64Mb: 4 Meg x 16 Async/Page/Burst CellularRAM 1.0 Memory
Features
Async/Page/Burst CellularRAM
TM
1.0 Memory
MT45W4MW16B*
*Note: Not recommended for new designs.
For the latest data sheet, refer to Micron’s Web site:
http://www.micron.com/products/psram/
Features
• Single device supports asynchronous, page, and
burst operations
• Random access time: 70ns
• V
CC
, V
CC
Q voltages
1.70V–1.95V V
CC
1.70V–3.30V V
CC
Q
• Page mode read access
Sixteen-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: 80 MHz (
t
CLK = 12.5ns)
Burst initial latency: 50ns (4 clocks) @ 80 MHz
t
ACLK: 9ns @ 80 MHz
• Low power consumption
Asynchronous READ: <25mA
Intrapage READ: <15mA
Initial access, burst READ:
(50ns [4 clocks] @ 80 MHz) < 35mA
Continuous burst READ: <15mA
Standby: 120µA – standard
100µA – low-power option
Deep power-down: <10µA (TYP @ 25°C)
• Low-power features
Temperature-compensated refresh (TCR)
Partial-array refresh (PAR)
Deep power-down (DPD) mode
Figure 1:
Ball Assignment – 54-Ball VFBGA
1
A
B
C
D
E
F
G
H
J
LB#
2
OE#
3
A0
4
A1
5
A2
6
CRE
DQ8
UB#
A3
A4
CE#
DQ0
DQ9
DQ10
A5
A6
DQ1
DQ2
V
SS
Q
DQ11
A17
A7
DQ3
V
CC
V
CC
Q
DQ12
A21
A16
DQ4
V
SS
DQ14
DQ13
A14
A15
DQ5
DQ6
DQ15
A19
A12
A13
WE#
DQ7
A18
A8
A9
A10
A11
A20
WAIT
CLK
ADV#
NC
NC
NC
Top View
(Ball Down)
Options (continued)
• Frequency
66 MHz
80 MHz
• Standby power
Standard
Low-power
• Operating temperature range
Wireless (-30°C to +85°C)
Industrial (-40°C to +85°C)
2. Contact factory.
Designator
6
8
None
L
WT
3
IT
2
Options
• Configuration:
4 Meg x 16
• Package
54-ball VFBGA (standard)
54-ball VFBGA (lead-free)
• Timing
70ns access
85ns access
PDF: 09005aef80be1fbd/Source: 09005aef80be2036
Burst CellularRAM_1.fm - Rev. G 10/05 EN
Designator
MT45W4MW16B
1
FB
BB
2
-70
-85
Notes: 1. Not recommended for new designs.
3. -30°C exceeds the CellularRAM Working
Group 1.0 specification of -25°C.
Part Number Example:
MT45W4MW16BFB-708LWT
1
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2003 Micron Technology, Inc. All rights reserved.
Products and specifications discussed herein are subject to change by Micron without notice.
64Mb: 4 Meg x 16 Async/Page/Burst CellularRAM 1.0 Memory
Table of Contents
Table of Contents
General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Bus Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Part-Numbering Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Valid Part Number Combinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Device Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Power-Up Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Bus Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Asynchronous Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Page Mode READ Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Burst Mode Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Mixed-Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
WAIT Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
LB#/UB# Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Low-Power Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Standby Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Temperature-Compensated Refresh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Partial-Array Refresh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Deep Power-Down Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Configuration Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Access Using CRE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Software Access. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Bus Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Burst Length (BCR[2:0]) Default = Continuous Burst . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Burst Wrap (BCR[3]) Default = Burst No Wrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Output Impedance (BCR[5]) Default = Outputs Use Full Drive Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
WAIT Configuration (BCR[8]) Default = WAIT Transitions One Clock Before Data Valid/Invalid . . . . . . . . .23
WAIT Polarity (BCR[10]) Default = WAIT Active HIGH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Latency Counter (BCR[13:11]) Default = Three-Clock Latency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Operating Mode (BCR[15]) Default = Asynchronous Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Refresh Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Partial-Array Refresh (RCR[2:0]) Default = Full Array Refresh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Deep Power-Down (RCR[4]) Default = DPD Disabled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Temperature-Compensated Refresh (RCR[6:5]) Default = +85°C Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Page Mode Operation (RCR[7]) Default = Disabled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
Maximum and Typical Standby Currents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
Timing Diagrams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Revision History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
PDF: 09005aef80be1fbd/Source: 09005aef80be2036
Burst CellularRAMTOC.fm - Rev. G 10/05 EN
2
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2003 Micron Technology, Inc. All rights reserved.
