32Mb: 2 Meg x 16 Async/Page/Burst CellularRAM 1.0 Memory
Features
Async/Page/Burst
CellularRAM
®
1.0 Memory
MT45W2MW16BGB
Features
• Single device supports asynchronous, page, and
burst operations
• Random access time: 70ns
• V
CC
, V
CC
Q voltages
–
1.7–1.95V V
CC
–
1.7–3.6V V
CC
Q
• Page mode read access
–
16-word page size
–
Interpage read access: 70ns
–
Intrapage read access: 20ns
• Burst mode write access: continuous burst
• Burst mode read access
–
4, 8, or 16 words or continuous burst
–
MAX clock rate: 104 MHz (
t
CLK = 9.62ns)
–
Burst initial latency: 38.5ns (4 clocks) at 104 MHz
–
t
ACLK: 7ns at 104 MHz
• Low power consumption
–
Asynchronous read: <20mA
–
Intrapage read: <15mA
–
Intrapage read initial access, burst read:
(38.5ns [4 clocks] at 104 MHz) <40mA
–
Continuous burst read: <25mA
–
Standby: <110µA
–
Deep power-down: <10µA (TYP at 25°C)
• Low-power features
–
Temperature-compensated refresh (TCR)
–
On-chip temperature sensor
–
Partial-array refresh (PAR)
–
Deep power-down (DPD) mode
Figure 1:
54-Ball VFBGA Ball Assignment
1
A
B
C
D
E
F
G
H
J
2
3
4
5
6
LB#
DQ8
DQ9
OE#
UB#
DQ10
A0
A3
A5
A17
NC
A14
A12
A9
ADV#
A1
A4
A6
A7
A16
A15
A13
A10
NC
A2
CE#
DQ1
DQ3
DQ4
DQ5
WE#
A11
NC
CRE
DQ0
DQ2
VCC
VSS
DQ6
DQ7
A20
NC
V
SS
Q DQ11
V
CC
Q DQ12
DQ14 DQ13
DQ15
A18
WAIT
A19
A8
CLK
Top view
(Ball down)
Options (continued)
• Standby power
–
Standard
• Low power
• Operating temperature range
–
Wireless (–30°C to +85°C)
–
Industrial (–40°C to +85°C)
Designator
None
L
WT
1
IT
2
Options
• Configuration
–
2 Meg x 16
• Package
–
54-ball VFBGA (“green”)
• Access time
–
70ns
• Frequency
–
80 MHz
–
104 MHz
PDF: 09005aef82832fa2/Source: 09005aef82832f5f
32mb_burst_cr1_0_p24z_1.fm - Rev. E 9/08 EN
Designator
MT45W2MW16B
GB
-70
8
1
Notes: 1. –30°C exceeds the CellularRAM Workgroup
1.0 specification of –25°C.
2. Contact factory for availability.
Part Number Example:
MT45W2MW16BGB-701WT
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2007 Micron Technology, Inc. All rights reserved.
1
Products and specifications discussed herein are subject to change by Micron without notice.
32Mb: 2 Meg x 16 Async/Page/Burst CellularRAM 1.0 Memory
Table of Contents
Table of Contents
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Functional Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Ball Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Bus Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Part Numbering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Valid Part Number Combinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Device Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Power-Up Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Bus Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Asynchronous Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Page Mode READ Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Burst Mode Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Mixed-Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
WAIT Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
LB#/UB# Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Low-Power Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Standby Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Temperature-Compensated Refresh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Partial-Array Refresh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Deep Power-Down Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Configuration Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
Access Using CRE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
Software Access to the Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Bus Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Burst Length (BCR[2:0]) Default = Continuous Burst . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Burst Wrap (BCR[3]) Default = Burst No Wrap (Within Burst Length) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Output Impedance (BCR[5]) Default = Outputs Use Full Drive Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
WAIT Configuration (BCR[8]) Default = WAIT Transitions One Clock Before Data Valid/Invalid . . . . . . . . .28
WAIT Polarity (BCR[10]) Default = WAIT Active HIGH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Latency Counter (BCR[13:11]) Default = Three-Clock Latency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Operating Mode (BCR[15]) Default = Asynchronous Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Refresh Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Partial-Array Refresh (RCR[2:0]) Default = Full Array Refresh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Deep Power-Down (RCR[4]) Default = DPD Disabled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Page Mode Operation (RCR[7]) Default = Disabled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Maximum and Typical Standby Currents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
Timing Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
Timing Diagrams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
Package Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
Revision History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61
PDF: 09005aef82832fa2/Source: 09005aef82832f5f
32mb_burst_c1_0_p24zTOC.fm - Rev. E 9/08 EN
2
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2006 Micron Technology, Inc. All rights reserved.
