Preliminary Data Sheet
168-pin Low Profile Registered SDRAM DIMMs
256MB, 512MB, 1GB
Features
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JEDEC Standard 168-pin Registered SDRAM DIMM
Low Profile Versions for 1U Rack Mount Systems
PC100 and PC133 Speed Grades
Registered Inputs Minimize Loading
Phase Lock Loop (PLL) Clock Driver for Improved
Timing
Supports CAS Latency = 2, 3
On-board Serial Presence Detect (SPD)
Single 3.3V
±
0.3V Power Supply
Pin
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
Symbol
Vss
DQ0
DQ1
DQ2
DQ3
Vdd
DQ4
DQ5
DQ6
DQ7
DQ8
Vss
DQ9
DQ10
DQ11
DQ12
DQ13
Vdd
DQ14
DQ15
CB0
CB1
Vss
NC
NC
Vdd
WE#
DQMB0
DQMB1
S0#
DNU
Vss
A0
A2
A4
A6
A8
A10/AP
BA1
Vdd
Vdd
CK0
Pin
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
Symbol
Vss
DNU
S2#
DQMB2
DQMB3
DNU
Vdd
NC
NC
CB2
CB3
Vss
DQ16
DQ17
DQ18
DQ19
Vdd
DQ20
NC
NC
CKE1*
Vss
DQ21
DQ22
DQ23
Vss
DQ24
DQ25
DQ26
DQ27
Vdd
DQ28
DQ29
DQ30
DQ31
Vss
CK2*
NC
WP
SDA
SCL
Vdd
Pin
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
Symbol
Vss
DQ32
DQ33
DQ34
DQ35
Vdd
DQ36
DQ37
DQ38
DQ39
DQ40
Vss
DQ41
DQ42
DQ43
DQ44
DQ45
Vdd
DQ46
DQ47
CB4
CB5
Vss
NC
NC
Vdd
CAS#
DQMB4
DQMB5
S1#
RAS#
Vss
A1
A3
A5
A7
A9
BA0
A11
Vdd
CK1*
A12
Pin
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
Symbol
Vss
CKE0
S3#
DQMB6
DQMB7
RFU
Vdd
NC
NC
CB6
CB7
Vss
DQ48
DQ49
DQ50
DQ51
Vdd
DQ52
NC
NC
REGE
Vss
DQ53
DQ54
DQ55
Vss
DQ56
DQ57
DQ58
DQ59
Vdd
DQ60
DQ61
DQ62
DQ63
Vss
CK3*
NC
SA0
SA1
SA2
Vdd
Description
The Enhanced Memory Systems 256MB, 512MB, and 1GB
low profile registered SDRAM DIMMs are ideal for high
memory capacity workstation and server applications. They
are offered in PC100 and PC133 speed grades and are
registered to minimize input loading for larger system
expansion. A phase lock loop (PLL) reduces clock loading
to minimize skew. The low profile (1.20 inch) products are
ideal for 1U rack mount systems.
The 256MB module is organized as 32Mx72, the 512MB
module is organized as 64Mx72, and the 1GB module is
organized as 128Mx72. Each module contains a serial
presence EEPROM, which contains information on the
module type, module organization, component speed, and
other attributes relevant to the system controller.
* Not used on these modules
Enhanced Memory Systems Inc., 1850 Ramtron Dr., Colo Spgs, CO 80921
PHONE: (800) 545-DRAM; FAX: (719) 488 -9095;
http://www.edram.com
Page 1
2001 Enhanced Memory Systems. All rights reserved.
The information cont ained herein is subject to change without notice.
Revision 1.1
RAMTRON [ RAMTRON INTERNATIONAL CORPORATION ]
