Description
ISSI's 512Mb DDR2 SDRAM uses a double-data-rate architecture to achieve high-speed operation.
The double-data rate architecture is essentially a 4n-prefetch architecture, with an interface designed to transfer two data words per clock cycle at the I/O balls.
Features
- Vdd = 1.8V ±0.1V, Vddq = 1.8V ±0.1V.
- JEDEC standard 1.8V I/O (SSTL_18-compatible).
- Double data rate interface: two data transfers
per clock cycle.
- Differential data strobe (DQS, DQS).
- 4-bit prefetch architecture.
- On chip DLL to align DQ and DQS transitions
with CK.
- 4 internal banks for concurrent operation.
- Programmable CAS latency (CL) 3, 4, 5, and 6
supported.
- Posted CAS and programmable additive latency
(AL) 0,.