Memory Types

VOLATILE Group (No Memory retension when power is removed from the Memory Device)

STATIC RAM - This type of memory device is composed of registers. A byte of data is composed of 8 bits of binary information. If we consider a D-Type of register, a register is composed of flip-flops. Flip-flops are composed of Logic gates and Logic Gates are composed of Transistors. SRAMs are composed of transistors, making it very much expensive.

Dynamic RAM - This type of memory device is composed of capacitors as the memory element. Since capacitors can retain voltages, a refresh signal is needed to put the charge level of each capacitors in the DRAM in its proper value. Refreshing of data is done through RAS and CAS pins. The only disadvantage is that the DRAM cannot permit reading and writing data during its refresh state. DRAM is cheaper in comparison with the SRAM technology.

NON-Volatile Group (There is memory retension even if Power Supply is removed)

EPROM - This type of memory device is used for reading programs. An Ultra-voilet lamp is needed to erase the program inside the Memory device

EEPROM - This memory devices does not need Ultraviolet Lamps to erase the program inside the chip.