168-pin Low Profile Registered SDRAM DIMMs
256MB, 512MB, 1GB
Preliminary Data Sheet
Features
Pin Symbol
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
Pin
85
Symbol
Vss
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
·
·
·
·
·
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
1
Vss
DQ0
DQ1
DQ2
DQ3
Vdd
2
DNU
S2#
86
DQ32
DQ33
DQ34
DQ35
Vdd
CKE0
S3#
3
87
4
DQMB2
DQMB3
DNU
Vdd
88
DQMB6
DQMB7
RFU
5
89
6
90
·
·
·
Supports CAS Latency = 2, 3
On-board Serial Presence Detect (SPD)
Single 3.3V ± 0.3V Power Supply
7
DQ4
DQ5
DQ6
DQ7
DQ8
Vss
91
DQ36
DQ37
DQ38
DQ39
DQ40
Vss
Vdd
8
NC
92
NC
9
NC
93
NC
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
CB2
94
CB6
Description
CB3
95
CB7
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.
Vss
96
Vss
DQ9
DQ10
DQ11
DQ12
DQ13
Vdd
DQ16
DQ17
DQ18
DQ19
Vdd
97
DQ41
DQ42
DQ43
DQ44
DQ45
Vdd
DQ48
DQ49
DQ50
DQ51
Vdd
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
DQ20
NC
DQ52
NC
DQ14
DQ15
CB0
CB1
Vss
DQ46
DQ47
CB4
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.
NC
NC
CKE1*
Vss
REGE
Vss
CB5
DQ21
DQ22
DQ23
Vss
Vss
DQ53
DQ54
DQ55
Vss
NC
NC
NC
NC
Vdd
Vdd
WE#
DQMB0
DQMB1
S0#
DQ24
DQ25
DQ26
DQ27
Vdd
CAS#
DQMB4
DQMB5
S1#
DQ56
DQ57
DQ58
DQ59
Vdd
DNU
Vss
RAS#
Vss
DQ28
DQ29
DQ30
DQ31
Vss
DQ60
DQ61
DQ62
DQ63
Vss
A0
A1
A2
A3
A4
A5
A6
A7
A8
CK2*
NC
A9
CK3*
NC
A10/AP
BA1
Vdd
BA0
A11
WP
SA0
SDA
Vdd
SA1
Vdd
SCL
CK1*
A12
SA2
CK0
Vdd
Vdd
* 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
2001 Enhanced Memory Systems. All rights reserved.
The information contained herein is subject to change without notice.
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Revision 1.1