WHY the function _WBYTE don't work!

the codes like follow:
#include<absacc.h>
#include<reg52.h>
#define XRAMTEST XBYTE[0X1111]
main()
{
unsigned char t ;
t = XRAMTEST;
while(1);
}

when use the _WBYTE(0x1111,0x55) in the debug textbox.
when the code run to the line t = XRAMTEST.
but the variable t don't equ 0x55 but equ 0
why?
thanks !