168-pin Enhanced SDRAM DIMM
8MB, 16MB, 32MB DIMM
Preliminary Data Sheet
Pin Assignments
Features
Pin
Symbol
Pin
Symbol
Pin
Symbol
Pin
Symbol
•
•
•
•
•
•
JEDEC Standard 168-pin SDRAM DIMM
PC-100 Spec Compliant – Lowest Latency
Single 3.3V ± 0.3V Power Supply
Unbuffered
Fully Synchronous Operation
Sustained Random Burst Reads (Same Bank Access)
1
Vss
DQ0
DQ1
DQ2
DQ3
Vdd
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
Vss
DU
85
86
Vss
DQ32
DQ33
DQ34
DQ35
Vdd
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
Vss
CKE0
S3#
2
3
S2#
87
4
DQMB2
DQMB3
DU
88
DQMB6
DQMB7
RFU
Vdd
5
89
6
90
•
•
1-1-1-1 at 66MHz (CL=1)
2-1-1-1 at 133MHz (CL=2)
7
DQ4
DQ5
DQ6
DQ7
DQ8
Vss
Vdd
91
DQ36
DQ37
DQ38
DQ39
DQ40
Vss
8
NC
92
NC
•
•
•
•
•
Programmable Burst Lengths: 1, 2, 4, 8, or Full page
Early Auto-Precharge and Auto-Refresh Modes
64ms, 2048 Cycle Refresh
LVTTL Compatible Inputs and I/Os
On-Board Serial Presence Detect (SPD) EEPROM with
Write Protect Input
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
NC
94
NC
NC
95
NC
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
Description
99
The Enhanced SDRAM (ESDRAM) DIMMs are low
latency, high performance memory modules of 8, 16, and 32
MByte capacities, and are organized x64 bits wide. The
DIMMs are 100% pin, function, and timing compatible with
JEDEC standard 168-pin SDRAM DIMMs. The 8MB and
16MB DIMMs employ a single physical bank of memory
while the 32MB DIMMs are built as two physical banks.
Within each physical bank of memory are two logical banks,
which are accessed through the use of BA0 (pin 122). All
control, access, and data input signals are registered into
each of the ESDRAM components through use of an
external clock, CK0-CK3. The rising edge of the clock is
used as the timing reference for all inputs and outputs.
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
NC
DQ46
DQ47
NC
NC
NC
CKE1
Vss
NC
NC
NC
Vss
Vss
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
ESDRAM DIMMs provide pipelined burst SRAM
performance up to 66MHz and nearly the same at bus speeds
up to 133MHz. The speed grade of each DIMM is specified
to real system operation. No de-rating is necessary. For
example, the 10ns DIMM operates at 100MHz in CL=2
mode, and the 7.5ns DIMM operates at 66MHz in CL=1
mode and up to 133MHZ in CL=2 mode.
DU
RAS#
Vss
Vss
DQ28
DQ29
DQ30
DQ31
Vss
DQ60
DQ61
DQ62
DQ63
Vss
A0
A1
All ESDRAM DIMMs operate from a 3.3V power supply,
and all inputs and outputs are LVTTL compatible. See the
ESDRAM component data sheet for a more detailed
discussion of ESDRAM specifications and functional
operation.
A2
A3
A4
A5
A6
A7
A8
CK2
A9
CK3
A10/AP
RFU
Vdd
NC
BA0
NC
WP
RFU
Vdd
SA0
SDA
SCL
SA1
Vdd
CK1
SA2
CK0
Vdd
RFU
Vdd
Enhanced Memory Systems Inc., 1850 Ramtron Dr., Colo Spgs, CO 80921
PHONE: (800) 545-DRAM; FAX: (719) 488-9095; http://www.edram.com
1999 Enhanced Memory Systems. All rights reserved.
The information contained herein is subject to change without notice.
Revision 3.1
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