Preliminary Data Sheet
168-pin Low Profile ESDRAM DIMMs
32MB, 64MB, 128MB
Features
•
•
JEDEC Standard 168-pin SDRAM DIMM
Low Latency 166 MHz Modules (2:2:2)
•
CAS Latency = 2
•
RAS to CAS Delay = 2
•
Precharge Delay = 2
Sustained Random Burst Reads (same bank access)
•
1-1-1-1 at 66MHz (CL = 1)
•
2-1-1-1 at 166MHz (CL = 2)
Early Auto-Precharge and Pipelined Row Activation
Hidden Auto-Refresh (4K, 64ms)
Fully Synchronous Operation
On-board Serial Presence Detect (SPD)
Unbuffered 168-pin DIMM
Single 3.3V
±
0.3V Power Supply
Low Profile for IU Rack Mount Systems
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
RFU
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
NC
Vss
DQ53
DQ54
DQ55
Vss
DQ56
DQ57
DQ58
DQ59
Vdd
DQ60
DQ61
DQ62
DQ63
Vss
CK3
NC
SA0
SA1
SA2
Vdd
•
•
•
•
•
•
•
•
Description
The Enhanced SDRAM (ESDRAM) DIMMs are low
latency, high performance memory modules of 32, 64, and
128 MByte capacities, and are organized x64 or x72 bits
wide. These DIMMs are 100% pin, function, and timing
compatible with JEDEC standard 168-pin SDRAM DIMMs.
The 32 MByte and 64 MByte DIMMs employ a single
physical bank of memory while the 128 MByte DIMMs are
built as two physical banks. Within each physical bank of
memory are four logical banks, which are accessed through
the use of BA0 and BA1 (pins 122 and 39). All control,
access, and data input signals are registered into each of the
ESDRAM components through use of an external clock,
CK0-CK3.
ESDRAM DIMMs provide pipeline burst SRAM
performance up to 66 MHz and nearly the same at bus
speeds up to 166 MHz. This performance is achieved using
JEDEC superset features including early auto-precharge and
pipelined row activation. The ESDRAM also supports
hidden auto-refresh.
All ESDRAM DIMMs operate from a 3.3V power supply,
and all inputs and outputs are LVTTL compatible. The
DIMM has a low 1.15-inch height to support IU rack mount
system requirements. See the ESDRAM component data
sheet for a more detailed discussion of ESDRAM
specifications and functional operation.
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.
Page 1 of 15
Revision 1.0
RAMTRON [ RAMTRON INTERNATIONAL CORPORATION ]
