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Student Name: Alia Hussain Abu Al Rahi
ID #: 201101164
Major: Information Technology
Instructor Name: wisal Ali
Memory
What is a memory?
Memory is the process by which information is encoded, stored,
and retrieved.
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Encoding or registration: receiving, processing and
combining of received information.
Storage: creation of a permanent record of the encoded
information.
Retrieval, recall or recollection: calling back the stored
information in response to some cue for use in a process or
activity.
What are the types of memory?
Memory has two types which are:
1. Random Access Memory (RAM).
2. Read Only Memory (ROM).
Random Access Memory:
Is a form of computer data storage. A random-access
device allows stored data to be accessed quickly in any
random order. In contrast, other data storage media such
as hard disks, CDs, DVDs and magnetic tape, as well as
early primary memory.
Random access memory has two types:
1. Dynamic memory:
Is a type of random-access memory that stores each bit of
data in a separate capacitor within an integrated circuit.
2. Static Memory:
Is a type of semiconductor memory that uses bistable
latching circuitry to store each bit. The term static
differentiates it from dynamic RAM (DRAM) which must be
periodically refreshed. SRAM exhibits data permanence, but
it is still volatile in the conventional sense that data is
eventually lost when the memory is not powered.
Read Only Memory:
Is a class of storage medium used in computers and other
electronic devices. Data stored in ROM cannot be modified,
or can be modified only slowly or with difficulty, so it is
mainly used to distribute firmware.
Read Only Memory has two three types:
 Programmable Read Only Memory:
A programmable read-only memory (PROM) nonvolatile memory (NVM) is a form of digital memory
where the setting of each bit is locked by a fuse or ant
fuse. Such PROMs are used to store programs
permanently. The key difference from a strict ROM is
that the programming is applied after the device is
constructed.
 EPROM:
Erasable programmable read only memory, is a type of
memory chip that retains its data when its power
supply is switched off. In other words, it is non-volatile.
It is an array of floating-gate transistors individually
programmed by an electronic device that supplies
higher voltages than those normally used in digital
circuits. Once programmed, an EPROM can be erased
by exposing it to strong ultraviolet light source.
 EEPROM:
Is user-modifiable read-only memory (ROM) that can
be erased and reprogrammed (written to) repeatedly
through the application of higher than normal
electrical voltage generated externally or internally in
the case of modern EEPROMs. EPROM usually must be
removed from the device for erasing and
programming, whereas EEPROMs can be programmed
and erased in-circuit.