Winbond, W9425G6KH-5I

The W9425G6KH is a 256M DDR SDRAM and speed involving -4/-5/-5I/-5A.

Up to 250 MHz Clock Frequency
Double Data Rate architecture, two data transfers per clock cycle
Differential clock inputs (CLK and /CLK)
DQS is edge-aligned with data for Read, center-aligned with data for Write
CAS Latency: 2, 2.5, and 3
Burst Length: 2, 4 and 8
Auto Refresh and Self Refresh
Precharged Power Down and Active Power Down
Write Data Mask
Write Latency = 1
7.8μS refresh interval (8K/64 mS refresh)
Maximum burst refresh cycle: 8
Interface: SSTL_2