168-pin Low Profile SDRAM DIMMs
32MB, 64MB, 128MB, 256MB, 512MB
Data Sheet
Serial Presence Detect (SPD) for SDRAM DIMMs
256MB
512MB
256MB
512MB
Byte Description
** Hex Code **
0
1
2
3
4
5
6
Number of bytes written into EEPROM
Total number of SPD bytes
Memory Type
Number of Row Addresses
Number of Column Addresses
Number of Module Banks
128
256
SDRAM
12
10
2
x64
x72
128
256
SDRAM
13
10
2
x64
x72
0
80
08
04
0C
0A
02
40
48
00
01
75
54
00
02
80
08
00
08
01
8F
04
06
01
01
00
07
A0
60
00
00
14
14
14
2D
20
15
08
15
08
00
12
AE
C0
80
08
04
0D
0A
02
40
48
00
01
75
54
00
02
82
08
00
08
01
8F
04
06
01
01
00
07
A0
60
00
00
14
14
14
2D
40
15
08
15
08
00
12
D1
E3
Module Data Width
x64
x72
7
8
Module Data Width (cont'd)
Voltage Interface Levels
0
LVTTL
7.5 ns
5.4 ns
LVTTL
7.5 ns
5.4 ns
9
10
11
Cycle Time at max CAS Latency
SDRAM Clock Access Time
DIMM config (non-parity, parity, ECC)
--- Non-parity ---
--- ECC ---
--- 15.625us / Self ---
12
13
14
Refresh Rate and Type
Primary SDRAM Width
Error Checking Data Width
7.8 us
x8
N/A
x8
x8
N/A
x8
x64
x72
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
Min. CAS-to-CAS Delay (tCCD)
Burst Lengths Supported
Number of Banks on SDRAM Device
CAS Latencies Supported
CS Latency
1 clk
1 clk
--- 1,2,4,8,Full Pg ---
4
2,3
0
4
2,3
0
Write Latency
0
0
SDRAM Module Attributes
SDRAM Device Attributes
Min. Clock Cycle Time at CL=2
Clock Access Time at CL=2 (tAC2)
Min. Clock Cycle Time at CL=1
Clock Access Time at CL=1 (tAC1)
Min. Row Precharge Time (tRP)
Min. Row-to-Row Delay (tRRD)
Min. RAS-to-CAS Delay (tRCD)
Min. RAS Pulse Width (tRAS)
Density of each bank on module
Cmd/Addr input set-up time
Cmd/Addr input hold time
Data input set-up time
--- Unbuffered ---
+/-10% Vdd, Precharge All
10 ns
6.0 ns
N/A
10 ns
6.0 ns
N/A
N/A
N/A
20 ns
20 ns
20 ns
45 ns
128 MB
20 ns
20 ns
20 ns
45 ns
256 MB
1.5 ns
0.8 ns
1.5 ns
0.8 ns
Data input hold time
36-61 Superset Information
-
-
-
-
62
63
SPD Rev.
Checksum for bytes 0-62
1.2
x64
x72
64-71 JEDEC ID code
Enhanced Memory Systems
7F32FFFFFFFFFFFF
72
Manufacturing Location
-
-
xxxx
xxxx
xxxx
rrrr
xxxx
xxxx
xxxx
rrrr
73-90 Manufacturer's Part #
x64
x72
SM25608ALDT
SM25609ALDT
SM51208BLDT
SM51209BLDT
91,92 PCB Rev. Code
-
93,94 Manufacturing Date
95-98 Assembly Serial #
99-125 Manufacturer's Specific Data
126 Intel specification frequency
yyww code
serial number
open
yyww
ssss
00
yyww
ssss
00
100MHz
64
64
127 Intel specification CL and clock support
128-255 Open for Customer Use
-
-
-
-
AF
00
FF
00
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.
Revision 1.1
Page 17 of 20
RAMTRON [ RAMTRON INTERNATIONAL CORPORATION ]