64Mb: 4 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:
Ball Assignment – 54-Ball VFBGA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Functional Block Diagram – 4 Meg x 16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Part Number Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Power-Up Initialization Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
READ Operation (ADV = LOW) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
WRITE Operation (ADV = LOW) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Page Mode READ Operation (ADV = LOW) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Burst Mode READ (4-word Burst) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Burst Mode WRITE (4-word Burst) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Wired or WAIT Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Refresh Collision During READ Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Refresh Collision During WRITE Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Configuration Register WRITE in Asynchronous Mode Followed by READ ARRAY Operation . . . .17
Configuration Register WRITE in Synchronous Mode Followed by READ ARRAY Operation . . . . .18
Load Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Read Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
Bus Configuration Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
WAIT Configuration (BCR[8] = 0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
WAIT Configuration (BCR[8] = 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
WAIT Configuration During Burst Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Latency Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Refresh Configuration Register Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Typical Refresh Current vs. Temperature (I
TCR
) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
AC Input/Output Reference Waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Output Load Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Initialization Period . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Asynchronous READ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
Asynchronous READ Using ADV#. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
Page Mode READ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
Single-Access Burst READ Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
4-Word Burst READ Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
4-Word Burst READ Operation (with LB#/UB#) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
READ Burst Suspend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
Continuous Burst READ Showing an Output Delay with BCR[8] = 0 for End-of-Row Condition . . .45
CE#-Controlled Asynchronous WRITE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
LB#/UB#-Controlled Asynchronous WRITE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
WE#-Controlled Asynchronous WRITE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
Asynchronous WRITE Using ADV#. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
Burst WRITE Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
Continuous Burst WRITE Showing an Output Delay with BCR[8] = 0 for End-of-Row Condition . .51
Burst WRITE Followed by Burst READ. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
Asynchronous WRITE Followed by Burst READ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
Asynchronous WRITE Followed By Burst READ – ADV# LOW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
Burst READ Followed by Asynchronous WRITE (WE#-Controlled) . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
Burst READ Followed by Asynchronous WRITE Using ADV#. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56
Asynchronous WRITE Followed by Asynchronous READ – ADV# LOW. . . . . . . . . . . . . . . . . . . . . . . . .57
Asynchronous WRITE Followed by Asynchronous READ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58
54-Ball VFBGA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59
PDF: 09005aef80be1fbd/Source: 09005aef80be2036
Burst CellularRAMLOF.fm - Rev. G 10/05 EN
3
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2003 Micron Technology, Inc. All rights reserved.
