Week 5 Discussion

 

Cache and Memory Mapping

 

 

Part I

Consider a computer that you have used or now use. (You may make an assumption on word size if needed.)

·          How large is the memory of the computer?

·          How long is a word in the computer above?

·          How many bits are required to address the bytes in that memory?

·          How many data lines are required to read data from the computer memory?

 

 

Part II

·          Does your computer have cache?

·          If so how big is it?

·          How does your cache size compare with the size of main memory?

·          Do you know what kind of cache it is?

·          How did you find out about your computer's cache?

 Make an assumption that your cache is either:

·          Fully associative

·          Direct mapped

·          Two-way set-associative

·          Four-way set-associative

 Using the relationships in Part I above, determine:

 the size of the Tag and Word for Associative cache;

 OR

 the size of the Tag, Line, and Word for Direct-Mapped Cache ;

 Or

 the size of Tag, Set, and Word for K-Way Set-Associative Cache.

 

You may make any assumptions necessary including the number of Words in each block (recommend 2 or 4 or 8)

 

 

Part III

Given the following:

·          Logical Memory size of 1000

·         Physical Memory size of 2000

·         Page (and frame) size of 100

·         Block A contains data for a program

Select Block A’s size and its starting point in both memories. Then write the page table for Block A based on your selections.  

See below for the layout of both memories and an example of Block A of size 200.

 

Logical Memory                               Physical Memory

location/ page                                    location/frame

 

 

 

 

 

Part IV

 

Discuss the pros and cons of paging.