DDR SDRAM DIMM 184 Pin

Your support helps keep this website running. Please consider supporting this project. SPONSOR DONATE

01 Jan 2000

Updated: 29 Jun 2026

184-pin DDR SDRAM DIMM

The 184-pin DDR SDRAM DIMM is the JEDEC-standardised desktop memory module used for first-generation DDR (“DDR1”) memory, replacing the earlier 168-pin SDR SDRAM DIMM. DDR doubles the bandwidth of plain SDRAM by transferring data on both the rising and falling edges of the clock. The module carries a 64-bit data bus (72-bit on ECC versions) and uses 2.5 V SSTL_2 signalling, compared with 3.3 V for the older SDR modules. Common speed grades are PC1600 (DDR-200), PC2100 (DDR-266), PC2700 (DDR-333) and PC3200 (DDR-400).

DIMM: Dual Inline Memory Module
SDRAM: Synchronous Dynamic Random Access Memory, synchronous to the positive clock edge
DDR: Double Data Rate

A 184-pin DDR DIMM has a single key notch in the contact edge — unlike the 168-pin SDR SDRAM DIMM, which has two — plus a retention cut-out at each end for the socket latches. The key notch is offset from the centre of the module so the DIMM cannot be inserted backwards. Its position relative to the centreline (to the left of, centred on, or to the right of the gap between pins 52 and 53) encodes the module’s I/O voltage class and prevents installing the wrong type into a socket, which could otherwise damage the DIMM.

PIN CONFIGURATIONS (Front side / back side)

PIN	FRONT	PIN	FRONT	PIN	FRONT	PIN	BACK	PIN	BACK	PIN	BACK
1	VREF	32	A5	62	VDD	93	VSS	124	VSS	154	RAS#
2	DQ0	33	DQ24	63	WE#	94	DQ4	125	A6	155	DQ45
3	VSS	34	VSS	64	DQ41	95	DQ5	126	DQ28	156	VDD
4	DQ1	35	DQ25	65	CAS#	96	VDD	127	DQ29	157	S0#
5	DQS0	36	DQS3	66	VSS	97	DQS9	128	VDD	158	S1#
6	DQ2	37	A4	67	DQS5	98	DQ6	129	DQS12	159	DQS14
7	VDD	38	VDD	68	DQ42	99	DQ7	130	A3	160	VSS
8	DQ3	39	DQ26	69	DQ43	100	VSS	131	DQ30	161	DQ46
9	NC	40	DQ27	70	VDD	101	NC	132	VSS	162	DQ47
10	NC	41	A2	71	NC	102	NC	133	DQ31	163	NC
11	VSS	42	VSS	72	DQ48	103	NC	134	CB4	164	VDD
12	DQ8	43	A1	73	DQ49	104	VDD	135	CB5	165	DQ52
13	DQ9	44	CB0	74	VSS	105	DQ12	136	VDD	166	DQ53
14	DQS1	45	CB1	75	CK2#	106	DQ13	137	CK0	167	NC
15	VDD	46	VDD	76	CK2	107	DQS10	138	CKO#	168	VDD
16	CK	47	DQS8	77	VDD	108	VDD	139	VSS	169	DQS15
17	CK1#	48	A0	78	DQS6	109	DQ14	140	DQS17	170	DQ54
18	VSS	49	CB2	79	DQ50	110	DQ15	141	A10	171	DQ55
19	DQ10	50	VSS	80	DQ51	111	CKE1	142	CB6	172	VDD
20	DQ11	51	CB3	81	VSS	112	VDD	143	VDD	173	NC
21	CKE0	52	BA1	82	NC	113	NC	144	CB7	174	DQ60
22	VDD		KEY	83	DQ56	114	DQ20		KEY	175	DQ61
23	DQ16	53	DQ32	84	DQ57	115	A12	145	VSS	176	VSS
24	DQ17	54	VDD	85	VDD	116	VSS	146	DQ36	177	DQS16
25	DQS2	55	DQ33	86	DQS7	117	DQ21	147	DQ37	178	DQ62
26	VSS	56	DQS4	87	DQ58	118	A11	148	VDD	179	DQ63
27	A9	57	DQ34	88	DQ59	119	DQS11	149	DQS13	180	VDD
28	DQ18	58	VSS	89	VSS	120	VDD	150	DQ38	181	SA0
29	A7	59	BA0	90	NC	121	DQ22	151	DQ39	182	SA1
30	VDD	60	DQ35	91	SDA	122	A8	152	VSS	183	SA2
31	DQ19	61	DQ40	92	SCL	123	DQ23	153	DQ44	184	VDDSPD

PIN DESCRIPTION

PIN	NAME FUNCTION
A0-A11	Address input (Multiplexed)
BA0~BA1	Bank Select Address
DQ0~Q63	Data input/output
DQ0~DQS7	Data Strobe input/output
CK0, CK0#, CK1, CK1#, CK2, CK2#	Clock input
CKE0, CKE1	Clock enable input
S0#, S1#	Chip select input
RAS	Row address strobe
CAS	Column address strobe
WE	Write enable
WP	Write protect
VDD	Power supply (2.5v)
VDDQ	Power supply for DQS (2.5V)
VSS	Ground
VREF	Power supply for reference
VDDSPD	Serial EEPROM Power Supply (2.3V to 3.6V)
SDA	Serial data I/O
SCL	Serial Clock
SA0-SA2	Address in EEPROM
VDDID	VDD identification flag
NC	No connection

References

Category:Memory Connectors