10 LOW disables the auto precharge feature.
7. 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.
8. This command is a BURST TERMINATE if CKE is HIGH, deep power-down if CKE is LOW.
9. A10 LOW: BA[1:0] determine which bank is precharged. A10 HIGH: all banks are precharged and BA[1:0] are “Don’t Care.”
10. This command is AUTO REFRESH if CKE is HIGH, SELF REFRESH if CKE is LOW.
11. Internal refresh counter controls row addressing; all inputs and I/Os are “Don’t Care”
except for CKE.
12. BA[1:0] select either the standard mode register or the extended mode register (BA0 = 0,
BA1 = 0 select the standard mode register; BA0 = 0, BA1 = 1 select extended mode register;
other combinations of BA[1:0] are reserved.) A[12:0] provide the op-code to be written to
the selected mode register.
COMMAND INHIBIT
The COMMAND INHIBIT function prevents new commands from being executed by the
SDRAM, regardless of whether the CLK signal is enabled. The SDRAM is effectively deselected. Operations already in progress are not affected.
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Commands
NO OPERATION (NOP)
The NO OPERATION (NOP) command is used to perform a NOP to an SDRAM which is
selected (CS# is LOW). 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 register is loaded via inputs A[12:0] and BA[1:0]. (See “Mode Register” on page
13.) The LMR and LOAD EXTENDED MODE REGISTER (LEMR) commands can only be
issued when all banks are idle, and a subsequent executable command cannot be issued
until tMRD is met.
ACTIVE
The ACTIVE command is used to open (or activate) a row in a particular bank for a subsequent access. The value on the BA[1:0] inputs selects the bank, and the address provided selects the row. This row remains active (or open) for accesses until a PRECHARGE
command is issued to that bank. A PRECHARGE command must be issued before opening a different row in the same bank.
READ
The READ command is used to initiate a burst read access to an active row. The value on
the BA[1:0] inputs selects the bank, and the address provided selects the starting column
location. The value on input A10 determines whether or not auto precharge is used. If
auto precharge is selected, the row being accessed will be precharged at the end of the
read burst; if auto precharge is not selected, the row will remain open for subsequent
accesses. Read data appears on the DQs subject to the logic level on the DQM inputs two
clocks earlier. If a given DQM signal was registered HIGH, the corresponding DQs will be
High-Z two clocks later; if the DQM signal was registered LOW, the DQs will provide valid
data.
WRITE
The WRITE command is used to initiate a burst write access to an active row. The value
on the BA[1:0] inputs selects the bank, and the address provides the starting column
location. The value on input A10 determines whether or not auto precharge is used. If
auto precharge is selected, the row being accessed will be precharged at the end of the
write burst; if auto precharge is not selected, the row will remain open for subsequent
accesses. Input data appearing on the DQs is written to the memory array subject to the
DQM input logic level appearing coincident with the data. If a given DQM signal is registered LOW, the corresponding data will be written to memory; if the DQM signal is registered HIGH, the corresponding data inputs will be ignored, and a write will not be
executed to that byte/column location.
PRECHARGE
The PRECHARGE command is used to deactivate the open row in a particular bank or
the open row in all banks. The bank(s) will be available for a subsequent row access a
specified time (tRP) after the precharge command is issued. 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 BA[1:0] select the bank. Otherwise BA[1:0] 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.
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Commands
BURST TERMINATE
The BURST TERMINATE command is used to truncate either fixed-length or continuous
page bursts. The most recently registered READ or WRITE command prior to the BURST
TERMINATE command will be truncated, as shown in “Operations” on page 23.
AUTO REFRESH
AUTO REFRESH is used during normal operation of the SDRAM and is analogous to
CAS#-BEFORE-RAS# (CBR) refresh in conventional DRAM. This command is non persistent, so it must be issued each time a refresh is required. All active banks must be PRECHARGED prior to issuing an AUTO REFRESH command. The AUTO REFRESH
command should not be issued until the minimum tRP has been met after the PRECHARGE command, as shown in “Operations” on page 23.
The addressing is generated by the internal refresh controller. This makes the address
bits “Don’t Care” during an AUTO REFRESH command. The 256Mb SDRAM requires
8192 AUTO REFRESH cycles every 64ms (tREF). Providing a distributed AUTO REFRESH
command every 7.8125µs will meet the refresh requirement and ensure that each row is
refreshed. Alternatively, 8192 AUTO REFRESH commands can be issued in a burst at the
minimum cycle rate (tRFC), once every 64ms.
SELF REFRESH
The SELF REFRESH command can be used to retain data in the SDRAM, even if the rest
of the system is powered down. When in the self refresh mode, the SDRAM retains data
without external clocking. The SELF REFRESH command is initiated like an AUTO
REFRESH command, except CKE is disabled (LOW). Once the SELF REFRESH command
is registered, all the inputs to the SDRAM become “Don’t Care” with the exception of
CKE, which must remain LOW.
Once self refresh mode is engaged, the SDRAM provides its own internal clocking, causing it to perform its own auto refresh cycles. The SDRAM must remain in self refresh
mode for a minimum period equal to tRAS and may remain in self refresh mode for an
indefinite period beyond that.
The procedure for exiting self refresh requires a sequence of commands. First, CLK must
be stable (stable clock is defined as a signal cycling within timing constraints specified
for the clock ball) prior to CKE going back HIGH. Once CKE is HIGH, the SDRAM must
have NOP commands issued (a minimum of two clocks) for tXSR because time is
required for the completion of any internal refresh in progress.
Upon exiting the self refresh mode, AUTO REFRESH commands must be issued every
7.8125µs or less as both SELF REFRESH and AUTO REFRESH utilize the row refresh
counter.
Auto Precharge
Auto precharge is a feature which performs the same individual-bank precharge function described above, 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, except
in the continuous page burst mode, where auto precharge does not apply. Auto precharge is non persistent in that it is either enabled or disabled for each individual READ
or WRITE command.
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Commands
Auto precharge ensures that the precharge is initiated at the earliest valid stage within a
burst. The user must not issue another command to the same bank until the precharge
time (tRP) is completed. This is determined as if an explicit PRECHARGE command was
issued at the earliest possible time, as described for each burst type in “Operations” on
page 23.
Deep Power-Down
Deep power-down is an operating mode used to achieve maximum power reduction by
eliminating the power to the memory array. Data will not be retained once the device
enters deep power-down mode.
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Operations
Operations
Bank/Row Activation
Before any READ or WRITE commands can be issued to a bank within the SDRAM, a row
in that bank must be “opened.” This is accomplished via the ACTIVE command, which
selects both the bank and the row to be activated (see Figure 9).
After opening a row (issuing 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 125 MHz clock (8ns period)
results in 2.5 clocks, rounded to 3. This is reflected in Figure 10 on page 24, which covers
any case where 2 < tRCD (MIN)/tCK ≤ 3. (The same procedure is used to convert other
specification limits from time units to clock cycles.)
A subsequent ACTIVE command to a different row in the same bank can only be issued
after the previous active row has been “closed” (precharged). The minimum time 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
t
RRD.
Figure 9:
Activating a Specific Row in a Specific Bank
CLK
CKE
HIGH
CS#
RAS#
CAS#
WE#
A0–A11
BA0, BA1
ROW
ADDRESS
BANK
ADDRESS
DON´T CARE
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Operations
Figure 10:
Example: Meeting tRCD (MIN) When 2 < tRCD (MIN)/tCK < 3
T0
T1
T2
T3
CLK
tCK
tCK
COMMAND
ACTIVE
NOP
tCK
NOP
READ or
WRITE
tRCD (MIN)
DON’T CARE
READs
READ bursts are initiated with a READ command, as shown in Figure 11.
The starting column and bank addresses are provided with the READ command, and
auto precharge is either enabled or disabled for that burst access. If auto precharge is
enabled, the row being accessed is precharged at the completion of the burst. For the
generic READ commands used in the following illustrations, auto precharge is disabled.
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 by the next positive clock edge. Figure 7 on page 16 shows general timing for each possible CL setting.
Figure 11:
READ Command
CLK
CKE
HIGH
CS#
RAS#
CAS#
WE#
A0–A8
COLUMN
ADDRESS
A9, A11
ENABLE AUTO PRECHARGE
A10
DISABLE AUTO PRECHARGE
BA0, BA1
BANK
ADDRESS
DON’T CARE
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Operations
Upon completion of a burst, assuming no other commands have been initiated, the DQs
will go High-Z. A continuous page burst will proceed until terminated (at the end of the
page, it will wrap to the start address and continue).
Data from any READ burst may be truncated with a subsequent READ command, and
data from a fixed-length READ burst may be immediately followed by data from a 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 that is being truncated. The new READ command should be issued x cycles before the clock edge at which the last desired data element is valid, where x = CL - 1.
Figure 7 on page 16 shows for CL of two and three; data element n + 3 is either the last of
a burst of four or the last desired of a longer burst. The 256Mb SDRAM uses a pipelined
architecture. A READ command can be initiated on any clock cycle following a previous
READ command. Full-speed random read accesses can be performed to the same bank,
as shown in Figure 12 on page 25, or each subsequent READ may be performed to a different bank.
Figure 12:
Consecutive READ Bursts
T0
T1
T2
T3
T4
T5
T6
CLK
COMMAND
READ
ADDRESS
BANK,
COL n
NOP
NOP
NOP
NOP
READ
NOP
X = 1 cycle
BANK,
COL b
DOUT
n+2
DOUT
n+1
DOUT
n
DQ
DOUT
n+3
DOUT
b
CL = 2
T0
T1
T2
T3
T4
T5
T6
T7
CLK
COMMAND
READ
ADDRESS
BANK,
COL n
NOP
NOP
NOP
READ
NOP
NOP
NOP
X = 2 cycles
BANK,
COL b
DOUT
n
DQ
DOUT
n+1
DOUT
n+2
DOUT
n+3
DOUT
b
CL = 3
DON’T CARE
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Operations
Note:
Figure 13:
Each READ command may be to either bank. DQM is LOW.
Random READ Accesses
T0
T1
T2
T3
T4
T5
CLK
COMMAND
READ
READ
READ
READ
ADDRESS
BANK,
COL n
BANK,
COL a
BANK,
COL x
BANK,
COL m
DOUT
n
DQ
NOP
NOP
DOUT
x
DOUT
a
DOUT
m
CL = 2
T0
T1
T2
T3
T4
T5
T6
CLK
COMMAND
READ
READ
READ
READ
ADDRESS
BANK,
COL n
BANK,
COL a
BANK,
COL x
BANK,
COL m
DOUT
n
DQ
NOP
NOP
DOUT
a
DOUT
x
NOP
DOUT
m
CL = 3
DON’T CARE
Note:
Each READ command may be to either bank. DQM is LOW.
Data from any READ burst may be truncated with a subsequent WRITE command, and
data from a fixed-length READ burst may be immediately followed by data from a
WRITE command (subject to bus turnaround limitations). The WRITE burst may be
initiated on the clock edge immediately following the last (or last desired) data element
from the READ burst, provided that I/O contention can be avoided. In a given system
design, there may be a possibility that the device driving the input data will go Low-Z
before the SDRAM DQs go High-Z. In this case, at least a single-cycle delay should occur
between the last read data and the WRITE command.
