Email: Password: Remember Me | Create Account (Free)

Back to Subject List

Old thread has been locked -- no new posts accepted in this thread
Jim Granville
03/28/13 18:18
Read: 980 times

#189583 - Links and info
Responding to: Erez Hillel's previous message
Erez Hillel said:
hello i want to understand how the memory is organize i know that i have rom and ram.
but inside ram i have data memory and idata memory what is the difference are they the same memory?

Yes and no. data and idata are overlaid from 0..7FH and split from 80H..FFH.

Above 80H, SFR registers are mapped to data opcodes, and RAM exists > 80H on most parts these days, and is mapped only to the IDATA and Stack opcodes.

It can help to read more than one '51 data sheet.

Here are a couple from different authors.

List of 14 messages in thread
memory organizion      Erez Hillel      03/28/13 16:11      
   Links and info      Jim Granville      03/28/13 18:18      
   Bible time      Andy Neil      03/29/13 00:44      
      Does the link to "the bible" work nowadays?      Richard Erlacher      03/29/13 10:39      
         Why don't you try them?      Andy Neil      03/29/13 11:13      
            I'm not even sure where they are.       Richard Erlacher      03/30/13 11:25      
               Do pay attention, Richard      Andy Neil      03/31/13 07:22      
                  Of course, and they work fine.      Richard Erlacher      03/31/13 08:30      
                     That's why I gave the links!      Andy Neil      03/31/13 16:16      
                        What we have here is a failure to communicate ...       Richard Erlacher      04/01/13 09:35      
                           Sure But....        Michael Karas      04/02/13 06:39      
                              Yes - that is my point exactly      Andy Neil      04/02/13 07:49      
                                 I didn't consider that, either ... perhaps I should ...       Richard Erlacher      04/02/13 12:09      
                              Well, I didn't consider that ... sorry ...      Richard Erlacher      04/02/13 12:08      

Back to Subject List