types of ROM

You can install multiple types of ROM on a computer or electronic device. The different ROM provides unique benefits to a user and can increase the functionality of a device's ROM. The types of ROM you may install on a device are:                      

                                                                   

      

1. ROM

The most basic form of ROM features cards you can't alter after their creation. The manufacturer sets the information the ROM chip conveys, which is permanent. Although this form of ROM is inflexible, it's often less expensive and remains a reliable option for information and processes that remain constant throughout the life cycle of its device.

                                    

2. Programmable ROM

Programmable ROM, or PROM, arrives ready to use with all its circuits activated. Using a specialized tool, you can burn out select circuits to program the chip. Because programming occurs by permanently burning out the circuits that aren't needed to convey information, you can't reprogram a PROM. This means you can customize the data on the chip only once. You can program it using many software types because it doesn't rely on the hard wiring of the program to the chip. You can use PROM in:

Mobile phones

Video game consoles

Medical devices

Radio Frequency Identification (RFID) tags

3. Mask ROM

Mask ROM, or MROM, is a type where the integrated circuit manufacturer programs the content instead of the user. It offers intellectual property protection by reserving the reproduction of the product to the manufacturer. The cost of integrated circuits depends on the size of the component. MROM has a small component, making it inexpensive compared to other types of memory. Examples of computer systems that use MROM chips can include network operating systems, server operating systems, laser printers and electronic musical instruments.

4. Erasable programmable ROM

Erasable programmable ROM, or EPROM, is a nonvolatile memory that can retain data without a power supply. It offers a solution for situations requiring you to change ROM chips' information. It's also cost-effective because it doesn't require external memory. As with a PROM, an EPROM requires specialized tools to program. EPROM presents an additional feature—the ability to erase the contents by projecting a UV light through a quartz window on the chip. Doing so resets the EPROM and allows you to reprogram from a blank chip to update information.

5. Electrically erasable programmable ROM

Electrically erasable programmable ROM, or EEPROM, is a modified version of EPROM that you alter using electrical signals instead of ultraviolet rays. It offers three important benefits that other options don't. The first benefit of EEPROM is the ability to change it without using specialized tools, making it a more accessible form of ROM.

Second, it's the only form of ROM you can update without entirely erasing the chip's contents. This means you can change your EEPROM chip without losing important information. Third, using electrical signals to erase and program data is time-efficient and can enable you to reprogram the data an infinite number of times without damaging it. The applications of EEPROM can include:

Debugging

Microcontrollers for smart cards

Remote keyless systems

BIOS chip in computers

Related: What Is Virtual Memory and How Does It Work?

6. Flash ROM

Flash ROM is nonvolatile RAM that's smaller, lighter and more energy efficient than a hard drive, and it's common mostly in portable devices. It's a utility for identifying, reading, writing, verifying and erasing flash chips. You can use flash ROM in personal digital assistants (PDAs), digital audio players, digital cameras, industrial robotics and medical electronics.