The DQM input is used to avoid I/O contention, as shown in Figure 14 on page 27 and
Figure 15 on page 28. The DQM signal must be asserted (HIGH) at least two clocks prior
to the WRITE command (DQM latency is two clocks for output buffers) to suppress dataout from the READ. Once the WRITE command is registered, the DQs will go High-Z (or
remain High-Z), regardless of the state of the DQM signal, provided the DQM was active
on the clock just prior to the WRITE command that truncated the READ command. If
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Operations
not, the second WRITE will be an invalid WRITE. For example, if DQM was LOW during
T4 (as in Figure 15 on page 28) then the WRITEs at T5 and T7 would be valid, while the
WRITE at T6 would be invalid.
The DQM signal must be de-asserted prior to the WRITE command (DQM latency is
zero clocks for input buffers) to ensure that the written data is not masked. Figure 12 on
page 25 shows the case where the clock frequency allows for bus contention to be
avoided without adding a NOP cycle, and Figure 13 on page 26 shows the case where the
additional NOP is needed.
A fixed-length READ burst may be followed by, or truncated with, a PRECHARGE command to the same bank (provided that auto precharge was not activated). The PRECHARGE command should be issued x cycles before the clock edge at which the last
desired data element is valid, where x = CL - 1. This is shown in Figure 16 on page 28 for
each possible CL; data element n + 3 is either the last of a burst of four or the last desired
of a longer burst. Following the PRECHARGE command, a subsequent command to the
same bank cannot be issued until tRP is met. Note that part of the row precharge time is
hidden during the access of the last data element(s).
In the case of a fixed-length burst being executed to completion, a PRECHARGE command issued at the optimum time (as described above) provides the same operation
that would result from the same fixed-length burst with auto precharge. The disadvantage of the PRECHARGE command is that it requires that the command and address
buses be available at the appropriate time to issue the command; the advantage of the
PRECHARGE command is that it can be used to truncate fixed-length or continuous
page bursts.
Figure 14:
READ-to-WRITE
T0
T1
T2
T3
T4
CLK
DQM
COMMAND
READ
ADDRESS
BANK,
COL n
NOP
NOP
NOP
WRITE
BANK,
COL b
tCK
tHZ
DOUT n
DQ
DIN b
tDS
DON’T CARE
Note:
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CL = 3. The READ command may be to any bank, and the WRITE command may be to any
bank. If a burst of one is used, then DQM is not required.
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Operations
Figure 15:
READ-to-WRITE with Extra Clock Cycle
T0
T1
T2
T3
T4
T5
CLK
DQM
COMMAND
READ
ADDRESS
BANK,
COL n
NOP
NOP
NOP
NOP
WRITE
BANK,
COL b
tHZ
DIN b
DOUT n
DQ
tDS
DON’T CARE
Note:
Figure 16:
CL = 3. The READ command may be to any bank, and the WRITE command may be to any
bank.
READ-to-PRECHARGE
T0
T1
T2
T3
T4
T5
T6
T7
CLK
t RP
COMMAND
READ
NOP
NOP
NOP
NOP
PRECHARGE
NOP
ACTIVE
X = 1 cycle
ADDRESS
BANK
(a or all)
BANK a,
COL n
DOUT
n+1
DOUT
n
DQ
BANK a,
ROW
DOUT
n+2
DOUT
n+3
CL = 2
T0
T1
T2
T3
T4
T5
T6
T7
CLK
t RP
COMMAND
READ
NOP
NOP
NOP
PRECHARGE
NOP
NOP
ACTIVE
X = 2 cycles
ADDRESS
BANK a,
COL n
BANK
(a or all)
DOUT
n
DQ
DOUT
n+1
BANK a,
ROW
DOUT
n+2
DOUT
n+3
CL = 3
DON’T CARE
Note:
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256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
DQM is LOW.
28
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©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
Operations
Continuous page bursts can be truncated with the BURST TERMINATE command, and
fixed-length READ bursts may be truncated with a BURST TERMINATE command, provided that auto precharge was not activated. The BURST TERMINATE command should
be issued x cycles before the clock edge at which the last desired data element is valid,
where x = CL - 1. This is shown in Figure 17 for each possible CL; data element n + 3 is the
last desired data element of a longer burst.
Figure 17:
Terminating a READ Burst
T0
T1
T2
T3
T4
T5
T6
CLK
COMMAND
READ
ADDRESS
BANK,
COL n
NOP
NOP
NOP
BURST
TERMINATE
NOP
NOP
X = 1 cycle
DOUT
n+2
DOUT
n+1
DOUT
n
DQ
DOUT
n+3
CL = 2
T0
T1
T2
T3
T4
T5
T6
T7
CLK
COMMAND
READ
ADDRESS
BANK,
COL n
NOP
NOP
NOP
BURST
TERMINATE
NOP
NOP
NOP
X = 2 cycles
DOUT
n
DQ
DOUT
n+1
DOUT
n+2
DOUT
n+3
CL = 3
DON’T CARE
Note:
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256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
DQM is LOW.
29
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©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
Operations
WRITEs
WRITE bursts are initiated with a WRITE command, as shown in Figure 18 on page 30.
The starting column and bank addresses are provided with the WRITE command, and
auto precharge is either enabled or disabled for that access. If auto precharge is enabled,
the row being accessed is precharged at the completion of the burst. For the generic
WRITE commands used in the following illustrations, auto precharge is disabled.
During WRITE bursts, the first valid data-in element will be registered coincident with
the WRITE command. Subsequent data elements will be registered on each successive
positive clock edge. Upon completion of a fixed-length burst, assuming no other commands have been initiated, the DQs will remain High-Z and any additional input data
will be ignored (see Figure 19). A continuous page burst will proceed until terminated (at
the end of the page, it will wrap to the start address and continue).
Figure 18:
WRITE Command
CLK
CKE HIGH
CS#
RAS#
CAS#
WE#
A[8:0]
COLUMN
ADDRESS
A9, A11, A12
ENABLE AUTO PRECHARGE
A10
DISABLE AUTO PRECHARGE
BA[1:0]
BANK
ADDRESS
VALID ADDRESS
DON’T CARE
Data for any WRITE burst may be truncated with a subsequent WRITE command, and
data for a fixed-length WRITE burst may be immediately followed by data for a WRITE
command. The new WRITE command can be issued on any clock following the previous
WRITE command, and the data provided coincident with the new command applies to
the new command. An example is shown in Figure 20 on page 31. Data n + 1 is either the
last of a burst of two or the last desired of a longer burst. The 256Mb SDRAM uses a pipelined architecture. A WRITE command can be initiated on any clock cycle following a
previous WRITE command. Full-speed random write accesses within a page can be performed to the same bank, as shown in Figure 19 on page 31, or each subsequent WRITE
may be performed to a different bank.
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©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
Operations
Figure 19:
WRITE Burst
T0
T1
T2
T3
COMMAND
WRITE
NOP
NOP
NOP
ADDRESS
BANK,
COL n
CLK
DQ
DIN
n
DIN
n+1
DON’T CARE
Note:
Figure 20:
BL = 2. DQM is LOW.
WRITE-to-WRITE
T0
T1
T2
COMMAND
WRITE
NOP
WRITE
ADDRESS
BANK,
COL n
CLK
DQ
DIN
n
BANK,
COL b
DIN
n+1
DIN
b
DON’T CARE
Note:
BL = 2. DQM is LOW. Each WRITE command may be to any bank.
Data for any WRITE burst may be truncated with a subsequent READ command, and
data for a fixed-length WRITE burst may be immediately followed by a READ command.
Once the READ command is registered, the data inputs will be ignored, and WRITEs will
not be executed. An example is shown in Figure 21 on page 32. Data n + 1 is either the
last of a burst of two or the last desired of a longer burst.
Data for a fixed-length WRITE burst may be followed by, or truncated with, a PRECHARGE command to the same bank (provided that auto precharge was not activated),
and a continuous page WRITE burst can be truncated with a PRECHARGE command to
the same bank. The PRECHARGE command should be issued tWR after the clock edge at
which the last desired input data element is registered. The auto precharge mode
requires a tWR of at least one clock plus time (see note 24 on page 53), regardless of frequency.
In addition, when truncating a WRITE burst, the DQM signal must be used to mask
input data for the clock edge prior to, and the clock edge coincident with, the PRECHARGE command. An example is shown in Figure 21 on page 32. Data n + 1 is either
the last of a burst of two or the last desired of a longer burst. Following the PRECHARGE
command, a subsequent command to the same bank cannot be issued until tRP is met.
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©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
Operations
In the case of a fixed-length burst being executed to completion, a PRECHARGE command issued at the optimum time (as described above) provides the same operation
that would result from the same fixed-length burst with auto precharge. The disadvantage of the PRECHARGE command is that it requires that the command and address
buses be available at the appropriate time to issue the command; the advantage of the
PRECHARGE command is that it can be used to truncate fixed-length or continuous
page bursts.
Figure 21:
Random WRITE Cycles
T0
T1
T2
T3
COMMAND
WRITE
WRITE
WRITE
WRITE
ADDRESS
BANK,
COL n
BANK,
COL a
BANK,
COL x
BANK,
COL m
DIN
n
DIN
a
DIN
x
DIN
m
CLK
DQ
DON’T CARE
Note:
Figure 22:
Each WRITE command may be to any bank. DQM is LOW.
WRITE-to-READ
T0
T1
T2
T3
T4
T5
COMMAND
WRITE
NOP
READ
NOP
NOP
NOP
ADDRESS
BANK,
COL n
DOUT
b
DOUT
b+1
CLK
DQ
DIN
n
BANK,
COL b
DIN
n+1
DON’T CARE
Note:
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256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
BL = 2. The WRITE command may be to any bank, and the READ command may be to any
bank. DQM is LOW. CL = 2 for illustration.
32
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©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
Operations
Figure 23:
WRITE-to-PRECHARGE
T0
T1
T2
T3
T4
T5
T6
NOP
ACTIVE
NOP
CLK
tWR@ tCK ≥ 15ns
DQM
t RP
COMMAND
ADDRESS
WRITE
NOP
NOP
PRECHARGE
BANK
(a or all)
BANK a,
COL n
BANK a,
ROW
t WR
DQ
DIN
n
DIN
n+1
tWR@ tCK < 15ns
DQM
t RP
COMMAND
ADDRESS
WRITE
NOP
NOP
PRECHARGE
BANK
(a or all)
BANK a,
COL n
NOP
NOP
ACTIVE
BANK a,
ROW
t WR
DQ
DIN
n
DIN
n+1
DON’T CARE
Note:
Figure 24:
DQM could remain LOW in this example if the WRITE burst is a fixed length of two.
Terminating a WRITE Burst
T0
T1
T2
COMMAND
WRITE
BURST
TERMINATE
ADDRESS
BANK,
COL n
(Address)
DIN
n
(Data)
CLK
DQ
NEXT
COMMAND
DON’T CARE
Note:
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256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
DQMs are LOW.
