need help on spi mode on p89v51 for sd card

#include <stdio.h>
#include <p89v51rd2.h>

void spi_init()
{
        P1 = 0xBF;                       // defines i/o pins
        SS = 1;                          // sets the chip select pin high
        SPCFG = 0x00;                    // clears spi flag
        SPCTL = 0x5B;                    // selecting master mode and other configurations
}

void main()
{
        spi_init();                      // spi mode initialization
        while(1)
        {
        SS = 0;
        SPDAT = 0xAA;                    // sends AAh to slave device
        while (!(SPCFG & 0x80));
        SPCFG =0x00;
        SS = 1;
        }
}