GENERAL DESCRIPTION
The W971GG6SB is a 1G bits DDR2 SDRAM, organized as 8,388,608 words x 8 banks x 16 bits. This device achieves high speed transfer rates up to 1066Mb/sec/pin (DDR2-1066) for various applications. W971GG6SB is sorted into the following grade parts: -18, 18I, -25, 25I and -3. The -18 and 18I grade parts are compliant to the DDR2-1066 (6-6-6) specification (the 18I industrial grade which is guaranteed to support -40°C ≤ TCASE ≤ 95°C). The -25 and 25I grade parts are compliant to the DDR2-800 (5-5-5) or DDR2-800 (6-6-6) specification (the 25I industrial grade which is guaranteed to support -40°C ≤ TCASE ≤ 95°C). The -3 grade parts is compliant to the DDR2-667 (5-5-5) specification.
All of the control and address inputs are synchronized with a pair of externally supplied differential clocks. Inputs are latched at the cross point of differential clocks (CLK rising and CLK falling). All I/Os are synchronized with a single ended DQS or differential DQS- DQS pair in a source synchronous fashion.

2. FEATURES
● Power Supply: VDD, VDDQ = 1.8 V ± 0.1 V
● Double Data Rate architecture: two data transfers per clock cycle
● CAS Latency: 3, 4, 5, 6 and 7
● Burst Length: 4 and 8
● Bi-directional, differential data strobes (DQS and DQS ) are transmitted / received with data
● Edge-aligned with Read data and center-aligned with Write data
● DLL aligns DQ and DQS transitions with clock
● Differential clock inputs (CLK and CLK )
● Data masks (DM) for write data
● Commands entered on each positive CLK edge, data and data mask are referenced to both edges of DQS
● Posted CAS programmable additive latency supported to make command and data bus efficiency
● Read Latency = Additive Latency plus CAS Latency (RL = AL + CL)
● Off-Chip-Driver impedance adjustment (OCD) and On-Die-Termination (ODT) for better signal quality
● Auto-precharge operation for read and write bursts
● Auto Refresh and Self Refresh modes
● Precharged Power Down and Active Power Down
● Write Data Mask
● Write Latency = Read Latency - 1 (WL = RL - 1)
● Interface: SSTL_18
● Packaged in WBGA 84 Ball (8x12.5 mm2), using Lead free materials with RoHS compliant