33
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
Operations
Fixed-length or continuous page WRITE bursts can be truncated with the BURST TERMINATE command. When truncating a WRITE burst, the input data applied coincident
with the BURST TERMINATE command will be ignored. The last data written (provided
that DQM is LOW at that time) will be the input data applied one clock previous to the
BURST TERMINATE command. This is shown in Figure 22 on page 32, where data n is
the last desired data element of a longer burst.
PRECHARGE
The PRECHARGE command (see Figure 25) is used to deactivate the open row in a particular bank or the open row in all banks. The bank(s) will be available for a subsequent
row access some specified time (tRP) after the precharge command is issued. Input A10
determines whether one or all banks are to be precharged, and in the case where only
one bank is to be precharged, inputs BA[1:0] select the bank. When all banks are to be
precharged, inputs BA[1:0] are treated as “Don’t Care.” Once a bank has been precharged, it is in the idle state and must be activated prior to any READ or WRITE commands being issued to that bank.
Figure 25:
PRECHARGE Command
CLK
CKE
HIGH
CS#
RAS#
CAS#
WE#
A[9:0], A11, A12
All Banks
A10
Bank Selected
BA[1:0]
BANK
ADDRESS
VALID ADDRESS
DON’T CARE
Power-Down
Power-down occurs if CKE is registered LOW coincident with a NOP or COMMAND
INHIBIT when no accesses are in progress. If power-down occurs when all banks are
idle, this mode is referred to as precharge power-down; if power-down occurs when
there is a row active in any bank, this mode is referred to as active power-down. Entering
power-down deactivates the input and output buffers, excluding CKE, for maximum
power savings while in standby. The device may not remain in the power-down state
longer than the refresh period (64ms) since no REFRESH operations are performed in
this mode.
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34
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©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
Operations
The power-down state is exited by registering a NOP or COMMAND INHIBIT and CKE
HIGH at the desired clock edge (meeting tCKS). See Figure 24.
Figure 26:
Power-Down
((
))
((
))
CLK
tCKS
CKE
> tCKS
((
))
COMMAND
((
))
((
))
NOP
NOP
All banks idle
Input buffers gated off
Enter power-down mode
Exit power-down mode
ACTIVE
tRCD
tRAS
tRC
DON’T CARE
Deep Power-Down
Deep power-down mode is a maximum power savings feature achieved by shutting off
the power to the entire memory array of the device. Data in the memory array will not be
retained once deep power-down mode is executed. Deep power-down mode is entered
by having all banks idle then CS# and WE# held LOW with RAS# and CAS# HIGH at the
rising edge of the clock, while CKE is LOW. CKE must be held LOW during deep powerdown.
To exit deep power-down mode, CKE must be asserted HIGH. Upon exit of Deep PowerDown mode, at least 200µs of valid clocks with either NOP or COMMAND INHIBIT commands are applied to the command bus, followed by a full Mobile SDRAM initialization
sequence, is required.
Clock Suspend
The clock suspend mode occurs when a column access/burst is in progress and CKE is
registered LOW. In the clock suspend mode, the internal clock is deactivated, “freezing”
the synchronous logic.
For each positive clock edge on which CKE is sampled LOW, the next internal positive
clock edge is suspended. Any command or data present on the input balls at the time of
a suspended internal clock edge is ignored; any data present on the DQ balls remains
driven; and burst counters are not incremented, as long as the clock is suspended. (See
examples in Figure 27 and Figure 28 on page 37.)
Clock suspend mode is exited by registering CKE HIGH; the internal clock and related
operation will resume on the subsequent positive clock edge.
Burst Read/Single Write
The burst read/single write mode is entered by programming the write burst mode bit
(M9) in the mode register to a logic 1. In this mode, all WRITE commands result in the
access of a single column location (burst of one), regardless of the programmed BL.
READ commands access columns according to the programmed BL and sequence, just
as in the normal mode of operation (M9 = 0).
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35
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©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
Operations
Concurrent Auto Precharge
An access command (READ or WRITE) to a second bank while an access command with
auto precharge enabled on a first bank is executing is not allowed by SDRAM, unless the
SDRAM supports concurrent auto precharge. Micron SDRAM support concurrent auto
precharge. Four cases where concurrent auto precharge occurs are defined in the “READ
with Auto Precharge” and “WRITE with Auto Precharge” sections.
READ with Auto Precharge
1. Interrupted by a READ (with or without auto precharge): A READ to bank m will interrupt a READ on bank n, CL later. The precharge to bank n will begin when the READ
to bank m is registered (see Figure 29 on page 37).
2. Interrupted by a WRITE (with or without auto precharge): A WRITE to bank m will
interrupt a READ on bank n when registered. DQM should be used two clocks prior to
the WRITE command to prevent bus contention. The precharge to bank n will begin
when the WRITE to bank m is registered (see Figure 30 on page 38).
Figure 27:
Clock Suspend During WRITE Burst
T0
T1
NOP
WRITE
T2
T3
T4
T5
NOP
NOP
DIN
n+1
DIN
n+2
CLK
CKE
INTERNAL
CLOCK
COMMAND
ADDRESS
DIN
BANK,
COL n
DIN
n
DON’T CARE
Note:
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256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
For this example, BL = 4 or greater, and DM is LOW.
36
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©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
Operations
Figure 28:
Clock Suspend During READ Burst
T0
T1
T2
T3
T4
T5
T6
CLK
CKE
INTERNAL
CLOCK
COMMAND
READ
ADDRESS
BANK,
COL n
NOP
NOP
NOP
DOUT
n
DQ
NOP
NOP
DOUT
n+2
DOUT
n+1
DOUT
n+3
DON’T CARE
Note:
Figure 29:
For this example, CL = 2, BL = 4 or greater, and DQM is LOW.
READ with Auto Precharge Interrupted by a READ
T0
T1
T2
T3
T4
T5
T6
T7
CLK
COMMAND
BANK n
Internal
States
NOP
Page Active
READ - AP
BANK n
NOP
READ - AP
BANK m
READ with Burst of 4
NOP
NOP
NOP
Idle
Interrupt Burst, Precharge
tRP - BANK m
t RP - BANK n
BANK m
ADDRESS
Page Active
Precharge
READ with Burst of 4
BANK n,
COL a
NOP
BANK m,
COL d
DOUT
a
DQ
DOUT
a+1
DOUT
d
DOUT
d+1
CL = 3 (bank n)
CL = 3 (bank m)
DON’T CARE
Note:
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256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
DQM is LOW.
37
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©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
Operations
Figure 30:
READ with Auto Precharge Interrupted by a WRITE
T0
T1
T2
T3
T4
T5
T6
T7
CLK
COMMAND
BANK n
Internal
States
READ - AP
BANK n
Page
Active
NOP
NOP
NOP
READ with Burst of 4
WRITE - AP
BANK m
NOP
NOP
Interrupt Burst, Precharge
Idle
tRP - BANK n
Page Active
BANK m
ADDRESS
NOP
Write-Back
WRITE with Burst of 4
BANK n,
COL a
t WR - BANK m
BANK m,
COL d
1
DQM
DOUT
a
DQ
DIN
d
DIN
d+1
DIN
d+2
DIN
d+3
CL = 3 (bank n)
DON’T CARE
Note:
DQM is HIGH at T2 to prevent DOUT a +1 from contending with DIN d at T4.
WRITE with Auto Precharge
1. Interrupted by a READ (with or without auto precharge): A READ to bank m will interrupt a WRITE on bank n when registered, with the data-out appearing CL later. The
precharge to bank n will begin after tWR is met, where tWR begins when the READ to
bank m is registered. The last valid WRITE to bank n will be data-in registered one
clock prior to the READ to bank m (see Figure 31 on page 39).
2. Interrupted by a WRITE (with or without auto precharge): A WRITE to bank m will
interrupt a WRITE on bank n when registered. The precharge to bank n will begin
after tWR is met, where tWR begins when the WRITE to bank m is registered. The last
valid data WRITE to bank n will be data registered one clock prior to a WRITE to bank
m (see Figure 32 on page 39).
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©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
Operations
Figure 31:
WRITE with Auto Precharge Interrupted by a READ
T0
T1
T2
T3
T4
T5
T6
T7
CLK
COMMAND
BANK n
Internal
States
NOP
WRITE - AP
BANK n
Page Active
NOP
WRITE with Burst of 4
Page Active
BANK m
DIN
a
DQ
NOP
NOP
NOP
Interrupt Burst, Write-Back
Precharge
tWR - BANK n
tRP - BANK n
NOP
tRP - BANK m
READ with Burst of 4
BANK n,
COL a
ADDRESS
READ - AP
BANK m
BANK m,
COL d
DOUT
d+1
DOUT
d
DIN
a+1
CL = 3 (bank m)
DON’T CARE
Note:
Figure 32:
DQM is LOW.
WRITE with Auto Precharge Interrupted by a WRITE
T0
T1
T2
T3
T4
T5
T6
T7
CLK
COMMAND
BANK n
Internal
States
NOP
WRITE - AP
BANK n
Page Active
NOP
NOP
WRITE with Burst of 4
WRITE - AP
BANK m
NOP
Interrupt Burst, Write-Back
tWR - BANK n
BANK m
ADDRESS
DQ
Page Active
NOP
Precharge
tRP - BANK n
t WR - BANK m
Write-Back
WRITE with Burst of 4
BANK n,
COL a
DIN
a
NOP
BANK m,
COL d
DIN
a+1
DIN
a+2
DIN
d
DIN
d+1
DIN
d+2
DIN
d+3
DON’T CARE
Note:
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256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
DQM is LOW.
39
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256Mb: x16, x32 Mobile SDRAM
Truth Tables
Truth Tables
Table 6:
Truth Table – CKE
Notes: 1–4
CKEn-1
CKEn
Current State
Commandn
Actionn
L
L
L
H
H
L
Power-down
Self refresh
Clock suspend
Deep power-down
Power-down
Deep power-down
Self refresh
Clock suspend
All banks idle
All banks idle
All banks idle
Reading or writing
X
X
X
X
COMMAND INHIBIT or NOP
X
COMMAND INHIBIT or NOP
X
COMMAND INHIBIT or NOP
BURST TERMINATE
AUTO REFRESH
VALID
See Table 8 on page 43
Maintain power-down
Maintain self refresh
Maintain clock suspend
Maintain deep power-down
Exit power-down
Exit deep power-down
Exit self refresh
Exit clock suspend
Power-down entry
Deep power-down entry
Self refresh entry
Clock suspend entry
H
H
Notes
8
5
8
6
7
8
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 SDRAM immediately prior to clock edge n.
3. COMMANDn is the command registered at clock edge n, and ACTIONn is a result of COMMANDn.
4. All states and sequences not shown are illegal or reserved.
5. Exiting power-down at clock edge n will put the device in the all banks idle state in time
for clock edge n + 1 (provided that tCKS is met).
6. Exiting self refresh at clock edge n will put the device in the all banks idle state once tXSR
is met. COMMAND INHIBIT or NOP commands should be issued on any clock edges occurring during the tXSR period. A minimum of two NOP commands must be provided during
tXSR period.
7. After exiting clock suspend at clock edge n, the device will resume operation and recognize the next command at clock edge n + 1.
8. Deep power-down is power savings feature of this Mobile SDRAM device. This command is
BURST TERMINATE when CKE is HIGH and deep power-down when CKE is LOW.
