eeprom.c

atmega8的片内eeprom读写操作程序

//ICC-AVR application builder : 2005-3-1 23:23:33
// Target : M8
// Crystal: 8.0000Mhz

#include <iom8v.h>
#include <macros.h>
#include <74164.h>
#include <eeprom.h>

unsigned char    display[4];  // 显示缓冲区
unsigned char    dis;         // 当前显示
unsigned char    s,m;          // 时间

//TIMER0 initialisation - prescale:256
// WGM: Normal
// desired value: 5mSec
// actual value:  4.992mSec (0.2%)
void timer0_init(void)
{
 TCCR0 = 0x00; //stop
 TCNT0 = 0x64; //set count
 TCCR0 = 0x04; //start timer
}

#pragma interrupt_handler timer0_ovf_isr:10
void timer0_ovf_isr(void)
{
 TCNT0 = 0x64; //reload counter value
//  display
    switch(dis){  //  显示
        case  0:  write164(display[dis] | 0x70);  break;
        case  1:  write164(display[dis] | 0xB0);  break;
        case  2:  write164(display[dis] | 0xD0);  break;
        case  3:  write164(display[dis] | 0xE0);  break;
    }
    if(++dis > 3) dis = 0;
//end  display
}

//TIMER1 initialisation - prescale:1024
// WGM: 0) Normal, TOP=0xFFFF
// desired value: 1Hz
// actual value:  1.000Hz (0.0%)
void timer1_init(void)
{
 TCCR1B = 0x00; //stop
 TCNT1H = 0xE1; //setup
 TCNT1L = 0x7C;
 OCR1AH = 0x1E;
 OCR1AL = 0x84;
 OCR1BH = 0x1E;
 OCR1BL = 0x84;
 ICR1H  = 0x1E;
 ICR1L  = 0x84;
 TCCR1A = 0x00;
 TCCR1B = 0x05; //start Timer
}

#pragma interrupt_handler timer1_ovf_isr:9
void timer1_ovf_isr(void)
{
 //TIMER1 has overflowed
 TCNT1H = 0xE1; //reload counter high value
 TCNT1L = 0x7C; //reload counter low value
 if(++s == 60){
   s = 0;
   if(++m == 60) m = 0;
 }
 EEPROMwrite(1,s);       //  保存时间
 EEPROMwrite(2,m);
 display[0] = s % 10;    //  刷新显示缓冲
 display[1] = s / 10;
 display[2] = m % 10;
 display[3] = m / 10;
}

//call this routine to initialise all peripherals
void init_devices(void)
{
 //stop errant interrupts until set up
 CLI(); //disable all interrupts
 DDRB = 0x01;    //  初始化操作74LS164的管脚
 DDRD = 0xC0;    //  初始化操作74LS164的管脚
 timer0_init();
 timer1_init();

 MCUCR = 0x00;
 GICR  = 0x00;
 TIMSK = 0x05; //timer interrupt sources
 SEI(); //re-enable interrupts
 //all peripherals are now initialised
}

//
void main(void)
{
 init_devices();
 s = EEPROMread(1);  //  读取时间
 m = EEPROMread(2);
 display[0] = s % 10;    //  刷新显示缓冲
 display[1] = s / 10;
 display[2] = m % 10;
 display[3] = m / 10;
 while(1);
}