The DDR SDRAM is a high--speed CMOS, dynamic
random--access memory internally configured as a
quad--bank DRAM. These devices contain the following
number of bits:
64 Mb has 67,108,864 bits
128 Mb has 134,217,728 bits
256 Mb has 268,435,456 bits
512 Mb has 536,870,912 bits
1 Gb has 1,073,741,824 bits
...