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256Mb: x16, x32 Mobile SDRAM
Truth Tables
Table 7:
Truth Table – Current State Bank n, Command to Bank n
Notes: 1–6; notes appear below table
Current State
CS#
Any
H
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
Idle
Row active
Read
(auto precharge
disabled)
Write
(auto precharge
disabled)
RAS# CAS#
X
H
L
L
L
L
H
H
L
H
H
L
H
H
H
L
H
WE# Command (Action)
X
H
H
L
L
H
L
L
H
L
L
H
H
L
L
H
H
X
H
H
H
L
L
H
L
L
H
L
L
L
H
L
L
L
COMMAND INHIBIT (NOP/Continue previous operation)
NO OPERATION (NOP/Continue previous operation)
ACTIVE (Select and activate row)
AUTO REFRESH
LMR
PRECHARGE
READ (Select column and start READ burst)
WRITE (Select column and start WRITE burst)
PRECHARGE (Deactivate row in bank or banks)
READ (Select column and start new READ burst)
WRITE (Select column and start WRITE burst)
PRECHARGE (Truncate READ burst, start PRECHARGE)
BURST TERMINATE
READ (Select column and start READ burst)
WRITE (Select column and start new WRITE burst)
PRECHARGE (Truncate WRITE burst, start PRECHARGE)
BURST TERMINATE
Notes
7
7
11
10
10
8
10
10
8
9
10
10
8
9
Notes: 1. This table applies when CKEn-1 was HIGH and CKEn is HIGH (see Table 6 on page 40) and
after tXSR has been met (if the previous state was self refresh).
2. This table is bank-specific, except where noted; i.e., the current state is for a specific bank
and the commands shown are those allowed to be issued to that bank when in that state.
Exceptions are covered in the notes below.
3. Current state definitions:
Idle:
Row active:
Read:
Write:
The bank has been precharged, and tRP has been met.
A row in the bank has been activated, and tRCD has been met. No data
bursts/accesses and no register accesses are in progress.
A READ burst has been initiated, with auto precharge disabled, and has
not yet terminated or been terminated.
A WRITE burst has been initiated, with auto precharge disabled, and has
not yet terminated or been terminated.
4. The following states must not be interrupted by a command issued to the same bank.
COMMAND INHIBIT or NOP commands, or allowable commands to the other bank should
be issued on any clock edge occurring during these states. Allowable commands to the
other bank are determined by its current state and Table 7, and according to Table 8 on
page 43.
Precharging:
Starts with registration of a PRECHARGE command and ends when
is met. Once tRP is met, the bank will be in the idle state.
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.
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.
Starts with registration of a WRITE command with auto precharge
enabled and ends whentRP has been met. Once tRP is met, the bank
will be in the idle state.
tRP
Row activating:
Read w/autoprecharge enabled:
Write w/autoprecharge enabled:
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Truth Tables
5. The following states must not be interrupted by any executable command; DESELECT or
NOP commands must be applied on each positive clock edge during these states.
Refreshing:
Accessing mode
register:
Precharging all:
Starts with registration of an AUTO REFRESH command and ends
when tRFC is met. Once tRFC is met, the Mobile SDRAM will be in the
all banks idle state.
Starts with registration of an LMR command and ends when tMRD
has been met. Once tMRD is met, the Mobile SDRAM will be in the
all banks idle state.
Starts with registration of a PRECHARGE ALL command and ends
when tRP is met. Once tRP is met, all banks will be in the idle state.
6. All states and sequences not shown are illegal or reserved
7. Not bank-specific; requires that all banks are idle.
8. May or may not be bank-specific; if all banks are to be precharged, all must be in a valid
state for precharging.
9. Not bank-specific; BURST TERMINATE affects the most recent READ or WRITE 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. Does not affect the state of the bank and acts as a NOP to that bank.
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Truth Tables
Table 8:
Truth Table – Current State Bank n, Command to Bank m
Notes: 1–6; notes appear below and on next page
Current State
CS#
Any
H
L
X
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
Idle
Row activating,
active, or
precharging
Read
(auto precharge
disabled)
Write
(auto precharge
disabled)
Read
(with auto
precharge)
Write
(with auto
precharge)
RAS# CAS# WE# Command (Action)
X
H
X
L
H
H
L
L
H
H
L
L
H
H
L
L
H
H
L
L
H
H
L
X
H
X
H
L
L
H
H
L
L
H
H
L
L
H
H
L
L
H
H
L
L
H
X
H
X
H
H
L
L
H
H
L
L
H
H
L
L
H
H
L
L
H
H
L
L
Notes
COMMAND INHIBIT (NOP/Continue previous operation)
NO OPERATION (NOP/Continue previous operation)
Any command otherwise allowed to bank m
ACTIVE (Select and activate row)
READ (Select column and start READ burst)
WRITE (Select column and start WRITE burst)
PRECHARGE
ACTIVE (Select and activate row)
READ (Select column and start new READ burst)
WRITE (Select column and start WRITE burst)
PRECHARGE
ACTIVE (Select and activate row)
READ (Select column and start READ burst)
WRITE (Select column and start new WRITE burst)
PRECHARGE
ACTIVE (Select and activate row)
READ (Select column and start new READ burst)
WRITE (Select column and start WRITE burst)
PRECHARGE
ACTIVE (Select and activate row)
READ (Select column and start READ burst)
WRITE (Select column and start new WRITE burst)
PRECHARGE
7
7
7, 8
7, 9
10
7, 11
7, 12
10
7, 13, 14
7, 13, 15
10
7, 13, 16
7, 13, 17
10
Notes: 1. This table applies when CKEn-1 was HIGH and CKEn is HIGH (see Table 6 on page 40) and
after tXSR has been met (if the previous state was self refresh).
2. This table describes alternate bank operation, except where noted; i.e., the current state is
for bank n and the commands shown are those allowed to be issued to bank m (assuming
that bank m is in such a state that the given command is allowable). Exceptions are covered in the notes below.
3. Current state definitions:
Idle:
Row active:
Read:
Write:
Read w/autoprecharge enabled:
Write w/autoprecharge enabled:
The bank has been precharged, and tRP has been met.
A row in the bank has been activated, and tRCD has been met. No
data bursts/accesses and no register accesses are in progress.
A READ burst has been initiated, with auto precharge disabled, and
has not yet terminated or been terminated.
A WRITE burst has been initiated, with auto precharge disabled, and
has not yet terminated or been terminated.
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.
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.
4. AUTO REFRESH, SELF 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.
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Truth Tables
6. All states and sequences not shown are illegal or reserved.
7. READs or WRITEs to bank m listed in the Command (Action) column include READs or
WRITEs with auto precharge enabled and READs or WRITEs with auto precharge disabled.
8. For a READ without auto precharge interrupted by a READ (with or without auto precharge), the READ to bank m will interrupt the READ on bank n, CL later (see Figure 11 on
page 24).
9. For a READ without auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank m will interrupt the READ on bank n when registered (see
Figure 12 on page 25 and Figure 13 on page 26). DQM should be used one clock prior to
the WRITE command to prevent bus contention.
10. Burst in bank n continues as initiated.
11. For a WRITE without auto precharge interrupted by a READ (with or without auto precharge), the READ to bank m will interrupt the WRITE on bank n when registered (see
Figure 20 on page 31), with the data-out appearing CL later. The last valid WRITE to bank
n will be data-in registered one clock prior to the READ to bank m.
12. For a WRITE without auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank will interrupt the WRITE on bank n when registered (see
Figure 18 on page 30). The last valid WRITE to bank n will be data-in registered one clock
prior to the READ to bank m.
13. Concurrent auto precharge: Bank n will initiate the auto precharge command when its
burst has been interrupted by bank m burst.
14. For a READ with auto precharge interrupted by a READ (with or without auto precharge),
the READ to bank m will interrupt the READ on bank n, CL later. The PRECHARGE to bank
n will begin when the READ to bank m is registered.
15. For a READ with auto precharge interrupted by a WRITE (with or without auto precharge),
the WRITE to bank m will interrupt the READ on bank n when registered. DQM should be
used two clocks prior to the WRITE command to prevent bus contention. The PRECHARGE
to bank n will begin when the WRITE to bank m is registered.
16. For a WRITE with auto precharge interrupted by a READ (with or without auto precharge),
the READ to bank m will interrupt the WRITE on bank n when registered, with the dataout appearing CL later. The PRECHARGE to bank n will begin after tWR is met, where tWR
begins when the READ to bank m is registered. The last valid WRITE bank n will be data-in
registered one clock prior to the READ to bank m.
17. For a WRITE with auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank m interrupt the WRITE on bank n when registered. The PRECHARGE to bank n will begin after tWR is met, where tWR begins when the WRITE to bank
m is registered. The last valid WRITE to bank n will be data registered one clock to the
WRITE to bank m.
