memswap.c

基于c51的SD驱动程序,在FAT32文件系统中.

#ifndef _FAT32_DEFINE
 #include "FAT32.c"
#endif

WORD MEMSwap16(WORD c);
DWORD MEMSwap32(DWORD c);

WORD MEMSwap16(WORD c)
{
    BYTE *c1;
    BYTE c2;
    c1 = (BYTE *)&c;
    c2 = c1[0];
    c1[0] = c1[1];
    c1[1] = c2;
    return(*((WORD *)c1));
}

DWORD MEMSwap32(DWORD c)
{
    BYTE *c1;
    BYTE c2;
    c1 = (BYTE *)&c;
    c2 = c1[0];
    c1[0] = c1[3];
    c1[3] = c2;
    c2 = c1[2];
    c1[2] = c1[1];
    c1[1] = c2;
    return(*((DWORD *)c1));
}