168 Pin Registered SDRAM DIMM (Buffered) Pinout

Personal Computer Memory Module description, 168-pin Buffered SDRAM DIMM Pin out.
The 168-pin DIMM have 84 pins per PWB side. Buffered implies driving more than one load.
The Front Side board pinout contains left side pins 1-42, and right side pins 43-84.
The Back Side board pin-out has left side pins 85-126, and right side pins 127-168.
168-pin DIMM memory modules would be found in Desktop computers.

Front, Left Side Signals

**168-Pin Registered SDRAM DIMM PinOut**
Pin #	Pin name	Pin Description
1	VSS	Ground
2	DQ0	Data 0
3	DQ1	Data 1
4	DQ2	Data 2
5	DQ3	Data 3
6	VCC	+5 VDC or +3.3 VDC
7	DQ4	Data 4
8	DQ5	Data 5
9	DQ6	Data 6
10	DQ7	Data 7
11	DQ8	Data 8
12	VSS	Ground
13	DQ9	Data 9
14	DQ10	Data 10
15	DQ11	Data 11
16	DQ12	Data 12
17	DQ13	Data 13
18	VCC	+5 VDC or +3.3 VDC
19	DQ14	Data 14
20	DQ15	Data 15
21	CB0	Parity/Check Bit Input/Output 0
22	CB1	Parity/Check Bit Input/Output 1
23	VSS	Ground
24	NC	No Connection
25	NC	No Connection
26	VCC	+5 VDC or +3.3 VDC
27	/WE0	Read/Write Input
28	/CAS0	Column Address Strobe 0
29	/CAS1	Column Address Strobe 1
30	/RAS0	Row Address Strobe 0
31	NC	No Connection
32	VSS	Ground
33	A0	Address 0
34	A2	Address 2
35	A4	Address 4
36	A6	Address 6
37	A8	Address 8
38	A10/AP	Address 10
39	BA1	-
40	VCC	+5 VDC or +3.3 VDC
41	VCC	+5 VDC or +3.3 VDC
42	CK0	-

Front, Right Side Signals

**168-Pin SDRAM DIMM PinOut**
Pin #	Pin name	Pin Description
43	VSS	Ground
44	NC	No Connection
45	/RAS2	Row Address Strobe 2
46	/CAS2	Column Address Strobe 2
47	/CAS3	Column Address Strobe 3
48	NC	No Connection
49	VCC	+5 VDC or +3.3 VDC
50	NC	No Connection
51	NC	No Connection
52	CB2	Parity/Check Bit Input/Output 2
53	CB3	Parity/Check Bit Input/Output 3
54	VSS	Ground
55	DQ16	Data 16
56	DQ17	Data 17
57	DQ18	Data 18
58	DQ19	Data 19
59	VCC	+5 VDC or +3.3 VDC
60	DQ20	Data 20
61	NC	Not connected
62	NC	No Connection
63	CKE1	-
64	VSS	Ground
65	DQ21	Data 21
66	DQ22	Data 22
67	DQ23	Data 23
68	VSS	Ground
69	DQ24	Data 24
70	DQ25	Data 25
71	DQ26	Data 26
72	DQ27	Data 27
73	VCC	+5 VDC or +3.3 VDC
74	DQ28	Data 28
75	DQ29	Data 29
76	DQ30	Data 30
77	DQ31	Data 31
78	VSS	Ground
79	CK2	-
80	NC	Not connected
81	WP	-
82	SDA	Serial Data
83	SCL	Serial Clock
84	VCC	+5 VDC or +3.3 VDC

Back, Left Side Signals

Rear-Side 168-pin Buffered Pin Out

Data width is 64 bits per memory stick [the front side 84 pins are not connected together with the back side 84 pins]

The approximate board size. 5.375" x 1.375"

DRAM: Dynamic Random Access Memory
SO DIMM: Small Outline Dual Inline Memory Module [Lap-top & Note-book memory]
SDRAM:: Synchronous DRAM (Random Access Memory), Synchronous to Positive Clock Edge.
All 168 pin DIMMs use either 66MHz SDRAM, PC100 SDRAM, PC133 SDRAM, EDO or FPM memory.
168 pin DIMMs have two alignment notches as shown.
The left most notch [keyway] determines the DRAM type. If the notch is centered then the memory module is Buffered DRAM [EDO or Fast Page].
If the notch is off-set to the rigth then the memory module is either a un-buffered DRAM/SDRAM DIMM or a buffered SDRAM DIMM.
The center notch determines the voltage. If the notch is centered then the DIMM operates off 3.3 volts.

Back to the main Computer Memory Modules information page. For electronic device manufacturers see one of these pages:
Memory IC manufacturers
Memory Module manufacturers
Memory Module Acronyms
IC Memory Acronyms
Additional electronic Equipment manufacturers may be found by selecting the OEM Equipment icon below.
Component manufacturers may be found by selecting the Components icon below.

Note 168 pin DIMMs are out-dated, over taken by the DDR series of DIMMs [refer to the memory module link just above].
So this style DIMM is found on older PC motherboards, but my still be purchased in 128MB, 256MB, or 512MB memory sticks.

Navigation: Engineering Home > OEM Equipment Vendors > Computer Gear > Memory Modules > Memory Module Pinout > 168 pin DIMM memory stick.


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