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Electrical Specifications
Electrical Specifications
Absolute Maximum Ratings
Stresses greater than those listed in Table 9 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 9:
Absolute Maximum Ratings
Voltage/Temperature
Min
Max
Units
Voltage on VDD/VDDQ supply relative to VSS (1.8V)
Voltage on inputs, NC or I/O balls relative to VSS (1.8V)
Storage temperature plastic
–0.3
–0.3
–55
+2.7
+2.7
+150
V
Table 10:
DC Electrical Characteristics and Operating Conditions
Notes: 1, 5, 6; notes appear on page 52 and 53; VDD/VDDQ = 1.7–1.95V
Parameter/Condition
Supply voltage
I/O supply voltage
Input high voltage: Logic 1; All inputs
Input low voltage: Logic 0; All inputs
Output high voltage: All inputs: IOUT = –4mA
Output low voltage: All inputs: IOUT = 4mA
Input leakage current:
Any input 0V ≤ VIN ≤ VDD (All other balls not under test = 0V)
Output leakage current: DQ are disabled; 0V ≤ VOUT ≤ VDDQ
Operating temperature
TA (commercial)
TA (industrial)
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Symbol
Min
Max
Units
VDD
VDDQ
VIH
VIL
VOH
VOL
II
1.7
1.7
0.8 × VDDQ
–0.3
0.9 × VDDQ
–
–1.0
1.95
1.95
VDDQ + 0.3
+0.3
–
0.2
1.0
V
V
V
V
V
V
µA
IOZ
-1.5
1.5
µA
+70
+85
°C
Notes
22
22
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Electrical Specifications
Table 11:
Electrical Characteristics and Recommended AC Operating Conditions
Notes: 5, 6, 8, 9, 11; notes appear on page 52 and 53
AC Characteristics
-75
Parameter
Access time from CLK (pos. edge)
Address hold time
Address setup time
CLK high-level width
CLK low-level width
Clock cycle time
CKE hold time
CKE setup time
CS#, RAS#, CAS#, WE#, DQM hold time
CS#, RAS#, CAS#, WE#, DQM setup time
Data-in hold time
Data-in setup time
Data-out High-Z time
Data-out Low-Z time
Data-out hold time (load)
Data-out hold time (no load)
ACTIVE-to-PRECHARGE command
ACTIVE-to-ACTIVE command period
ACTIVE-to-READ or WRITE delay
Refresh period (8192 rows)
AUTO REFRESH period
PRECHARGE command period
ACTIVE bank a to ACTIVE bank b command
Transition time
WRITE recovery time
Exit SELF REFRESH to ACTIVE command
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Symbol
CL = 3
CL = 2
CL = 3
CL = 2
CL = 3
CL = 2
Min
t
AC (3)
AC (2)
t
AH
t
AS
t
CH
t
CL
tCK (3)
tCK (2)
t
CKH
tCKS
tCMH
tCMS
tDH
tDS
tHZ (3)
tHZ (2)
tLZ
tOH
t
OHN
tRAS
tRC
tRCD
tREF
tRFC
tRP
tRRD
tT
tWR
t
XSR
Max
Min
6
8
t
46
-8
1
1.5
3
3
7.5
9.6
1
2.5
1
1.5
1
1.5
7
9
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ms
ns
ns
tCK
ns
ns
ns
120,000
7
9
1
2.5
1.8
48
72
20
64
80
19
2
0.3
15
80
Units
1
2.5
3
3
8
10
1
2.5
1
2.5
1
2.5
6
9
1
2.5
1.8
44
67.5
19
Max
1.2
120,000
64
80
19
2
0.5
15
80
1.2
Notes
9
23
23
10
10
25
7
31
20
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Electrical Specifications
Table 12:
AC Functional Characteristics
Notes: 5, 6, 8, 9,11 notes appear on page 52 and 53
Parameter
Symbol
t
READ/WRITE command to READ/WRITE command
CKE to clock disable or power-down entry mode
CKE to clock enable or power-down exit setup mode
DQM to input data delay
DQM to data mask during WRITEs
DQM to data High-Z during READs
WRITE command to input data delay
Data-in to ACTIVE command
Data-in to PRECHARGE command
Last data-in to burst STOP command
Last data-in to new READ/WRITE command
Last data-in to PRECHARGE command
LMR command to ACTIVE or REFRESH command
Data-out High-Z from PRECHARGE command
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CCD
CKED
t
PED
t
DQD
tDQM
t
DQZ
t
DWD
t
DAL
t
DPL
t
BDL
t
CDL
tRDL
tMRD
tROH(3)
tROH(2)
t
CL = 3
CL = 2
47
-75
1
1
1
0
0
2
0
5
2
1
1
2
2
3
2
-8
1
1
1
0
0
2
0
5
2
1
1
2
2
3
2
Units
t
CK
CK
t
CK
t
CK
tCK
t
CK
t
CK
t
CK
t
CK
t
CK
t
CK
tCK
tCK
tCK
tCK
t
Notes
17
14
14
17
17
17
17
15, 21
16, 21
17
17
16, 21
25
17
17
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Electrical Specifications
Table 13:
IDD Specifications and Conditions (x16)
Notes: 1, 5, 6, 11, 13; notes appear on page 52 and 53; VDD/VDDQ = 1.7–1.95V
Max
Parameter/Condition
Operating current:
Active mode; BL = 1; READ or WRITE; tRC = tRC (MIN)
Standby current:
Power-down mode; All banks idle; CKE = LOW
Precharge nonpower-down standby current with clock stopped: All
banks idle; CKE is LOW, CS is HIGH; CK = LOW, CK# = HIGH; Address and
control inputs are switching; Data bus inputs are stable
Standby current:
Non-power-down mode; All banks idle; CKE = HIGH
Precharge nonpower-down standby current with clock stopped: All
banks idle; CKE is LOW, CS is HIGH; CK = LOW, CK# = HIGH; Address and
control inputs are switching; Data bus inputs are stable
Standby current:
Active mode; CKE = LOW; CS# = HIGH; All banks active; No accesses in
progress
Precharge nonpower-down standby current with clock stopped: All
banks idle; CKE is LOW, CS is HIGH; CK = LOW, CK# = HIGH; Address and
control inputs are switching; Data bus inputs are stable
Standby current:
Active mode; CKE = HIGH; CS# = HIGH; All banks active after tRCD met;
No accesses in progress
Precharge nonpower-down standby current with clock stopped: All
banks idle; CKE is LOW, CS is HIGH; CK = LOW, CK# = HIGH; Address and
control inputs are switching; Data bus inputs are stable
Operating current:
Burst mode; READ or WRITE; All banks active, half DQs toggling every
cycle
tRFC = tRFC (MIN)
Auto refresh current:
tRFC = 7.8125µs
CKE = HIGH; CS# = HIGH
Deep power-down
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Symbol
-75
-8
Units
Notes
IDD1
65
60
mA
IDD2P
standard
IDD2P
low-power
IDD2PS
standard
IDD2PS
low-power
IDD2N
300
300
µA
220
220
µA
300
300
µA
1, 18,
19
1, 18,
19
1, 18,
19
30
220
220
µA
30
20
20
mA
IDD2NS
5
5
mA
IDD3P
5
5
mA
IDD3PS
3
3
mA
IDD3N
25
25
mA
IDD3NS
10
10
mA
IDD4
90
85
mA
1, 18,
19
IDD5
IDD6
100
5
95
5
mA
mA
IZZ
10
10
µA
1, 12,
18 19,
26
29, 30
1, 12,
19
1, 12,
19
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Electrical Specifications
Table 14:
IDD Specifications and Conditions (x32)
Notes: 1, 5, 6, 11, 13; notes appear on page 52 and 53; VDD/VDDQ = 1.7–1.95V
Max
Parameter/Condition
Operating current:
Active mode; BL = 1; READ or WRITE; tRC = tRC (MIN)
Standby current:
Power-down mode; All banks idle; CKE = LOW
Precharge nonpower-down standby current with clock stopped: All
banks idle; CKE is LOW, CS is HIGH; CK = LOW, CK# = HIGH; Address and
control inputs are switching; Data bus inputs are stable
Standby current:
Non-power-down mode; All banks idle; CKE = HIGH
Precharge nonpower-down standby current with clock stopped: All
banks idle; CKE is LOW, CS is HIGH; CK = LOW, CK# = HIGH; Address and
control inputs are switching; Data bus inputs are stable
Standby current:
Active mode; CKE = LOW; CS# = HIGH; All banks active; No accesses in
progress
Precharge nonpower-down standby current with clock stopped: All
banks idle; CKE is LOW, CS is HIGH; CK = LOW, CK# = HIGH; Address and
control inputs are switching; Data bus inputs are stable
Standby current:
Active mode; CKE = HIGH; CS# = HIGH; All banks active after tRCD met;
No accesses in progress
Precharge nonpower-down standby current with clock stopped: All
banks idle; CKE is LOW, CS is HIGH; CK = LOW, CK# = HIGH; Address and
control inputs are switching; Data bus inputs are stable
Operating current:
Burst mode; READ or WRITE; All banks active, half DQs toggling every
cycle
tRFC = tRFC (MIN)
Auto refresh current:
CKE = HIGH; CS# = HIGH
tRFC = 7.8125µs
Deep power-down
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Symbol
-75
-8
Units
Notes
IDD1
95
90
mA
IDD2P
standard
IDD2P
lowpower
IDD2PS
standard
IDD2PS
lowpower
IDD2N
300
300
µA
1, 18,
19
30
220
220
µA
30
300
300
µA
30
220
220
µA
30
20
20
mA
IDD2NS
5
5
mA
IDD3P
5
5
mA
IDD3PS
3
3
mA
IDD3N
25
25
mA
IDD3NS
10
10
mA
IDD4
120
115
mA
1, 18,
19
IDD5
100
95
mA
IDD6
IZZ
5
10
5
10
mA
µA
1, 12,
18, 26
19, 27
29, 30
1, 12,
19
1, 12,
19
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Electrical Specifications
Table 15:
IDD7 – Self Refresh Current Options
Notes: 2, 28, 30; notes appear on page 52 and page 53
Temperature-Compensated Self Refresh
Parameter/Condition
Self refresh current:
CKE = LOW – 4-bank refresh
Self refresh current:
CKE = LOW – 2-bank refresh
Self refresh current:
CKE = LOW – 1-bank refresh
Self refresh current:
CKE = LOW – Half-bank refresh
Self refresh current:
CKE = LOW – Quarter-bank refresh
Figure 33:
Maximum
Temperature
Low IDD7
Option “L”
Standard IDD7
Units
85ºC
70ºC
45ºC
15ºC
85ºC
70ºC
45ºC
15ºC
85ºC
70ºC
45ºC
15ºC
85ºC
70ºC
45ºC
15ºC
85ºC
70ºC
45ºC
15ºC
220
175
140
125
200
150
130
115
185
140
120
115
175
125
115
110
170
120
110
105
300
210
190
180
275
180
160
150
265
160
140
140
255
150
130
125
250
140
120
115
µA
µA
µA
µA
µA
µA
µA
µA
µA
µA
µA
µA
µA
µA
µA
µA
µA
µA
µA
µA
Typical Self Refresh Current vs. Temperature
150
Full Array
1/2 Array
125
1/4 Array
Temperature (°C)
Current (µA)
1/8 Array
100
1/16 Array
75
50
25
0
-40
-30
-20
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-10
0
10
20
50
30
40
50
60
70
80
90
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Electrical Specifications
Table 16:
Capacitance
Note: 2; notes appear on page 52 and 53
Parameter
Input capacitance: CLK
Input capacitance: All other input-only balls
Input/output capacitance: DQs
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Symbol
Min
Max
Units
CI1
CI2
CIO
1.5
2.0
2.0
4.5
4.5
6.0
pF
pF
pF
51
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256Mb: x16, x32 Mobile SDRAM
Notes
Notes
1. All voltages referenced to VSS.
2. This parameter is sampled. VDD, VDDQ = +1.8V; TA = 25°C; ball under test biased at
0.9V; f = 1 MHz.
3. IDD is dependent on output loading and cycle rates. Specified values are obtained
with minimum cycle time and the outputs open.
4. Enables on-chip refresh and address counters.
5. The minimum specifications are used only to indicate cycle time at which proper
operation over the full temperature range (–40°C ≤ TA ≤ +85°C for TA on IT parts) is
ensured.
6. An initial pause of 100µs is required after power-up, followed by two AUTO REFRESH
commands, before proper device operation is ensured. (VDD and VDDQ must be powered up simultaneously. VSS and VSSQ must be at same potential.) The two AUTO
REFRESH command wake-ups should be repeated any time the tREF refresh requirement is exceeded.
7. AC characteristics assume tT = 1ns.
8. In addition to meeting the transition rate specification, the clock and CKE must transit between VIH and VIL (or between VIL and VIH) in a monotonic manner.
9. Outputs measured for 1.8V at 0.9V with equivalent load:
Q
20pF
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
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256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
Test loads with full DQ driver strength. Performance will vary with actual system DQ
bus capacitive loading, termination, and programmed drive strength.
tHZ defines the time at which the output achieves the open circuit condition; it is not
a reference to VOH or VOL. The last valid data element will meet tOH before going
High-Z.
AC timing and IDD tests have VIL and VIH, with timing referenced to VIH/2 = crossover
point. If the input transition time is longer than tT (MAX), then the timing is referenced at VIL,max and VIH,min and no longer at the VIH/2 crossover point.
