#include#define OP_READ 0xa1 // 器件地址以及读取操作 #define OP_WRITE 0 // 器件地址以及写入操作 unsigned char code tab[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90}; int eepromdata; //从EEPROM里读出来的数据 sbit SDA = P3^4; sbit SCL = P3^3; void delay()ms(unsigned char ms) { unsigned char i; while(ms--) { for(i = 0; i < 120; i++); } } void delay()(void) { int k; for(k=0;k<400;k++); } void start() { SDA = 1; SCL = 1; _nop_(); _nop_(); SDA = 0; _nop_(); _nop_(); _nop_(); _nop_(); SCL = 0; } void stop() { SDA = 0; _nop_(); _nop_(); SCL = 1; _nop_(); _nop_(); _nop_(); _nop_(); SDA = 1; } unsigned char shin() { unsigned char i,read_data; for(i = 0; i < 8; i++) { SCL = 1; read_data <<= 1; read_data |= (unsigned char)SDA; SCL = 0; } return(read_data); } bit shout(unsigned char write_data) { unsigned char i; bit ack_bit; for(i = 0; i < 8; i++) { SDA = (bit)(write_data & 0x80); _nop_(); SCL = 1; _nop_(); _nop_(); SCL = 0; write_data <<= 1; } SDA = 1; _nop_(); _nop_(); SCL = 1; _nop_(); _nop_(); _nop_(); _nop_(); ack_bit = SDA; // 读取应答 SCL = 0; return ack_bit; // 返回AT24Cxx应答位 } void write_byte(unsigned char addr, unsigned char write_data) { start(); shout(OP_WRITE); shout(addr); shout(write_data); stop(); delay()ms(10); } unsigned char read_current() { unsigned char read_data; start(); shout(OP_READ); read_data = shin(); stop(); return read_data; } unsigned char read_random(unsigned char random_addr) { start(); shout(OP_WRITE); shout(random_addr); return(read_current()); } void display(int k) { P2=0xfe; //最高位数码管1234 P0=tab[k/1000]; delay(); P2=0xfd; P0=tab[k00/100]; delay(); P2=0xfb; P0=tab[k0/10]; delay(); P2=0xf7; P0=tab[k]; delay(); P2=0xff; } void main(void) { SDA = 1; SCL = 1; eepromdata=0; write_byte(0x01, 0x55); //向0x01地址写入0x55(85)的数据 delayms(250); write_byte(0x02, 0xAA); //向0x02地址写入0xAA(170)的数据 delayms(250); delayms(250); eepromdata= read_random(0x02); // 读取其中一个地址内的数据来验证 delayms(250); while(1) { display(eepromdata); } }
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