spi

SPDAT IS NOT DISPLAYING THE VALUE IT HAVE RECIEVED IN THE SIMULATOR

I hav written the comments plz go through it.

#include <REG51xD2.H>

void SPI(unsigned char);

void sdelay(int );
void main(void)
{

EA=1;
SPSTA=0x00;
SPCON=0xd6; /*MSTR(4th bit),SPEN(7th bit),CPHA(2nd bit),7th,0th & 1st bits are enbled. the 7th ,0th & 1st bits are enbled for Fclk Periph/128*/

IEN1=0x04; /* enable spi interrupt */

P1_7=1;/*mOsi enable*/
P1_6=1;/*sck enable*/
P1_1=1;/*slave select*/
sdelay(1);
SPI(0x80);/* send an example data */

sdelay(1);
while(1);
}

void SPI(unsigned char mybyte)
{

SPDAT=mybyte;/* read receive data */

while(!(SPSTA&0x80))/* set software flag */ { ; }

SPSTA&=0x7f;

}

void sdelay(int ms)
{ unsigned int i,j;
for(i=0;i<ms;i++)
for(j=0;j<135;j++);

}