Other input signals are allowed to transition no more than once every two clocks and
are otherwise at valid VIH or VIL levels.
IDD specifications are tested after the device is properly initialized.
Timing actually specified by tCKS; clock(s) specified as a reference only at minimum
cycle rate.
Timing actually specified by tWR plus tRP; clock(s) specified as a reference only at
minimum cycle rate.
Timing actually specified by tWR.
Required clocks are specified by JEDEC functionality and are not dependent on any
timing parameter.
The IDD current will increase or decrease proportionally according to the amount of
frequency alteration for the test condition.
Address transitions average one transition every two clocks.
CLK must be toggled a minimum of two times during this period.
Based on tCK = 7.5ns for -75,tCK = 8ns for -8, at CL = 3.
52
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Notes
22. VIH overshoot: VIH,max = VDDQ + 2V for a pulse width ≤ 3ns, and the pulse width cannot be greater than one third of the cycle rate. VIL undershoot: VIL,min = –2V for a pulse
width ≤ 3ns.
23. The clock frequency can only be changed during clock stop, power-down, or while in
a self-refresh mode.
24. Auto precharge mode only. The precharge timing budget (tRP) begins at 7ns for -8
after the first clock delay, after the last WRITE is executed. May not exceed limit set for
precharge mode.The clock frequency can only be changed during
25. Parameter guaranteed by design.
26. CKE is HIGH during refresh command period tRFC (MIN), else CKE is LOW.
27. The IDD6 limit is actually a nominal value and does not result in a fail value.
28. Values for IDD7 for 70°C, 45°C, 15°C, and IDD7 1/2-bank and 1/4-bank are sampled
only. Values for IDD7 4-bank, 2-bank, and 1-bank for 85°C are 100% tested.
29. Deep power-down current is a nominal value at 25°C. This parameter is not tested.
30. Test conditions include 500ms delay prior to measurement.
31. Auto precharge mode only. The precharge timing budget (tRP) begins at 7.5ns for -75
and 7ns for -8 after the first clock delay, after the last WRITE is executed. For auto precharge mode, at least one clock cycle is required during tWR.
PDF:09005aef8219eeeb/Source: 09005aef8219eedd
256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
53
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256Mb: x16, x32 Mobile SDRAM
Timing Diagrams
Timing Diagrams
Figure 34:
Initialize and Load Mode Register
T0
CLK
((
))
((
))
Tn + 1
T1
tCK
To + 1
Tp + 1
Tq + 1
Tr + 1
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
tCKS tCKH
CKE
((
))
((
))
COMMAND1
((
))
((
))
DQM
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
ADDR
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
CODE
((
))
((
))
CODE
((
))
((
))
VALID
((
))
((
))
A10
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
CODE
((
))
((
))
CODE
((
))
((
))
VALID
((
))
((
))
BA[1:0]
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
BA0
BA0 == L,
L,
BA1
BA1==HL
((
))
((
))
VALID
((
))
((
))
DQ
((
))
((
))
((
))
((
))
tRP
tRFC2
tCMS tCMH
NOP
((
))
((
))
PRE
AR
((
))
((
))
AR
((
))
((
))
LMR
((
))
((
))
LMR
((
))
((
))
((
))
((
))
VALID
((
))
((
))
((
))
((
))
((
))
((
))
tAS tAH
ALL BANKS
t AS tAH
tAS tAH
High-Z
BA0 = L,
BA1 = L
((
))
((
))
((
))
T = 100µs
Power-up:
VDD and
CLK stable
tRFC2
tMRD3
Load Mode
Register
Precharge
all banks
tMRD3
Load Extended
Mode Register
DON’T CARE
Notes: 1. PRE = PRECHARGE command; AR = AUTO REFRESH command; LMR = LOAD MODE REGISTER command.
2. Only NOPs or COMMAND INHIBITs may be issued during tRFC time.
3. At least one NOP or COMMAND INHIBIT is required during tMRD time.
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256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
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©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
Timing Diagrams
Figure 35:
Power-Down Mode
T0
T1
tCK
CLK
T2
((
))
((
))
tCL
tCKS
tCH
CKE
tCKS
Tn + 1
Tn + 2
tCKS
((
))
tCKH
tCMS tCMH
COMMAND
PRECHARGE
NOP
((
))
((
))
NOP
NOP
ACTIVE
DQM
((
))
((
))
ADDR
((
))
((
))
ROW
((
))
((
))
ROW
((
))
((
))
BANK
ALL BANKS
A10
SINGLE BANK
tAS
BA[1:0]
tAH
BANK(S)
High-Z
((
))
DQ
Two clock cycles
Input buffers gated off while in
power-down mode
Precharge all
active banks
All banks idle
All banks idle, enter
power-down mode
Exit power-down mode
DON’T CARE
Notes: 1. Violating refresh requirements during power-down may result in a loss of data.
See Table 11 on page 46.
PDF:09005aef8219eeeb/Source: 09005aef8219eedd
256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
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©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
Timing Diagrams
Figure 36:
Clock Suspend Mode
T0
T1
tCK
CLK
T2
T3
T4
T5
T6
T7
T8
T9
tCL
tCH
tCKS tCKH
CKE
tCKS
tCKH
tCMS tCMH
COMMAND
READ
NOP
NOP
NOP
NOP
NOP
WRITE
NOP
tCMS tCMH
DQM
tAS
ADDR
tAH
COLUMN m2
tAS
COLUMN e
tAH
A10
tAS
BA[1:0]
tAH
BANK
BANK
tAC
tOH
tAC
DQ
DOUT m
tHZ
DOUT m + 1
tDS
tDH
DOUT e
DOUT e + 1
tLZ
DON’T CARE
UNDEFINED
Notes: 1. For this example, BL = 2, CL = 3, and auto precharge is disabled.
PDF:09005aef8219eeeb/Source: 09005aef8219eedd
256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
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©2006 Micron Technology, Inc. All rights reserved.
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Timing Diagrams
Figure 37:
Auto Refresh Mode
T0
CLK
T1
tCK
T2
((
))
((
))
tCH
tCKS
tCKH
tCMS
tCMH
PRECHARGE
NOP
((
))
( ( NOP
))
AUTO
REFRESH
NOP
AUTO
REFRESH
NOP
((
))
( ( NOP
))
ACTIVE
((
))
((
))
((
))
((
))
((
))
((
))
ROW
((
))
((
))
((
))
((
))
ROW
((
))
((
))
((
))
((
))
BANK
((
))
((
))
ADDR
ALL BANKS
A10
SINGLE BANK
tAS
To + 1
((
))
((
))
((
))
DQM
BA[1:0]
((
))
((
))
((
))
CKE
COMMAND
Tn + 1
tCL
tAH
BANK(S)
DQ High-Z
tRP
tRFC
tRFC
Precharge all
active banks
DON’T CARE
UNDEFINED
Notes: 1. Each AUTO REFRESH command performs a REFRESH cycle. Back-to-back commands are not
required.
See Table 11 on page 46.
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256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
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©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
Timing Diagrams
Figure 38:
Self Refresh Mode
T0
CLK
T1
tCK
tCL
tCH
T2
tCKS
> tRAS
CKE
COMMAND
tCKS
tCKH
tCMS
tCMH
PRECHARGE
Tn + 1
((
))
((
))
AUTO
REFRESH
((
))
((
))
((
))
NOP ( (
((
))
((
))
((
))
((
))
ADDR
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
ALL BANKS
SINGLE BANK
tAS
BA[1:0]
DQ
To + 2
AUTO
REFRESH
))
DQM
A10
To + 1
((
))
((
))
((
))
NOP
((
))
((
))
tAH
BANK(S)
High-Z
((
))
((
))
tRP
Precharge all
active banks
tXSR
Enter self refresh mode
Exit self refresh mode
(Restart refresh time base)
CLK stable prior to exiting
self refresh mode
PDF:09005aef8219eeeb/Source: 09005aef8219eedd
256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
58
DON’T CARE
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2006 Micron Technology, Inc. All rights reserved.
256Mb: x16, x32 Mobile SDRAM
Timing Diagrams
Figure 39:
READ – without Auto Precharge
T0
T1
tCK
CLK
T2
T3
T4
T5
NOP
NOP
T6
T7
T8
NOP
ACTIVE
tCL
tCH
tCKS
tCKH
tCMS
tCMH
CKE
COMMAND
ACTIVE
NOP
READ
tCMS
NOP
PRECHARGE
tCMH
DQM
tAS
ADDR
tAS
ROW
COLUMN m
tAH
ALL BANKS
ROW
A10
tAS
BA[1:0]
tAH
ROW
ROW
SINGLE BANK
DISABLE AUTO PRECHARGE
tAH
BANK
BANK
BANK(S)
tAC
tOH
tAC
DQ
DOUT m
tAC
tOH
DOUT m + 1
BANK
tAC
tOH
tOH
DOUT m + 2
DOUT m + 3
tLZ
tRCD
tRP
CL
tHZ
tRAS
tRC
DON’T CARE
UNDEFINED
Notes: 1. For this example, BL = 4, CL = 2, and the READ burst is followed by a manual PRECHARGE.
PDF:09005aef8219eeeb/Source: 09005aef8219eedd
256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
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Timing Diagrams
Figure 40:
READ – with Auto Precharge
T0
T1
tCK
CLK
T2
T3
T4
T5
NOP
NOP
T6
T7
T8
NOP
NOP
ACTIVE
tCL
tCH
tCKS
tCKH
tCMS
tCMH
CKE
COMMAND
ACTIVE
NOP
READ
tCMS
NOP
tCMH
DQM
tAS
ROW
ADDR
tAS
ROW
COLUMN m
tAH
ENABLE AUTO PRECHARGE
ROW
A10
tAS
BA[1:0]
tAH
ROW
tAH
BANK
BANK
BANK
tAC
tOH
tAC
DQ
DOUT m
tAC
tOH
DOUT m + 1
tAC
tOH
tOH
DOUT m + 2
DOUT m + 3
tLZ
tRCD
tRP
CL
tHZ
tRAS
tRC
DON’T CARE
UNDEFINED
Notes: 1. For this example, BL = 4, CL = 2.
PDF:09005aef8219eeeb/Source: 09005aef8219eedd
256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
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256Mb: x16, x32 Mobile SDRAM
Timing Diagrams
Figure 41:
Single READ – without Auto Precharge
T0
T1
tCK
CLK
T2
T3
T4
T5
NOP2
NOP2
T6
T7
T8
tCL
tCH
tCKS
tCKH
tCMS
tCMH
CKE
COMMAND
ACTIVE
NOP
READ
tCMS
PRECHARGE
NOP
ACTIVE
NOP
tCMH
DQM
tAS
ROW
ADDR
tAS
ROW
COLUMN m
tAH
ALL BANKS
ROW
A10
tAS
BA[1:0]
tAH
ROW
SINGLE BANK
DISABLE AUTO PRECHARGE
tAH
BANK
BANK
BANK(S)
tOH
tAC
DQ
tLZ
tRCD
BANK
DOUT m
tHZ
CL
tRP
tRAS
tRC
DON’T CARE
UNDEFINED
Notes: 1. For this example, BL = 4, CL = 2, and the READ burst is followed by a manual PRECHARGE.