64Mb: 4 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:
Table 17:
Table 18:
Table 19:
Table 20:
Table 21:
Table 22:
Table 23:
Table 24:
Table 25:
Table 26:
Table 27:
Table 28:
Table 29:
Table 30:
Table 31:
Table 32:
Table 33:
Table 34:
Table 35:
Table 36:
Table 37:
Table 38:
Table 39:
Table 40:
Table 41:
Table 42:
Table 43:
Table 44:
Table 45:
Table 46:
VFBGA Ball Descriptions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Bus Operations – Asynchronous Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Bus Operations – Burst Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Sequence and Burst Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Latency Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
64Mb Address Patterns for PAR (RCR[4] = 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
Electrical Characteristics and Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Maximum Standby Currents for Applying PAR and TCR Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
Maximum Standby Currents for Applying PAR and TCR Settings – Low-Power (L) . . . . . . . . . . . . . .30
Deep Power-Down Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Capacitance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Output Load Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Asynchronous READ Cycle Timing Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
Burst READ Cycle Timing Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
Asynchronous WRITE Cycle Timing Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Burst WRITE Cycle Timing Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
Initialization Timing Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Asynchronous READ Timing Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
Asynchronous READ Timing Parameters Using ADV#. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
Asynchronous READ Timing Parameters – Page Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
Burst READ Timing Parameters – Single Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
Burst READ Timing Parameters – 4-Word Burst . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
Burst READ Timing Parameters – 4-Word Burst with LB#/UB#. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Burst READ Timing Parameters – Burst Suspend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
Burst READ Timing Parameters – BCR[8] = 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
Asynchronous WRITE Timing Parameters – CE#-Controlled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
Asynchronous WRITE Timing Parameters – LB#/UB#-Controlled . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
Asynchronous WRITE Timing Parameters – WE#-Controlled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
Asynchronous WRITE Timing Parameters Using ADV#. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
Burst WRITE Timing Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
Burst WRITE Timing Parameters – BCR[8] = 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
WRITE Timing Parameters – Burst WRITE Followed by Burst READ . . . . . . . . . . . . . . . . . . . . . . . . . . .52
READ Timing Parameters – Burst WRITE Followed by Burst READ . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
WRITE Timing Parameters – Async WRITE Followed by Burst READ. . . . . . . . . . . . . . . . . . . . . . . . . . .53
READ Timing Parameters – Async WRITE Followed by Burst READ. . . . . . . . . . . . . . . . . . . . . . . . . . . .53
Asynchronous WRITE Timing Parameters – ADV# LOW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
Burst READ Timing Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
Burst READ Timing Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
Asynchronous WRITE Timing Parameters – WE#-Controlled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
Burst READ Timing Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56
Asynchronous WRITE Timing Parameters Using ADV#. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56
WRITE Timing Parameters – ADV# LOW. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
READ Timing Parameters – ADV# LOW. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
WRITE Timing Parameters – Async WRITE Followed by Async READ . . . . . . . . . . . . . . . . . . . . . . . . . .58
READ Timing Parameters – Async WRITE Followed by Async READ . . . . . . . . . . . . . . . . . . . . . . . . . . .58
PDF: 09005aef80be1fbd/Source: 09005aef80be2036
Burst CellularRAMLOT.fm - Rev. G 10/05 EN
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Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2003 Micron Technology, Inc. All rights reserved.
64Mb: 4 Meg x 16 Async/Page/Burst CellularRAM 1.0 Memory
General Description
General Description
Micron
®
CellularRAM™ products are high-speed, CMOS PSRAM memories developed
for low-power, portable applications. The MT45W4MW16BFB is a 64Mb DRAM core
device organized as 4 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 offerings.
To operate seamlessly 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 per-
formance.
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 used 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) is used to
adjust the refresh rate according to the case temperature. The refresh rate can be
decreased 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.
Figure 2:
Functional Block Diagram – 4 Meg x 16
A[21:0]
Address Decode
Logic
4,096K x 16
DRAM
Memory
Array
Input/
Output
MUX
and
Buffers
DQ[7:0]
DQ[15:8]
Refresh Configuration
Register (RCR)
Bus Configuration
Register (BCR)
CE#
WE#
OE#
CLK
ADV#
CRE
WAIT
LB#
UB#
Control
Logic
Note:
Functional block diagrams illustrate simplified device operation. See truth table, ball
descriptions, and timing diagrams for detailed information.
PDF: 09005aef80be1fbd/Source: 09005aef80be2036
Burst CellularRAM_2.fm - Rev. G 10/05 EN
5
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2003 Micron Technology, Inc. All rights reserved.
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