DDR

1) DDR1/DDR2/DDR3
2) 168/184/240-pin socket type dual in line memory module (DIMM)
3) ram for desktop,ram for laptop
4) Data rate: 533/667/800Mbps (max.)
5) 2.5 V (SSTL-2 compatible) I/O for DDR I products,1.8Vpower supply for DDR II products
6) Double-data-rate architecture, two data transfers per clock cycle
7) Bi-directional, differential data strobe (DQS) is transmitted/received with data, to be used in capturing data at the receiver
8) Data inputs and outputs are synchronized with DQS
9) DQS is edge aligned with data for read, center aligned with data for write
10) Differential clock inputs (CK and CK)
11) DLL aligns DQ and DQS transitions with CK transitions
12) Commands entered on each positive CK edge: data and data mask referenced to both edges of DQS
13) Four internal banks for concurrent operation (component)
14) Data mask(DM) for write data
15) Auto precharge option for each burst access
16) Programmable burst length: 2, 4, 8
17) Programmable/CAS latency (CL): 3
18) Programmable output driver strength: normal/weak
19) Refresh cycles: (8192 refresh cycles/64ms)
20) 7.8US maximum average periodic refresh interval
21) Posted CAS by programmable additive latency for better command and data bus efficiency
22) Off-chip-driver impedance adjustment and on-die-termination for better signal quality
23) DQS can be disabled for single-ended data strobe operation
24) 2 variations of refresh
25) Auto refresh
26) Self refresh