2. PRECHARGE command not allowed or tRAS would be violated.
See Table 11 on page 46.
PDF:09005aef8219eeeb/Source: 09005aef8219eedd
256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
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Timing Diagrams
Figure 42:
Single READ – with Auto Precharge
T0
T1
tCK
CLK
T2
T3
T4
T5
NOP2
READ
T6
T7
T8
tCL
tCH
tCKS
tCKH
tCMS
tCMH
CKE
COMMAND
ACTIVE
NOP
NOP2
tCMS
NOP
NOP
ACTIVE
NOP
tCMH
DQM
tAS
ROW
ADDR
tAS
ROW
COLUMN m
tAH
ENABLE AUTO PRECHARGE
ROW
A10
tAS
BA[1:0]
tAH
ROW
tAH
BANK
BANK
BANK
tOH
tAC
DQ
DOUT m
tRCD
tHZ
CL
tRP
tRAS
tRC
DON’T CARE
UNDEFINED
Notes: 1. For this example, BL = 4, CL = 2, and the READ burst is followed by a manual PRECHARGE.
2. PRECHARGE command not allowed or tRAS would be violated.
See Table 11 on page 46.
PDF:09005aef8219eeeb/Source: 09005aef8219eedd
256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
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Timing Diagrams
Figure 43:
Alternating Bank Read Accesses
T0
T1
tCK
CLK
T2
T3
T4
T5
NOP
ACTIVE
T6
T7
T8
READ
NOP
ACTIVE
tCL
tCH
tCKS
tCKH
tCMS
tCMH
CKE
COMMAND
ACTIVE
NOP
READ
tCMS
NOP
tCMH
DQM
tAS
ADDR
tAS
A10
tAH
COLUMN b 2
ROW
COLUMN m
ENABLE AUTO PRECHARGE
ROW
ENABLE AUTO PRECHARGE
ROW
tAS
BA[1:0]
tAH
ROW
ROW
ROW
tAH
BANK 0
BANK 0
BANK 3
tAC
tOH
tAC
DQ
tLZ
tRCD - bank 0
BANK 3
DOUT m
tAC
tOH
DOUT m + 1
BANK 0
tAC
tOH
DOUT m + 2
tAC
tOH
DOUT m + 3
tRP - bank 0
CL - bank 0
tAC
tOH
DOUT b
tRCD - bank 0
tRAS - bank 0
tRC - bank 0
tRCD - bank 4
tRRD
CL - bank 4
DON’T CARE
UNDEFINED
Notes: 1. For this example, BL = 4, CL = 2.
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Timing Diagrams
Figure 44:
READ – Continuous Page Burst
T0
T1
T2
tCL
CLK
T3
T4
T5
T6
((
))
((
))
tCK
tCH
tCKS
Tn + 3
Tn + 4
((
))
((
))
tCMS
tCMH
ACTIVE
NOP
READ
tCMS
NOP
NOP
NOP
NOP
tCMH
tAS
Address
tAH
ROW
tAS
tAS
NOP
BURST TERM
NOP
NOP
((
))
((
))
COLUMN m
tAH
((
))
((
))
ROW
A10
((
))
((
))
((
))
((
))
DQM/
DQML, DQMH
BA[1:0]
Tn + 2
tCKH
CKE
Command
Tn + 1
tAH
BANK
((
))
((
))
BANK
tAC
tAC
tOH
DOUT m
DQ
tLZ
tAC
tAC ( (
tOH ) )
tOH
DOUT m+1
DOUT
((
))
m+2
((
))
tAC
tAC
tOH
tOH
tOH
DOUT m-1
Dout m
DOUT m+1
tHZ
1024 (x16) locations within same row
tRCD
CAS Latency
Continuous page completed
Continuous-page burst does not self-terminate
2
Can use BURST TERMINATE command
Don’t Care
Undefined
Notes: 1. For this examples, CL = 2.
2. Page left open; no tRP.
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256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
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Timing Diagrams
Figure 45:
READ – DQM Operation
T0
T1
tCK
CLK
T2
T3
T4
T5
NOP
NOP
T6
T7
NOP
NOP
T8
tCL
tCH
tCKS
tCKH
tCMS
tCMH
CKE
COMMAND
ACTIVE
NOP
READ
tCMS
NOP
NOP
tCMH
DQM
tAS
ROW
ADDR
tAS
COLUMN m
tAH
ENABLE AUTO PRECHARGE
ROW
A10
tAS
BA[1:0]
tAH
DISABLE AUTO PRECHARGE
tAH
BANK
BANK
tAC
tOH
tAC
tAC
tOH
tOH
DOUT m + 2
DOUT m + 3
DQ
DOUT m
tLZ
tRCD
tHZ
CL
tLZ
tHZ
DON’T CARE
UNDEFINED
Notes: 1. For this example, CL = 2.
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Timing Diagrams
Figure 46:
WRITE – Without Auto Precharge
T0
tCK
CLK
T1
tCL
T2
T3
T4
T5
T6
NOP
NOP
NOP
NOP
T7
T8
T9
PRECHARGE
NOP
ACTIVE
tCH
tCKS
tCKH
tCMS
tCMH
CKE
COMMAND
ACTIVE
NOP
WRITE
tCMS tCMH
DQM
tAS
ADDR
ROW
tAS
ROW
COLUMN m
tAH
ALL BANKS
ROW
ROW
A10
tAS
BA[1:0]
tAH
tAH
BANK
DISABLE AUTO PRECHARGE
SINGLE BANK
BANK
BANK
tDS
tDH
DIN m
DQ
tDS
tDH
DIN m + 1
tDS
tDH
DIN m + 2
tRCD
tRAS
tDS
BANK
tDH
DIN m + 3
tWR2
tRP
tRC
DON’T CARE
Notes: 1. For this example, BL = 4, and the WRITE burst is followed by a manual PRECHARGE.
2. 15ns is required between and the PRECHARGE command, regardless of frequency.
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256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
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256Mb: x16, x32 Mobile SDRAM
Timing Diagrams
Figure 47:
WRITE – with Auto Precharge
T0
tCK
CLK
T1
T2
tCL
T3
T4
T5
T6
NOP
NOP
NOP
NOP
T7
T8
T9
NOP
NOP
ACTIVE
tCH
tCKS
tCKH
tCMS
tCMH
CKE
COMMAND
ACTIVE
NOP
WRITE
tCMS tCMH
DQM
tAS
ADDR
ROW
tAS
A10
ROW
COLUMN m
tAH
ENABLE AUTO PRECHARGE
ROW
ROW
tAS
BA[1:0]
tAH
tAH
BANK
BANK
BANK
tDS
tDH
DIN m
DQ
tDS
tDH
DIN m + 1
tDS
tDH
DIN m + 2
tRCD
tRAS
tDS
tDH
DIN m + 3
tWR2
tRP
tRC
DON’T CARE
UNDEFINED
Notes: 1. For this example, BL = 4.
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Timing Diagrams
Figure 48:
Single WRITE – Without Auto Precharge
T0
T1
tCK
CLK
T2
T3
T4
NOP3
NOP3
T5
T6
T7
T8
tCL
tCH
tCKS
tCKH
tCMS
tCMH
CKE
COMMAND
ACTIVE
NOP
WRITE
tCMS
PRECHARGE
NOP
ACTIVE
NOP
tCMH
DQM
tAS
ROW
ADDR
tAS
COLUMN m
tAH
ALL BANKS
ROW
A10
tAS
BA[1:0]
tAH
ROW
tAH
BANK
DISABLE AUTO PRECHARGE
SINGLE BANK
BANK
BANK
tDS
BANK
tDH
DIN m
DQ
tRCD
tRP
tWR2
tRAS
tRC
DON’T CARE
Notes: 1. For this example, BL = 1, and the WRITE burst is followed by a manual PRECHARGE.
2. 15ns is required between and the PRECHARGE command, regardless of frequency.
3. PRECHARGE command not allowed or tRAS would be violated.
See Table 11 on page 46.
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256Mb: x16, x32 Mobile SDRAM
Timing Diagrams
Figure 49:
Single WRITE – with Auto Precharge
T0
T1
tCK
CLK
T2
T3
T4
T5
NOP3
WRITE
T6
T7
T8
NOP
NOP
ACTIVE
T9
tCL
tCH
tCKS
tCKH
tCMS
tCMH
CKE
COMMAND
NOP3
ACTIVE
NOP3
tCMS
NOP
NOP
tCMH
DQM
tAS
ADDR
tAS
ROW
COLUMN m
tAH
ENABLE AUTO PRECHARGE
ROW
A10
tAS
BA[1:0]
tAH
ROW
ROW
tAH
BANK
BANK
tDS
DQ
BANK
tDH
DIN m
tRCD
tRAS
tWR
tRP
tRC
DON’T CARE
Notes: 1. For this example, BL = 1, and the WRITE burst is followed by a manual PRECHARGE.
2. 15ns is required between and the PRECHARGE command, regardless of frequency.
3. WRITE command not allowed or tRAS would be violated.
See Table 11 on page 46.
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256Mb: x16, x32 Mobile SDRAM
Timing Diagrams
Figure 50:
Alternating Bank Write Accesses
T0
T1
tCK
CLK
T2
T3
T4
T5
T6
T7
T8
T9
WRITE
NOP
NOP
ACTIVE
tCL
tCH
tCKS
tCKH
tCMS
tCMH
CKE
COMMAND
ACTIVE
NOP
WRITE
tCMS
NOP
ACTIVE
NOP
tCMH
DQM
tAS
ADDR
tAS
tAH
tAS
2
COLUMN b
ROW
COLUMN m
ENABLE AUTO PRECHARGE
ROW
ENABLE AUTO PRECHARGE
ROW
A10
BA[1:0]
tAH
ROW
ROW
ROW
tAH
BANK 0
BANK 0
tDS
tDH
DIN m
DQ
BANK 1
tDS
tDH
DIN m + 1
tDS
BANK 1
tDH
tDS
DIN m + 2
tDH
DIN m + 3
tDS
DIN b
tWR - bank 0
tRCD - bank 0
tRAS - bank 0
tRC - bank 0
tDH
BANK 0
tDS
tDH
DIN b + 1
tDS
tDH
DIN b + 2
tRP - bank 0
tDS
tDH
DIN m + 3
tRCD - bank 0
tWR - bank 1
tRCD - bank 1
tRRD
DON’T CARE
Notes: 1. For this example, BL = 4.
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256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
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Timing Diagrams
Figure 51:
WRITE – Continuous Page Burst
T0
T1
T2
tCL
CLK
T3
T4
T5
tCH
tCKS
tCKH
Command
tCMH
ACTIVE
NOP
WRITE
NOP
NOP
((
))
((
))
NOP
tCMS tCMH
tAS
A10
NOP
BURST TERM
NOP
((
))
((
))
COLUMN m1
tAH
((
))
((
))
ROW
tAS
BA[1:0]
tAH
ROW
tAS
Tn + 3
((
))
((
))
DQM/
DQML, DQMH
Addresss
Tn + 2
((
))
((
))
CKE
tCMS
Tn + 1
((
))
((
))
tCK
tAH
BANK
((
))
((
))
BANK
tDS
tDH
DIN m
DQ
tDS
tDH
DIN m + 1
tRCD
tDS
tDH
DIN m + 2
tDS
tDH
DIN m +
((
))
3((
))
tDS
tDH
DIN m - 1
1024 (x16) locations within same row
Continuous-page burst does
not self-terminate.
