ARM Technical Support Knowledge Articles

PROBLEMS WITH _AT_ ADDRESSES IN V2.12A

Applies to: C251 C Compiler

Answer

QUESTION

I just installed the DK251 V2.12A update and now my compiled code fails to operate the hardware. It appears that globals declared with the "_AT_" keyword have their actual addresses ignored or dropped in the final executable code. For example, the following code illustrates this problem:

unsigned volatile int xdata io_reg _at_ 0xff00;

void main()
        {
        unsigned int value;
        value = io_reg;
        io_reg = value & 0x00ff;
        }

ANSWER

This was a problem discovered in the C251 V2.12A release. This has been corrected in C251 V2.12F and later. Check the following URL for the latest update:

http://www.keil.com/update/

Article last edited on: 2004-05-20 20:09:48

Rate this article

[Bad]
|
|
[Good]
Disagree? Move your mouse over the bar and click

Did you find this article helpful? Yes No

How can we improve this article?

Link to this article
Copyright © 2011 ARM Limited. All rights reserved. External (Open), Non-Confidential