SIMM單邊接觸內(nèi)存模組。是5X86及其較早的PC中常采用的內(nèi)存接口方式。在486以前，多采用30針的SIMM接口，而在Pentuim中更多的是72針的SIMM接口，或者與DIMM接口類型并存。人們通常把72線的SIMM類型內(nèi)存模組直接稱為72線內(nèi)存條。
SIMM 是 Single Inline Memory Module (單列直插) 的縮寫，72 線內(nèi)存條的外觀為：
|
SIMM ECC 72線內(nèi)存條引腳定義 |
|
Pin |
無校驗 |
有校驗 |
Description |
|---|---|---|---|
|
1 |
VSS |
VSS |
Ground |
|
2 |
DQ0 |
DQ0 |
Data 0 |
|
3 |
DQ16 |
DQ16 |
Data 16 |
|
4 |
DQ1 |
DQ1 |
Data 1 |
|
5 |
DQ17 |
DQ17 |
Data 17 |
|
6 |
DQ2 |
DQ2 |
Data 2 |
|
7 |
DQ18 |
DQ18 |
Data 18 |
|
8 |
DQ3 |
DQ3 |
Data 3 |
|
9 |
DQ19 |
DQ19 |
Data 19 |
|
10 |
VCC |
VCC |
+5 VDC |
|
11 |
n/c |
n/c |
Not connected |
|
12 |
A0 |
A0 |
Address 0 |
|
13 |
A1 |
A1 |
Address 1 |
|
14 |
A2 |
A2 |
Address 2 |
|
15 |
A3 |
A3 |
Address 3 |
|
16 |
A4 |
A4 |
Address 4 |
|
17 |
A5 |
A5 |
Address 5 |
|
18 |
A6 |
A6 |
Address 6 |
|
19 |
A10 |
A10 |
Address 10 |
|
20 |
DQ4 |
DQ4 |
Data 4 |
|
21 |
DQ20 |
DQ20 |
Data 20 |
|
22 |
DQ5 |
DQ5 |
Data 5 |
|
23 |
DQ21 |
DQ21 |
Data 21 |
|
24 |
DQ6 |
DQ6 |
Data 6 |
|
25 |
DQ22 |
DQ22 |
Data 22 |
|
26 |
DQ7 |
DQ7 |
Data 7 |
|
27 |
DQ23 |
DQ23 |
Data 23 |
|
28 |
A7 |
A7 |
Address 7 |
|
29 |
A11 |
A11 |
Address 11 |
|
30 |
VCC |
VCC |
+5 VDC |
|
31 |
A8 |
A8 |
Address 8 |
|
32 |
A9 |
A9 |
Address 9 |
|
33 |
/RAS3 |
/RAS3 |
Row Address Strobe 3 |
|
34 |
/RAS2 |
/RAS2 |
Row Address Strobe 2 |
|
35 |
n/c |
PQ3 |
Parity bit 3 (for the 3rd byte, bits 16-23) |
|
36 |
n/c |
PQ1 |
Parity bit 1 (for the 1st byte, bits 0-7) |
|
37 |
n/c |
PQ2 |
Parity bit 2 (for the 2nd byte, bits 8-15) |
|
38 |
n/c |
PQ4 |
Parity bit 4 (for the 4th byte, bits 24-31) |
|
39 |
VSS |
VSS |
Ground |
|
40 |
/CAS0 |
/CAS0 |
Column Address Strobe 0 |
|
41 |
/CAS2 |
/CAS2 |
Column Address Strobe 2 |
|
42 |
/CAS3 |
/CAS3 |
Column Address Strobe 3 |
|
43 |
/CAS1 |
/CAS1 |
Column Address Strobe 1 |
|
44 |
/RAS0 |
/RAS0 |
Row Address Strobe 0 |
|
45 |
/RAS1 |
/RAS1 |
Row Address Strobe 1 |
|
46 |
n/c |
n/c |
Not connected |
|
47 |
/WE |
/WE |
Read/Write |
|
48 |
n/c |
n/c |
Not connected |
|
49 |
DQ8 |
DQ8 |
Data 8 |
|
50 |
DQ24 |
DQ24 |
Data 24 |
|
51 |
DQ9 |
DQ9 |
Data 9 |
|
52 |
DQ25 |
DQ25 |
Data 25 |
|
53 |
DQ10 |
DQ10 |
Data 10 |
|
54 |
DQ26 |
DQ26 |
Data 26 |
|
55 |
DQ11 |
DQ11 |
Data 11 |
|
56 |
DQ27 |
DQ27 |
Data 27 |
|
57 |
DQ12 |
DQ12 |
Data 12 |
|
58 |
DQ28 |
DQ28 |
Data 28 |
|
59 |
VCC |
VCC |
+5 VDC |
|
60 |
DQ29 |
DQ29 |
Data 29 |
|
61 |
DQ13 |
DQ13 |
Data 13 |
|
62 |
DQ30 |
DQ30 |
Data 30 |
|
63 |
DQ14 |
DQ14 |
Data 14 |
|
64 |
DQ31 |
DQ31 |
Data 31 |
|
65 |
DQ16 |
DQ16 |
Data 16 |
|
66 |
n/c |
n/c |
Not connected |
|
67 |
PD1 |
PD1 |
Presence Detect 1 |
|
68 |
PD2 |
PD2 |
Presence Detect 2 |
|
69 |
PD3 |
PD3 |
Presence Detect 3 |
|
70 |
PD4 |
PD4 |
Presence Detect 4 |
|
71 |
n/c |
n/c |
Not connected |
|
72 |
VSS |
VSS |
Ground |
容量定義：
|
PD2 |
PD1 |
容量 |
|---|---|---|
|
GND |
GND |
4 or 64 MB |
|
GND |
NC |
2 or 32 MB |
|
NC |
GND |
1 or 16 MB |
|
NC |
NC |
8 MB |
存取速度：
|
PD4 |
PD3 |
速度 |
|---|---|---|
|
GND |
GND |
50, 100 ns |
|
GND |
NC |
80 ns |
|
NC |
GND |
70 ns |
|
NC |
NC |
60 ns |