| |
SDR
|
DDR
|
DDR2 |
| Power supply |
3.3V
|
2.5V
|
1.8V |
| Applied clock |
~133MHz |
75M~200MHz |
125MHz~266(333)MHz |
| R/W data rate |
~133Mbps/pin |
150M~400Mbps/pin |
~553(667)Mbps/pin |
| I/O standard |
LVTTL |
SSTL2 |
SSTL18 |
On-chip DLL
|
× |
○ |
○ |
| Data strobe (DQS) |
× |
○ |
○ |
Data alignment
|
CLK edge on read |
DQS center on reads |
DQS center on reads |
| CLK edge on writes |
DQS edge on writes |
DQS edge on writes |
|