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Seminar
On
RANDOM ACCESS
MEMORY (RAM)

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 Types of ram

• Static RAM
• Dynamic RAM
 Limitation of ram

 Future of RAM

 Reference
RANDOM ACCESS MEMORY
Random Access Device allows stored data to be accessed directly in any
random order. RAM is type of temporary storage media. It does not
store data permanently. It is a type of Volatile memory. This means that
RAM loses all its data once the power is turned off.
How Does It Work ?
 When the computer first starts a program it sends an address to RAM
to begin retrieving that program. The RAM address just consist a
series of 1’s and 0’s representing ‘ON’ and ‘OFF’ wire.
 RAM does not do anything with that address until the CPU turns on
the “SET” or “ENABLE” wire. If the enable wire is turned ON the
RAM automatically senses the data corresponding to that address
back to the CPU, that data is then processed by the CPU accordingly.
TYPES OF RAM

RAM is basically of two types:

 Dynamic RAM

Static RAM is a type of RAM that keeps the data fed to it. It
never has to be refreshed. This makes static RAM significantly
faster than dynamic RAM . Static memory cell takes up a lot
more space on a chip than a dynamic memory cell. This makes
Static RAM expensive than DRAM.
On the other hand, Dynamic RAM constantly needs to be
refreshed otherwise the stored data will be lost.
TYPES OF DRAM
 FRM DRAM (Fast Page Mode Dynamic Random Access Memory):-
It was the original form of DRAM. It waits through the entire process of
locating a bit of data by column and row and then reading the bit before
it starts on the next bit. Maximum transfer rate to L2 cache is
approximately 176 Mbps.
 EDO DRAM (Extended data-out Dynamic Random Access Memory)
does not wait for all of the processing of the first bit before continuing to
the next one. As soon as the address of the first bit is located, EDO
DRAM begins looking for the next bit. It is about five percent faster than
FPM. Maximum transfer rate to L2 cache is approximately 264 Mbps.
 SDRAM is a type of dynamic random access memory which is
synchronized with the clock speed that the microprocessor is
optimized for. SDRAM is about five percent faster than EDO RAM
and is the most common form in desktops today. Maximum transfer
rate to L2 cache is approximately 528 Mbps.
 DDR SDRAM: Double data rate synchronous dynamic RAM is
just like SDRAM except that is has higher bandwidth, meaning
greater speed. It is a newer variant of SDRAM. Maximum transfer
rate to L2 cache is approximately 1,064 Mbps .
 random access memory : Designed by Rambus, RDRAM uses a Rambus
in-line memory module (RIMM), which is similar in size and pin
configuration to a standard DIMM. RDRAM memory chips work in parallel
to achieve a data rate of 800 MHz, or 1,600 Mbps. Since they operate at such
high speeds, they generate much more heat than other types of chips .
WHAT IS CACHE ?
Cache Memory is fast memory that serves as a buffer between the
processor and main memory. The cache holds data that was recently
used by the processor and saves a trip all the way back to slower main
memory. Types of Cache are:
 L1 Cache

 L2 Cache

 L3 Cache
MEMORY HIERARCHY
The memory structure of PCs is
often thought of as just main
memory, but it's really a five or six
level structure.
The first two levels of memory are
contained in the processor itself
consisting of the processor's small
internal memory, or registers, and
L1 cache, which is the first level of
cache, usually contained in the
processor.
 The third level of memory is the L2 cache, usually contained on the
motherboard.
 The fourth level, is being referred to as L3 cache. This cache used to
be the L2 cache on the motherboard, but now that some processors
include L1 and L2 cache on the chip, it becomes L3 cache. Usually, it
runs slower than the processor, but faster than main memory.
 The fifth level (or fourth if you have no "L3 cache") of memory is the
main memory itself.
 The sixth level is a piece of the hard disk used by the Operating
System, usually called virtual memory. Most operating systems use
this when they run out of main memory,
LIMITATION OF RAM
 One of the biggest drawback of Random Access Memory is that it is a
volatile memory. This means that whenever the computer is switched
off all the data that was stored in the RAM is lost.
 Another limitation of RAM is space limitation. The cost per bit for
RAM is high as compared to ROM, because of this reason it is not
used for mass storage.
CONCLUSION
 The amount of RAM matters more than the type of RAM. This is
because more the RAM available in a system, more number of tasks
can be performed simultaneously without any performance drop.
 Computers used nowadays comes with DDR2, DDR3 RAM. While
RDRAM did not become popular due to high licensing fees, high
cost, being a proprietary standard, and low performance advantages
for the increased cost. It is being used in some graphics accelerator
boards in place of VRAM and is also being employed in Intel’s
Pentium III Xeon processors
 FUTURE OF RAM…

 Future computers and electronic gadgets will need memory chips that are smaller, faster
and cheaper than those of today .
 RRRAM (Resistive RAM) and Z-RAM (Zero-capacitor RAM) are runners in the global
technology race as the next generation RAM.
 Innovative Silicon, developer of Z-RAM claims the technology offers memory access
speeds similar to a standard SDRAM used in cache memory but uses only a single
transistor, therefore affording much higher packing densities.
 On the other hand crossbar , a U.S based tech firm claims to have achieved a "simple and
scalable" memory cell structure of RRAM consisting of three layers. The structure means
cells can be stacked in 3D, squeezing terabytes of storage capacity onto a single chip the
size of a postage stamp
Reference
 www.google.com
 www.wikipedia.org
 www.studymafia.org
THANK
YOU