32Mb: 2 Meg x 16 Async/Page/Burst CellularRAM 1.0 Memory
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:
54-Ball VFBGA Ball Assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Functional Block Diagram – 2 Meg x 16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Part Number Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Power-Up Initialization Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
READ Operation (ADV = LOW) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
WRITE Operation (ADV = LOW) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Page Mode READ Operation (ADV = LOW) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Burst Mode READ (4-Word Burst) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Burst Mode WRITE (4-Word Burst) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Wired-OR WAIT Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Refresh Collision During READ Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Refresh Collision During WRITE Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Asynchronous Mode Configuration Register WRITE Followed by READ ARRAY Operation . . . . . .20
Synchronous Mode Configuration Register WRITE Followed by READ ARRAY Operation . . . . . . .21
Asynchronous Mode Configuration Register READ Followed by READ ARRAY Operation . . . . . . .22
Synchronous Mode Configuration Register READ Followed by READ ARRAY Operation . . . . . . . .23
Load Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Read Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Bus Configuration Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
WAIT Configuration (BCR[8] = 0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
WAIT Configuration (BCR[8] = 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
WAIT Configuration During Burst Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Latency Counter (Variable Latency, No Refresh Collision) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
Refresh Configuration Register Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Typical Refresh Current vs. Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
AC Input/Output Reference Waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Output Load Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Initialization Period . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
Asynchronous READ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
Asynchronous READ Using ADV# . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
Page Mode READ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
Single-Access Burst READ Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
4-Word Burst READ Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
READ Burst Suspend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
Output Delay in Continuous Burst READ with BCR[8] = 0 for End-of-Row Condition . . . . . . . . . . .46
CE#-Controlled Asynchronous WRITE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
LB#/UB#-Controlled Asynchronous WRITE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
WE#-Controlled Asynchronous WRITE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
Asynchronous WRITE Using ADV# . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
Burst WRITE Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
Output Delay in Continuous Burst WRITE with BCR[8] = 0 for End-of-Row Condition . . . . . . . . . .52
Burst WRITE Followed by Burst READ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
Asynchronous WRITE Followed by Burst READ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
Asynchronous WRITE Followed by Burst READ with ADV# LOW . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
Burst READ Followed by Asynchronous WRITE (WE#-Controlled) . . . . . . . . . . . . . . . . . . . . . . . . . . . .56
Burst READ Followed by Asynchronous WRITE Using ADV# . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
Asynchronous WRITE Followed by Asynchronous READ with ADV# LOW . . . . . . . . . . . . . . . . . . . . .58
Asynchronous WRITE Followed by Asynchronous READ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59
54-Ball VFBGA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
PDF: 09005aef82832fa2/Source: 09005aef82832f5f
32mb_burst_c1_0_p24zLOF.fm - Rev. E 9/08 EN
3
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2007 Micron Technology, Inc. All rights reserved.
32Mb: 2 Meg x 16 Async/Page/Burst CellularRAM 1.0 Memory
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:
VFBGA Ball Descriptions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Bus Operations: Asynchronous Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Bus Operations: Burst Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Sequence and Burst Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Latency Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
32Mb Address Patterns for PAR (RCR[4] = 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Electrical Characteristics and Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
Partial-Array Refresh Specifications and Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
Deep Power-Down Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Capacitance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Asynchronous READ Cycle Timing Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
Burst READ Cycle Timing Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Asynchronous WRITE Cycle Timing Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
Burst WRITE Cycle Timing Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
Initialization Timing Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
PDF: 09005aef82832fa2/Source: 09005aef82832f5f
32mb_burst_c1_0_p24zLOT.fm - Rev. E 9/08 EN
4
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2007 Micron Technology, Inc. All rights reserved.
32Mb: 2 Meg x 16 Async/Page/Burst CellularRAM 1.0 Memory
General Description
General Description
Micron
®
CellularRAM
®
is a high-speed, CMOS PSRAM memory device developed for
low-power, portable applications. The MT45W2MW16BGB is a 32Mb DRAM core
device organized as 2 Meg x 16 bits. This device includes an industry-standard
burst mode Flash interface that dramatically increases READ/WRITE bandwidth
compared with other low-power SRAM or pseudo-SRAM (PSRAM) offerings.
For seamless operation on a burst Flash bus, CellularRAM products incorporate a trans-
parent self refresh mechanism. The hidden refresh requires no additional support from
the system memory controller and has no significant impact on device READ/WRITE
performance.
Two user-accessible control registers define device operation. The bus configuration
register (BCR) defines how the CellularRAM device interacts with the system memory
bus and is nearly identical to its counterpart on burst mode Flash devices. The refresh
configuration register (RCR) is used to control how refresh is performed on the DRAM
array. These registers are automatically loaded with default settings during power-up
and can be updated anytime during normal operation.
Special attention has been focused on standby current consumption during self refresh.
CellularRAM products include three system-accessible mechanisms to minimize
standby current. Partial-array refresh (PAR) limits refresh to only that part of the DRAM
array that contains essential data. Temperature-compensated refresh (TCR) uses an on-
chip sensor to adjust the refresh rate to match the device temperature. The refresh rate
decreases at lower temperatures to minimize current consumption during standby.
Deep power-down (DPD) halts the REFRESH operation altogether and is used when no
vital information is stored in the device. These three refresh mechanisms are accessed
through the RCR.
PDF: 09005aef82832fa2/Source: 09005aef82832f5f
32mb_burst_cr1_0_p24z_2.fm - Rev. E 9/08 EN
5
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2007 Micron Technology, Inc. All rights reserved.
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