#include <AT89S8252.H>

void main()
{
void SPI_out(int send,int l_add,int u_add);
void chip_command(int);
int i;
P1 = 0xFF;
SPCR = 0x53; /* SPI interrupt enable with micro as master and 1MHz data transfer rate */
SS = 0;
chip_command(0x06); /* Write Enable for external EEPROM */
SS = 1;
P1 &= 0xF0;
for(i = 0;i < 30000;i++);
SS = 0;
SPI_out(0x55,0x00,0x04); /* Send data, lower address and higher address */
SS = 1;
P1 |= 0x0F;
for(i = 0;i < 30000;i++);
SS = 0;
chip_command(0x04);
P1 = 0xFF;
}

void SPI_out(int send,int l_add,int u_add)
{
DPH = u_add;
DPL = l_add;
SPDR = 0x02;
while(SPSR != 0x80);
ACC = DPH;
SPDR = ACC;
while(SPSR != 0x80);
ACC = DPL;
SPDR = ACC;
while(SPSR != 0x80);
ACC = send;
SPDR = ACC;
while(SPSR != 0x80);
}

void chip_command(int command)
{
ACC = command;
SPDR = ACC;
while(SPSR != 0x80);
}