struct XPORT7
{
unsigned char X70:1;
unsigned char X71:1;
unsigned char X72:1;
unsigned char X73:1;
unsigned char X74:1;
unsigned char X75:1;
unsigned char X76:1;
unsigned char X77:1;
};
struct XPORT7 XP7;
union XXPORT7
{
unsigned char YP7;
struct XPORT7 XP7;
};
union XXPORT7 YPORT7;
这是什么意思啊