Search

Technical Discussion Group Forum

This forum is provided for user discussion. While Logic PD support staff and engineers participate, Logic PD does not guarantee the accuracy of all information within in the Technical Discussion Group (TDG).

The "Articles" forums provide brief Articles written by Logic PD engineers that address the most frequently asked technical questions.

To receive email notifications when updates are posted for a Logic PD product download, please subscribe to the TDG Forum of interest.

PrevPrev Go to previous topic
NextNext Go to next topic
Last Post 27 Feb 2007 12:42 PM by  kurtl@logicpd.com
Access to CompactFlash card?
 6 Replies
Sort:
You are not authorized to post a reply.
Author Messages
rbwinchell
New Member
New Member
Posts:


--
13 Feb 2007 08:27 AM
    Is there a sample/explaination/etc of how to access the CF card programatically (e.g. not through Lolo)?

    Thanks.
    ashwinb@logicpd.com
    New Member
    New Member
    Posts:


    --
    13 Feb 2007 01:33 PM
    You would want to access the CF within an OS? If so, which OS?
    rbwinchell
    New Member
    New Member
    Posts:


    --
    14 Feb 2007 07:47 AM
    Sorry I should have been more clear. I'd like to do this without using an OS, or using the Sharp BlueStreak library.

    I see that the CF only works in memory-mapped mode, so all I'm really interested in is how I access that at a basic level.
    rbwinchell
    New Member
    New Member
    Posts:


    --
    20 Feb 2007 09:31 AM
    I've gotten a bit further and I understand what is involved here.

    The problem I am having is that I can see the attribute memory of the CF card (0x4c700000), but if I try to read/write any of the card registers, I am getting bad data. Trying to write does not change the values. Any tips or ANY information would be appreciated.
    kurtl@logicpd.com
    New Member
    New Member
    Posts:


    --
    22 Feb 2007 11:22 AM
    The Sharp ARM7 and ARM9 CPUs do not deassert the chip select line to external devices upon consecutive accesses to the same area. Some devices require this, including CompactFlash devices. This may be partially related to your problem. To work around this you must insert dummy accesses to other external memory areas. This document provides further details.
    http://www.logicpd.com/do...AN_1003185_Rev_A.pdf
    rbwinchell
    New Member
    New Member
    Posts:


    --
    27 Feb 2007 12:37 PM
    I have this working now. Turns out it was a problem with the read/write timings getting set correctly for the CS3 area (write-enable line not being asserted long enough).
    kurtl@logicpd.com
    New Member
    New Member
    Posts:


    --
    27 Feb 2007 12:42 PM
    Good work!
    You are not authorized to post a reply.