There is two types of internal memory. Name and discuss them
Answers
Answer:
The two types of internal memory are RAM (Random Access Memory) and ROM (Read Only Memory)
Explanation:
RAM (Random Access Memory)
Random access memory, or RAM, is memory storage on a computer that holds data while the computer is running so that it can be accessed quickly by the processor. RAM holds the operating system, application programs and data that is currently being used.
RAM data is much faster to read than data stored on the hard disk. RAM is stored in microchips and contains much less data than the hard disk. RAM can never run out of memory, but the processor must overwrite old data if the RAM is filled, which results in slower computer function. Any file stored in RAM can be accessed directly if the user knows the row and column where the data is stored.
Random access memory is used to store temporary but necessary information on a computer for quick access by open programs or applications.
RAM, is a volatile yet fast type of memory used in computers. RAM is more expensive to incorporate.
RAM allows reading and writing (electrically) of data at the byte level
RAM is the Volatile memory.
Types of RAM
Static RAM
Dynamic RAM
Static RAM
Static RAM stores a bit of information in a flip-flop. Static RAM is usually used for applications that do not require large capacity RAM memory.
Static(RAM) is a memory technology based on flip-flops. SRAM has an access time of 2 – 10 nanoseconds. All of main memory can be viewed as fabricated from SRAM, although such a memory would be unrealistically expensive.
Dynamic RAM
Dynamic RAM data store one bit of information as a payload. Dynamic RAM using a substrate capacitance gate MOS transistors as memory cells shut. To keep dynamic RAM stored data remains intact, the data should be refreshed again by reading and re-write the data into memory. Dynamic RAM is used for applications that require large RAM capacity, for example in a personal computer (PC)
EDO (Extended Data-output) and SD (Synchronous Dynamic Random Access Memory) are type of Dynamic RAM.
Dynamic RAM (DRAM) is a memory technology based on capacitors
Dynamic RAM is cheaper than static RAM and can be packed more densely on a computer chip
DRAM has an access time in the order of 60 – 100 nanoseconds, slower than SRAM.
ROM (Read only Memory)
Sometimes can be erased for reprogramming, but might have odd requirements such as UV light or erasure only at the block level
Sometimes require special device to program, i.e., processor can only read, not write.
Data are written into a ROM when it is manufactured.
ROM is mask programmed by the manufacturer in the factory with the contents ordered by the customers.
The contents are fixed by metal masks used during chip fabrication.
Once programmed, the contents cannot be erased.
Even a single bit wrongly programmed the ROM chip is useless
Types Of Internal Memory
Application
Used to store control programs such as micro program.
Character generation, code conversion
Permanent storage – nonvolatile
Microprogramming
Library subroutines
Systems programs (BIOS)
Function tables
Embedded system code
Types of ROM
PROM (Programmable Read Only Memory)
EPROM (Erasable Programmable Read Only Memory )
EEPROM (Electrically Erasable Programable Read Only Memory)
If the content is determined by the vendor ROM, PROM sold empty and can then be filled with a program by the user. Having completed the program, fill PROM cannot be removed.
PROM (Programmable Read Only Memory)
PROM is a field programmable device.
The customer buy a blank PROM and store desired data using PROM programmer(burner).
Programmability achieved by inserting a fuse at point P.
Before programmed, the memory contains all 0s
The user can insert 1 by burning out the fuse in the particular cell using high current pulse.
The PROM chip can be programmed only once and its contents cannot be erased.
PROM are flexible, faster and less expensive because they can be programmed directly by the user.
EPROM (Erasable Programmable Read Only Memory )
A rewritable chip that holds its contents without power. Previous data can be erased and new data can be inserted
EPROM chips are written on an external programming device before being placed on the circuit board. Capable of retaining stored information for a long time.
Eraser contd., requires breakup the charges trapped in the transistors of memory cell.[this is done by break the chip to ultraviolet light].
This reason EPROM packaged with transparent window.
Disadvantages: Entire EPROM is erased as a whole and selective erasing is not possible.
Should be removed from the chip for reprogramming.
Unlike the PROM, EPROM contents can be deleted after being programmed. Elimination is done by using ultraviolet light.
EEPROM (Electrically Erasable Programable Read Only Memory)
EEPROM can store data permanently, but its contents can still be erased electrically through the program. One type EEPROM is Flash Memory. Flash Memory commonly used in digital cameras, video game consoles, and the BIOS chip.
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Answer:
ROM
Read-only memory (ROM) is a type of non-volatile memory used in computers and other electronic devices. Data stored in ROM cannot be electronically modified after the manufacture of the memory device. Read-only memory is useful for storing software that is rarely changed during the life of the system, also known as firmware. Software applications (like video games) for programmable devices can be distributed as plug-in cartridges containing read-only memory.
RAM
Random-access memory (RAM /ræm/) is a form of computer memory that can be read and changed in any order, typically used to store working data and machine code.[1][2] A random-access memory device allows data items to be read or written in almost the same amount of time irrespective of the physical location of data inside the memory. In contrast, with other direct-access data storage media such as hard disks, CD-RWs, DVD-RWs and the older magnetic tapes and drum memory, the time required to read and write data items varies significantly depending on their physical locations on the recording medium, due to mechanical limitations such as media rotation speeds and arm movement.