eeprom.c

a gps program

/*** BeginHeader */
#ifndef __EEPROM_C
#define __EEPROM_C

#include "includes.h"
#include "eeprom.h"

sbit cs_93 = P3^7;
sbit sk_93 = P2^7;
sbit di_93 = P2^6;
sbit do_93 = P2^5;

void delay(uint num)
{
    while(num != 0)
	    num -= 1;
}

void send(uint dat, int num)
{
    int i;
    dat = dat << (16 - num);
	for (i = 0; i < num; i++) {
	    if ((dat & 0x8000) == 0)
		    di_93 = 0;
		else
		    di_93 = 1;
		sk_93 = 1;
		_nop_(); _nop_();
		_nop_(); _nop_();
		sk_93 = 0;
		dat = dat << 1;
	}
}

uchar read(uint address)
{
	uchar temp;
	int i;
    di_93 = 0;
    cs_93 = 0;
	sk_93 = 0;
	delay(5);
	cs_93 = 1;
	send((0x0c00 | address), 12);
	temp = 0;
	for (i = 0; i < 8; i++) {
	    temp = temp << 1;
		sk_93 = 1;
		sk_93 = 0;
		if (do_93)
		    temp = temp | 0x01;
	}
	cs_93 = 0;
	return temp;
}

uchar write(uint addr, uchar dat)
{
    uchar temp;
	uint i;
	di_93 = 0;
	cs_93 = 0;
	sk_93 = 0;
	delay(5);
	cs_93 = 1;
	send(0x0980, 12);
	cs_93 = 0;
	delay(5);
	cs_93 = 1;
	send((0x0a00 | addr), 12);
	send(dat, 8);
	cs_93 = 0;
	cs_93 = 1;
	temp = 1;
	i = 50000;
	while (!do_93) {
	    i--;
		if (i == 0) {
		    temp = 0;
			break;
		}
	}
	cs_93 = 0;
	delay(5);
	cs_93 = 1;
	send(0x0800, 12);
	cs_93 = 0;
	return temp;
}

void DelayMs(uchar t)
{
    uchar j;
    while (t--) {
        for (j=0;j<125;j++);
    }
}

#endif // __EEPROM_C

/*** EndHeader */