Allwinner A64 Single Board Computer Project

[ThreeNamesGrace]

Hello, I am doing a Single Board Computer with Allwinner A64 CPU chip and with the K4B4G1646D DDR3 RAM memory modules. I chose those components because they are really cheap and their shipping to my country is really inexpensive. So far, I uploaded the symbols and their footprints to Kicad, now I am wiring the RAM memory to the CPU, but I found some issues that I couldn't figure out how to deal with them:

• There are 15 pins for the address bus in the memory chip, while there are 16 pins on the CPU.
• There are 32 pins in the CPU for reading and writing data to the memory, but the memory only has 16, how do I know the order in which I should wire the pins?
  
• 2 chip selects in CPU (I plan to use 6 RAM chips to have 3 GBytes of space, as that is the maximum stated in the datasheet); should I look for another brand of memory modules? Use a SODIMM memory chip for laptops instead? Or look for another CPU?

As far as I researched, in the CPU user manual is mentioned "32-bit DDR2" and "16-bit DDR3", but neither the user manual nor the datasheet mention what is the bit order for 16-bit DDR3.