bugProgramming from the Ground Up Book - Bugs: bug #24796, Page 15-16 - ver 1.0 booksize:...

 
 

bug #24796: Page 15-16 - ver 1.0 booksize: Indirect addressing

Submitter:  dusty <decline0>
Submitted:  Mon 10 Nov 2008 04:00:36 AM UTC
   
 
Category:  None Severity:  3 - Normal
Priority:  5 - Normal Item Group:  None
Status:  None Privacy:  Public
Assigned to:  None Open/Closed:  Open
* Mandatory Fields

Post a Comment

Add a New Comment Rich Markup
   

Discussion

Mon 10 Nov 2008 04:00:36 AM UTC, original submission:  

On pages 15 and 16 while detailing what indirect addressing is, the book tries to compare direct and indirect addressing.  It is very confusing.  The book says:

"In the indirect addressing mode, the instruction contains a register that contains a pointer to where the data should be accessed. for example, if we used indirect addressing mode and specified the %eax register, and the %eax register contained the value 4, whatever value was at memory location 4 would be used. In direct addressing, we would just load the value 4, but in indirect addressing, we use 4 as the address to use to find the data we want".

When the book says "we would just load the value 4", it doesn't sound like direct addressing.  It sounds like immediate mode. And "we use 4 as the address to use to find the data we want" sounds more like what direct addressing is rather than indirect.
I think wording it like this is clearer:

"In direct addressing, we use an immediate mode number as the address to use to find the data we want. In indirect addressing, we use the number stored in a register as a pointer to the data we want."

This is my first book on assembly so either I don't have a clue as to what I'm talking about or I can see the text from a beginner's view point better than the experts who wrote it.  What do you think?

dusty <decline0>

 

Attached Files

This item currently has no attached files.

(Note: upload size limit is set to 16MiB, after insertion of the required escape characters.)

Attach Files:
   
   
Comment:
   

 

Dependencies

This item does not depend on any other items.

No items depend on this one.

 

Mail Notification Carbon-Copy List

Carbon-Copy List
  • -email is unavailable- added by decline0 (Submitted the item)
  •  

    Votes

    There are 0 votes so far. Votes easily highlight which items people would like to see resolved in priority, independently of the priority of the item set by tracker managers.

    Only logged-in users can vote.

     

    History

    No changes have been made to this item

    Back to the top

    Powered by Savane 3.16.
    Corresponding source code