Can use BURST TERMINATE
command to stop.2, 3
Continuous page completed
Don’t Care
Notes: 1.
2.
3.
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256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
x16: A11 and A12 = “Don’t Care”; x8: A12 = “Don’t Care.”
must be satisfied prior to PRECHARGE command.
Page left open; no tRP.
tWR
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256Mb: x16, x32 Mobile SDRAM
Timing Diagrams
Figure 52:
WRITE – DQM Operation
T0
T1
tCK
CLK
T2
T3
T4
T5
NOP
NOP
NOP
T6
T7
NOP
NOP
tCL
tCH
tCKS
tCKH
tCMS
tCMH
CKE
COMMAND
ACTIVE
NOP
WRITE
tCMS tCMH
DQM
tAS
ADDR
ROW
tAS
A10
COLUMN m
tAH
ENABLE AUTO PRECHARGE
ROW
tAS
BA[1:0]
tAH
DISABLE AUTO PRECHARGE
tAH
BANK
BANK
tDS
tDH
tDS
DIN m
DQ
tDH
DIN m + 2
tDS
tDH
DIN m + 3
tRCD
DON’T CARE
Notes: 1. For this example, BL = 4.
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256Mb: x16, x32 Mobile SDRAM
Package Dimensions
Package Dimensions
Figure 53:
54-Ball VFBGA (8mm x 9mm)
0.65 ±0.05
SEATING
PLANE
0.10 A
A
SOLDER BALL MATERIAL:
SAC105 (98.5% Sn, 1% Ag, 0.5% Cu)
SUBSTRATE MATERIAL: PLASTIC LAMINATE
MOLD COMPOUND: EPOXY NOVOLAC
54X Ø0.45
SOLDER BALL
DIAMETER REFERS
TO POST REFLOW
CONDITION. THE PREREFLOW DIAMETER
IS 0.42 ON A 0.40
SMD BALL PAD.
6.40
MICRON LOGO
TO BE LASED
BALL A1 ID
BALL A1 ID
BALL A1
0.80
TYP
4.50 ±0.05
BALL A9
CL
6.40
9.00 ± 0.10
3.20
0.80 TYP
CL
3.20
4.00 ±0.05
1.00 MAX
8.00 ±0.10
Notes: 1. All dimensions are in millimeters.
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256Mb: x16, x32 Mobile SDRAM
Package Dimensions
Figure 54:
90-Ball VFBGA (8mm x 13mm)
0.65 ±0.05
Seating
plane
Solder ball material:
SAC105 (98.5% Sn, 1%Ag, 0.5% Cu)
A
0.1 A
90X 0.45
Dimensions apply
to solder balls postreflow. Pre-reflow
balls are Ø0.42 on
Ø0.4 SMD ball pads.
8 ±0.1
Substrate material: plastic laminate
Mold compound: epoxy novolac
4 ±0.05
Ball A1 ID
9
8
7
3
2
Ball A1 ID
1
A
B
C
D
5.6
E
F
11.2
G
H
0.8 TYP
13 ±0.1
J
K
L
M
N
6.5 ±0.05
P
R
0.8 TYP
3.2
6.4
1.0 MAX
Notes: 1. All dimensions are in millimeters.
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 and the Micron logo are trademarks of Micron Technology, Inc.
All other trademarks are the property of their respective owners.
This data sheet contains minimum and maximum limits specified over the 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.
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256Mb: x16, x32 Mobile SDRAM
Revision History
Revision History
Rev. G, Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 06/09
• Table 10, “DC Electrical Characteristics and Operating Conditions,” on page 45:
Updated IOZ specification.
Rev. F, Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 04/07
• Changed wording in Note 1 in the “Options” section on page 1.
• Changed CL = 2, -75 and -8 access times from “6ns” and “7ns” to “9ns” in Table 2 on
page 1.
• Added “Revision :G” to Figure 1 on page 5.
• Changed refresh counter from “12” to “13” and changed Bank0 Memory Array from
“8,192” to “4,096” in Figure 3 on page 7.
• Changed E2, K2 to “DNU” and added the following sentence in the: “TEST pin must
be tied to VssQ in normal operation” in Table 3 on page 10.
• Added the following sentence to the “Input/output mask” description in Table 3 on
page 10: “DQM loading is designed to match that of DQ balls.”
• Removed all the text after the first sentence in the “Initialization” section on page 12.
• Removed the first seven words in the “Mode Register” section on page 13.
• Removed “(sequential or interleaved)” and “...the specified time...” in the
“Mode Register” section on page 13.
• Changed “M13” and “M12” to “M13” and “M14” and deleted a column in the
“Operating Mode” table in Figure 3 on page 7.
• Removed the notes under Table 4 on page 15.
• Corrected the “Operating Mode” table in Figure 6 on page 14.
• Removed the following text under the “Operating Mode” section on page 16: “or test
modes” and “The programmed BL applies to both READ and WRITE bursts.”
• Removed “(nonburst)” under the “Write Burst Mode” section on page 16.
• Removed the last two sentences in the first paragraph and removed
“(BA1=1, AB0=0),” in the second paragraph in the “Low-Power Extended Mode Register (EMR) Definition” section on page 16.
• Changed the “Low-Power Extended Mode Register (EMR) Definition” heading to
“Extended Mode Register (EMR)” on page 16.
• Moved Figure 7 to page 16.
• Changed the title of Figure 7 on page 16 to “EMR Definition.”
• Removed all bank address references from the “PASR Self-Refresh Coverage” in
Figure 7 on page 16.
• Replace the “Temperature-Compensated Self Refresh (TCSR)” section on page 17.
• Removed the second sentence in the “Partial Array Self-Refresh” section on page 18.
• Replaced Table 5 on page 19 and all the associated notes.
• Removed last paragraph and added “A0–A12” in the first sentence in the “Load Mode
Register” section on page 20.
• Removed “...and the DQ balls tri-state” from the “COMMAND INHIBIT” section on
page 19.
• Moved the “Auto Precharge” section to page 21.
• Added a second paragraph in the “Deep Power Down” section on page 22.
• Added “BL = 2” to the note under Figure 20 on page 31.
• Added “BL = 2” to the note under Figure 22 on page 32.
• Changed “(see Figure 23)” to “(see Figure 25)” on page 34.
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256Mb: x16, x32 Mobile SDRAM
Revision History
•
•
•
•
•
•
Moved Figure 25 to page 34.
Removed the “In order to exit deep power down...” paragraph on page 35.
Replaced text in note 9 and removed “Deep power down” rows in Table 7 on page 41.
Added note 9 to tAC and note 27 to tOHN in Table 11 on page 46.
Changed tXSR from “67.5” to “80” in Table 11 on page 46.
Changed “9” to “8” for tAC (2) -75, and tCK (2) -75 from “10” to “9” in Table 11 on
page 46.
• Replaced note 30 and 31 in the “Notes” section on page 52.
• Moved Figure 34 to page 54.
• Removed note 1 from Figure 38 on page 58.
Rev. E, Production. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 03/07
• Changed ball D7 from “VDDQ” to “VSSQ” in Figure 4 on page 8.
Rev. D, Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 02/07
• Removed CL = 1 from Table 2 on page 1, Figure 6 on page 14, Figure 7 on page 16,
Figure 12 on page 25, Figure 13 on page 26, Figure 16 on page 28, Figure 17 on
page 29, Table 11 on page 46, Table 12 on page 47.
Rev. C, Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 09/06
• Added a “For burst length of 16 or continuous page burst, contact factory for availability” in Features section on page 1.
• Changed “Burst Length = 1” in the IDD1 row in Table 13 and Table 14.
• Changed all instances of “HDQM” with “UDQM.”
• Changed all instances of “DQM0-3” to “DQM” in Figure 36 through Figure 52.
• Removed all instances of continuous page burst after page 1.
• Added changed burst length “16” and “continuous” to “Reserved” in Figure 6.
• Removed note specifying “E14 and E13 (BA1 and BA0) must be “1, 0” to select the
extended mode register (vs. the standard mode register) from Figure 8.
• Changed the following sentence in the “Extended Mode Register (EMR)” on page 16:
“The low-power EMR must be loaded when all banks are idle and no burst are in
progress.”
• Removed the following note from Figure 53 and Figure 54: “Green packaging composition is available upon request.”
Rev. B, Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 09/06
•
•
•
•
•
•
•
•
•
•
•
•
PDF:09005aef8219eeeb/Source: 09005aef8219eedd
256mb_x16_sdram_y36m_1.fm - Rev G 6/09 EN
Added Note 1 to Figure 8, page 17.
Updated Table 15 values, page 50.
Removed all instances of -10 speed grade.
Changed CL = 2 from 104 MHz to 100 MHz.
Changed “Refresh count” for 8 Meg x 32 to 8K from 4K in Table 1.
Added “E2” row to Table 3.
Removed the following from sentence two in the “General Description” section: “This
architecture is compatible with the 2n rule of prefetch architecture.”
Removed all instances of “full” page burst and replaced them with “continuous” page
burst.
Added the following note to the “Features” section on page 1: “Contact factory for
availability.”
Added a “Power” section to “Options” on page 1.
Replaced old part numbering table with Figure 1.
Changed the clock rate on -75 and -8 for CL = 2 from 111 to 100 in Table 2.
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Revision History
• Changed the “8” address lines going into the “column address counter/Latch” to “9”
in Figure 2.
• Changed all references of 13 to 12 and changed the “8” address lines going into the
“column address counter/Latch” to “9” in Figure 3.
• Changed the “8” address lines going into the “column address counter/Latch” to “9”
in Figure 2.
• Deleted “(4 Meg x32 x4 banks)” from the first sentence of the “Functional Description” section.
• Removed the following sentence from the “Mode Register (MR) section: “M12 and
M13 should be set to zero to prevent the EMR from being programmed.”
• Added A12 to Figure 6.
• Added notes 2? and 2 to Figure 8.
• Removed Table 5, “CAS Latency.”
• Removed all notes except note 2 and added note 1 to Table 5.
• Removed all text references to the “2n rule.”
• Changed the following items in Table 12: Changed tAC(2) from 7/8 to 9ns for -75 and 8 speed grades, changed tCK(2) from 9 tp 10ns for -75 and -8 speed grades, and
changed tHZ(2) from 7/8 to 9ns for -75 and -8 speed grades.
• Added Table 14 for x32 specifications.
• Changed the following specifications in Table 16: CLK 1.5 (MIN) 4.5 (MAX), Input 2.0
(MIN) 4.5 (MAX), DQs 2.0 (MIN) 6.0 (MAX)
• Added Figure 33.
• Deleted first line of “Solder Ball Material” in Figure 52.
• Changed “Burst Length = 1” in the IDD1 row in Table 13 and Table 14.
• Added a “Contact factory for availability” note to Figure 6.
Rev. A, Advance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4/06
• Initial release
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