This document discusses different types of computer memory. It describes dynamic RAM (DRAM) which must be refreshed to maintain data and static RAM (SRAM) which retains data permanently. It also discusses the "memory wall" where CPU speed increased much faster than memory speed. Flash memory is described as a type of non-volatile memory used in devices like USB drives. The document concludes by defining non-volatile RAM (NVRAM) and providing examples like FeRAM and PRAM.

1. COURSEWORK 1
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2. COURSEWORK 2
Coursework
A. Dynamic RAM is the type of memory that uses memory cells holding one bit of
information. DRAM chip is made of two parts (a transistor and a capacitor). Each capacitor is
designed to store 1 or 0 (filled with electrons). It is charged and discharged according to the
needs of CPU or memory controller. Thus, the memory is refreshed thousands of times per
second to hold information in it. Static RAM does not need to be refreshed because
information is stored in 4-6 capacitors permanently (HowStuffWorks.com, 2011).
B. The term “memory wall” describes the difference in performance of CPU and
memory. The thing is that since 1986 to 2000 the speed of CPU grew up to 55%; memory
speed grew only up to 10% for the same period. “Given these trends, it was expected that
memory latency would become an overwhelming bottleneck in computer performance.”
(Archmemory.com, 2010). Today, memory wall is not that critical due to the fact that the
development of CPU technologies slowed down significantly and current design of CPUs has
already reached this wall in some meaning.
C. Flash memory work principle is based on the electrically erasable programmable read-
only memory (EEPROM) that is also known as non-volatile. One of the restrictions of its
application is the necessity to erase it in rather large blocks before they can be filled with new
information. It has two types: NAND and NOR. Flash memory invention allowed
miniaturizing most of the electronic gadgets of these days (USB drives, mobile phones, etc.).
D. Non-volatile random-access memory (NVRAM) is based on technology retaining
information in case power is turned off. The best example of NVRAM is flash memory.
Ferroelectic RAM (FeRAM) is similar to DRAM but it uses ferroelectric technology instead
of dielectric in order to achieve non-volatility. Phase-change memory (PRAM) is another
type of NVRAM. It uses chalcogenide glass as the layer to achieve non-voliatility.

3. COURSEWORK 3
References
Archmemory.com (2010). Computer RAM. Retrieved from:
http://www.archmemory.com/page.cfm/RAM%20Definition
HowStuffWorks.com (2011). What is the difference between static RAM and dynamic
RAM? Retrieved from: http://computer.howstuffworks.com/question452.htm