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DS80C400 doesnt show 400000 content.

gem xxx

Hi,
I have D80c400 evaluation kit and I am tring to read memory location 400000h.
According to application note 606. The controller stores 'TINI' hex values, but when I read the loaction I am not getting the same value as mentioned.

unsigned char *ptrROM;
unsigned int locationCounter;
ptrROM = (unsigned char *)0x400000h;
for(locationCounter =0; locationCounter<9;locationCounter++)
printf("\r\ ROM value at = %x", *(ptrROM++));

  • 0

    HI.

    it is a long long time now when i did 80c400. but i know and understand yo're problem.

    u set the pointer to 0x400000 but the run time librarie will acccess one of

    0x410000

    or

    0x3F0000

    sorrey but i can not remember teh detail.

    the high byte is (of thfree) is use for generic pointer in keil.

    u must look at the docmuents from the c libs.

    this is relevent;

    7. If you write any 8051 code that will be called from C, note that pointers as they are passed down from C code aren't immediately usable in 8051, and pointers that are usable in 8051 must be altered before they are suitable for C use. Use the macro FIXKEILPOINTER to change the high byte of a pointer passed down from C into something usable in 8051. For example, if the pointer is passed to assembly in r3:r2:r1...
    FIXKEILPOINTER r3
    The parameter should be the register or direct that contains the high byte of the pointer. To alter a pointer back so it can be returned to the C program... UNFIXKEILPOINTER r3

    Always yo're Freind.

    Zeusti.

  • 0 in reply to Advanced Zeusti

    Thanks a lot for your response.
    I gone through the document but they had not mention anything about how to use that macro in C file.
    I am using µVision3v3.53 and wanted to know, wether this version provide support for 24 bit addressing mode.

  • 0 in reply to gem xxx

    HI.

    wen i worked with it keil did a dk51 and a pk51.

    teh pk51 woz the pro version and had 24 bit.

    i c keil do pk51 and ca51 now.

    u need pk51.

    u also need 2 look at the maxim dallas c libs documants 4 the 80c400.

    i remembar their are c macros 4 the addresesses but i do not remembar teh names.

    good luck.

    Always yo're freind.

    Zeusti.

  • 0 in reply to Advanced Zeusti

    HI.

    the tini c libs ar at

    ftp.dalsemi.com/.../index.html

    and one about 24 bit pointers at

    files.dalsemi.com/.../structFARPTR.html

    plz read thru it. i did not use these C macros bcoz i did a lot in assemblar for my memory accesses

    Always yo're freind.

    Zeuisti.