100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
Summary Memory - Lecture Notes (COMP15212) £8.48   Add to cart

Summary

Summary Memory - Lecture Notes (COMP15212)

 3 views  0 purchase

Gain a thorough understanding of memory concepts with these detailed lecture notes from COMP15212. Explore different types of memory, caching mechanisms, and memory management techniques, essential for anyone looking to excel in computer architecture and system performance.

Preview 1 out of 4  pages

  • May 29, 2024
  • 4
  • 2023/2024
  • Summary
All documents for this subject (5)
avatar-seller
jpxoi
Memory

Simple Memory Model Typical Example Memory Map (One Process' Virtual Address Space

Address Data
Each location has an address

and stores some data
.
00 12
m n
As





01 34 Fixed
Locala bles
size ;
Code Executable binary Read only
Here 02 00
we've
got 8-bit addresses Stack

(and data 03 FF
W W

Read-only Fixed size;

data
strings tables,
,
...




Of 48 i wo Read only

Allocated
05 65

Fixedsiza
&

I ↑ at run-time Static data Global variables ,




Of 6C
hexadecimal Dynamic
space
07 6C
Local Dynamici
Heap (possibly Stack variables
6 Read/write
08 F
fragmented)
09 00
Dynamic
* Heap Run time structures




!
&
OA
Read/write
A5
Global Data Read/write
- -




Read
Constants
only
.. --




Reserved by computer
-- ...




8-bitWestata
FE DE
Code Read only
↑ &

281 D
FF AD




OS
.
Restricted !
.




private
space




Processes Memory Management Sizes

Processes use an idealised set of virtual addresses
Processor architecture determines the size (#of locations) of the virtual

address space
OS Momony
These then mapped to
are
physical addresses
Management
Process * locations
Processes don't have to worry about where they are
**
Usually are 8-bit (bytes)
Software
in memory
MMU
Storage ,

0 1 1 101 O 1
Cache,
Memory RAM
Management
Unit
16-bit > 65356 addresses



32-bit > 4294967294 addresses


64-bit > 18446744073709551616 addresses




Mapping Virtual Addresses to Physical Addresses : Simple Approach Variable Partition


1280
, 000

OS OS OS OS

Operating Process 5 Process 5 Process 5 ??? p


System
D · Process 8 * Process 8 Process
a
896000 # base + limit Process 7

??? A


256000 Process 2
Process 2 Process 2 Process 2 Process 2
base
Process 2 64000 &




O Process 2
Virtual addresses Strategies
38400

First-fit :
Stop when you
find a hole big
Process 3
enough
base and limit registers 128000


base "Start" of physical Best-fit : Find the smallest hole big
:
O
enough
memory


limit : Size of range Worstfit Find : the largest hole

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

Guaranteed quality through customer reviews

Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.

Quick and easy check-out

Quick and easy check-out

You can quickly pay through credit card for the summaries. There is no membership needed.

Focus on what matters

Focus on what matters

Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!

Frequently asked questions

What do I get when I buy this document?

You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.

Satisfaction guarantee: how does it work?

Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.

Who am I buying these notes from?

Stuvia is a marketplace, so you are not buying this document from us, but from seller jpxoi. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for £8.48. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

79223 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy revision notes and other study material for 14 years now

Start selling
£8.48
  • (0)
  Add to cart