Memory & Memory units

What is Memory?

Memory devices are digital systems that store data either temporarily or for a long term. Digital computers to hard disks have built-in memory devices that can store the data of users or manufacturers. The data either be in the form of control programs or programs that boot the system. Hence, to store such a huge amount of data the memory devices must have enormous capacity. The challenge is to build memory devices that have large capacities but are cost-effective. The memory devices must be capable of storing both permanent data and instantaneous data....

Types of Computer Memory

Cache memory. This temporary storage area, known as a cache, is more readily available to the processor than the computer’s main memory source. It is also called CPU memory because it is typically integrated directly into the CPU chip or placed on a separate chip with a bus interconnect with the CPU. RAM.  It is one of the parts of the Main memory, also famously known as Read Write Memory. Random Access memory is present on the motherboard and the computer’s data is temporarily stored in RAM. As the name says, RAM can help in both Read and write. D RAM (Dynamic RAM): D RAM uses capacitors and transistors and stores the data as a charge on the capacitors. They contain thousands of memory cells. It needs refreshing of charge on capacitor after a few milliseconds. This memory is slower than S RAM. S RAM (Static RAM): S RAM uses transistors and the circuits of this memory are capable of retaining their state as long as the power is applied. This memory consists of the number of flip flops with each flip flop storing 1 bit. It has less access time and hence, it is faster. ROM: ROM full form is Read Only Memory. ROM is a non volatile memory and it is used to store important information which is used to operate the system. We can only read the programs and data stored on it and can not modify of delete it. MROM(Masked ROM): Hard-wired devices with a pre-programmed collection of data or instructions were the first ROMs. Masked ROMs are a type of low-cost ROM that works in this way. PROM (Programmable Read Only Memory): This read-only memory is modifiable once by the user. The user purchases a blank PROM and uses a PROM program to put the required contents into the PROM. Its content can’t be erased once written. EPROM (Erasable Programmable Read Only Memory): EPROM is an extension to PROM where you can erase the content of ROM by exposing it to Ultraviolet rays for nearly 40 minutes. EEPROM (Electrically Erasable Programmable Read Only Memory): Here the written contents can be erased electrically. You can delete and reprogramme EEPROM up to 10,000 times. Erasing and programming take very little time, i.e., nearly  4 -10 ms(milliseconds). Any area in an EEPROM can be wiped and programmed selectively. Virtual memory. A memory management technique where secondary memory can be used as if it were a part of the main memory. Virtual memory uses hardware and software to enable a computer to compensate for physical memory shortages by temporarily transferring data from RAM to disk storage....

Units of Memory

Memory units are used to measure the size and represent data. Some of the commonly used memory units are:...

Conversions of units

Name Equal To Size (In Bytes) Bit 1 Bit 1/8 Nibble 4 Bits 1/2 (rare) Byte 8 Bits 1 Kilobyte 1024 Bytes 1024 Megabyte 1024 Kilobytes 1, 048, 576 Gigabyte 1024 Megabytes 1, 073, 741, 824 Terabyte 1024 Gigabytes 1, 099, 511, 627, 776 Petabyte 1024 Terabytes 1, 125, 899, 906, 842, 624 Exabyte 1024 Petabytes 1, 152, 921, 504, 606, 846, 976 Zettabyte 1024 Exabytes 1, 180, 591, 620, 717, 411, 303, 424 Yottabyte 1024 Zettabytes 1, 208, 925, 819, 614, 629, 174, 706, 176...

Memory & Memory units – FAQs

1. What is memory unit in CPU?...