How to write data in RAM memory using Arduino Uno or Arduino Due? I know that it is possible to write data in ROM(Read Only Memory).
But what about if I want to write data in RAM(Random Access Memory)?
Can I do it using "Arduino Uno R3"?
RAM is normally associated with volatile types of memory.

There are several examples about writing data in EEPROM as in a (Read Only Memory) which may have 8 pins.
In order to store values read from analog input 0 into the EEPROM we need to use the "EEPROM.write()" function.
These values will stay in the EEPROM when the board is turned off and may be retrieved later by another sketch.
ROM is a Non-volatile type memory.
SD card is also Non-volatile type of memory.
We know that there are few SD card shields for "Arduino Uno" and it is possible create your own shields.       

But what about volatile types of memory?
what about if I want to write data in RAM like a "DDR SDRAM" or in a DDR3 memory which may have 240 pins instead of 8 pins?
So my question is is it possible to write data in "DDR SDRAM" using "Arduiono Uno R3"?
How? Where should I connect those 240 pins?
DRAM of any kind requires a memory controller which is not present in any AVR device. Larger AVR devices such as the ATmega64A and ATmega128A do have an external memory bus that can be used for SRAM and MMIO.