Until 2.6.1.2

Questions and Answers

ROM

EPROM can be erased and reused by shining ultraviolet light on to the chip, while EEPROM can only be erased electrically

Flash memory can be erased and re-written electrically in circuit, while EPROM requires shining ultraviolet light or an electrical erase

Flash memory Signup and view all the answers

Static RAM retains information as long as power is applied, while dynamic RAM needs to be refreshed regularly Signup and view all the answers

PROM is programmed by the manufacturer, while ROM is programmed later in the field by a user Signup and view all the answers

RAM is volatile Signup and view all the answers

MOS capacitor Signup and view all the answers

Study Notes

Overview of Memory Devices and Their Types

RAM and ROM are two primary types of semiconductor memories.
RAM is volatile, and the data is lost when the power source is removed, but non-volatile RAMs exist.
ROM is non-volatile, and the logic function is stored permanently without electrical power.
EPROM or Erasable PROM can be erased and reused by shining ultraviolet light on to the chip.
PROM or Programmable ROM is not stored during manufacture, but later in the field by a user with necessary programming equipment.
EEPROM or E2PROM is a special type of erasable semiconductor memory where the data can be erased and re-written electrically in circuit.
Flash memory is a type of EEPROM that updates its contents in terms of groups of bytes or sectors.
NAND flash memory is commonly available as “memory cards” like Compact Flash (CF), Secure Digital (SD), MultiMedia Card (MMC) formats, etc.
RAM devices can be classified into two types: static and dynamic.
Static RAM's use a flip-flop as the storage element, and information is retained in the F/F for as long as power is applied.
Dynamic RAMs use the ability of MOS capacitors to store charge as the basic storage element, which must be refreshed regularly.
RAMs are manufactured using both MOS and bipolar technologies.