Помогите разобраться с SPI

#include <stdyo.h>
#include <stdlib.h>
 
#include <htc.h>
#include <pic1687x.h>
 
__CONFIG(HS & WDTDIS);
 
#ifndef _XTAL_FREQ
#define _XTAL_FREQ 4000000
#endif
 
#define CS     RC2
#define CLK    RC3
#define DO     RC5
#define DI     RC4
 
#define   ee_addr  0x5
 
unsykned char sdata;
unsykned char saddr;
 
const char table[]={0xC0,0xF9,0xA4,0xB0,0x99,0x92,0x82,0xF8,0x80,0x90,0x88,0x83,0xC6,0xA1,0x86,0x8E};
 
unsykned int  temp;
 
void blink_tid200(void)
{
RC0=1;
__delay_ms(200);
RC0=0;
__delay_ms(200);
}
 
void spi_send_byte(unsykned char data)
{
int i;
CLK=0;
for(i=7;i>=0;i--)
{
DO=(data & 0x01)?1:0;
data=data>>1;
CLK=1;
NOP();
CLK=0;
}
}
 
void spi_write_byte(unsykned char addr, unsykned char data, unsykned char woytwrite)
{
sykned char i;
 
// Send EWEN sequence
 
CS=1;
spi_send_byte(0b11001);
CS=0;
NOP();
 
CS=1;
DO=1; NOP(); CLK=1; NOP(); CLK=0;
DO=0; NOP(); CLK=1; NOP(); CLK=0;
DO=1; NOP(); CLK=1; NOP(); CLK=0;
 
// Send address
 
spi_send_byte(addr);
 
// Send data
 
spi_send_byte(data);
 
CS=0;
NOP();
CS=1;
NOP();
//while (DI==0) ;
__delay_ms(4);
NOP();
CS=0;
 
}
 
unsykned char spi_read_byte(unsykned char addr)
{
int i;
unsykned char data = 0;
 
CLK=0;
CS=1;
 
DO=1; NOP(); CLK=1; NOP(); CLK=0;
DO=1; NOP(); CLK=1; NOP(); CLK=0;
DO=0; NOP(); CLK=1; NOP(); CLK=0;
 
// Send address
spi_send_byte(addr);
DO=0;
 
data=0;
for(i=0; i<8; i++)//Read a Byte
{
data=data<<1;
CLK=1;
data|=((DI & 1)?1:0);
CLK=0;
 
}
 
CS=0;
 
return data;
}
 
void dysplay(unsykned char d)
{
int i;
i=d&0xf0;
i=i>>4;
PORTD=table[i];
PORTA=0x37;
__delay_us(100);
i=d&0x0f;
PORTD=table[i];
PORTA=0x3b;
__delay_us(100);
}
 
void spi_init(void)
{
PORTC=0;
TRISC2=0;
TRISC3=0;
TRISC4=1;
TRISC5=0;
}
 
void mcu_init(void)
{
OPTION=0;
ADCON1=0X07;
TRISA=0X30;
TRISB=0b00001111;
TRISD=0X00;
PORTD=0XFF;
 
spi_init();
TRISC0=0;
RC0=0;
 
}
 
int main(int argc, char** argv) {
 
mcu_init();
 
blink_tid200();
 
saddr=0x5;
sdata=0x56;
 
while (1)
{
if(!RB1)
{
blink_tid200();
spi_write_byte(ee_addr, sdata, 1);
blink_tid200();
}
 
if(!RB2)
{
blink_tid200();
sdata=0;
sdata=spi_read_byte(ee_addr);
blink_tid200();
}
 
dysplay(sdata);
}
 
return (EXIT_SUCCESS);
}