DDR SDRAM is similar in function to the regular SDRAM but doubles the
bandwidth of the memory by transferring data on both edges of the clock cycles.
DDR SDRAM most commonly used in various embedded application like networking,
image or video processing, Laptops ete. Now a days many applications needs more
and more cheap and fast memory. Especially in the field of signal processing,
requires significant amount of memory. The most used type of dynamic memory for
that purpose is DDR SDRAM.