Storing a string from code memory to IDATA memory in C (8051)

[adrianvon]

I have the following code of line which stores the string TesT in the code memory of the 8051 micro-controller.

char code *text_to_compare ="TesT";

How can I store the same string in the IDATA memory starting from 92Hex?

Any kind of help would be highly appreciated.
Thanks in advance.

 

[Ian Rogers]

Which compiler??? SDCC uses the __at to specify an absolute address.. However!! char *text_to_compare = "Test"; will store the string in IDATA..

Some compilers use @ to absolute address....#

I don't think using a pointer will work..

char _at (0x92) text_to_compare[] = {"Test"};
char *pointer_to_text = &text_to_compare[0];

Now pointer_to_text is what you need....

 

[adrianvon]

Thanks for the reply. The thing is that i need it to start from 92hex. char _at (0x92) text_to_compare[] = {"Test"}; did not work. I am using the C51 compiler.

 

[Ian Rogers]

struct link {
struct link idata *next;
char code *test;
};

struct link idata list _at_ 0x40; /* list at idata 0x40 */
char xdata text[256] _at_ 0xE000; /* array at xdata 0xE000 */
int xdata i1 _at_ 0x8000; /* int at xdata 0x8000 */
char far ftext[256] _at_ 0x02E000; /* array at xdata 0x03E000 */

void main ( void ) {
link.next = (void *) 0;
i1 = 0x1234;
text [0] = 'a';
ftext[0] = 'f';
}

The syntax is slightly different for c51... The documentation is very good
https://www.keil.com/support/man/docs/c51/c51_intro.htm