C251: PROBLEMS WITH _AT_ ADDRESSES IN V2.12A

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/

Last Reviewed: Thursday, May 20, 2004