1.iic 方式
/*--------------------------24C01的IIC 讀寫的c51程序----------------------------------------------------
程序中很多NOP是冗余的,希望讀者能進一步精簡,但必須經過驗證。
Atmel 24C01 比較特殊,為簡約型.
51晶振為11.0592MHz
-----------------------------------------------------------------------------*/
#include "reg51.h"
#include "intrins.h"
sbit SCL= P1^5;
sbit SDA= P1^4;
delay()
{
unsigned int i=1200;
while(i--);
}
/*----------------------------------------------------------------------------
調用方式：write_8bit(unsigned char ch) ﹫2001/03/23
函數說明：內函數,私有,用戶不直接調用。
-------------------------------------------------------------------------------
*/
void write_8bit(unsigned char ch)
{
unsigned char i=8;
SCL=0;
_nop_();_nop_();_nop_();_nop_();_nop_();
while (i--)
{
SDA=(bit)(ch&0x80);
_nop_();_nop_();_nop_();_nop_();_nop_();
ch<<=1;
SCL=1;
_nop_();_nop_();_nop_();_nop_();_nop_();
SCL=0;
_nop_();_nop_();_nop_();_nop_();_nop_();
}
_nop_();_nop_();_nop_();_nop_();_nop_();
_nop_();_nop_();_nop_();_nop_();_nop_();
}
/*------------------------------------------------------------------------------
調用方式：void ACK(void) ﹫2001/03/23
函數說明：內函數,私有,用戶不直接調用。
-------------------------------------------------------------------------------
*/
void ACK(void)
{
unsigned char time_1;
SDA=1;
SCL=0;
_nop_();_nop_();_nop_();_nop_();_nop_();
SCL=1;
time_1=5;
while(SDA) {if (!time_1) break;} //ACK
SCL=0;
_nop_();_nop_();_nop_();_nop_();_nop_();
}
unsigned char ReadIIC_24C01(unsigned char address)
{
unsigned char ddata=0;
unsigned char i=8;
SCL=1;
_nop_(); _nop_(); _nop_(); _nop_(); _nop_(); _nop_(); //Tsu:STA
SDA=0;
_nop_();_nop_();_nop_();_nop_();_nop_();_nop_(); //Thd:STA
SCL=0; //START
write_8bit( (address<<1) | 0x01); //寫頁地址和操作方式
ACK();
while (i--)
{
SDA=1;
ddata<<=1;
SCL=0;_nop_();_nop_();_nop_();_nop_();_nop_();SCL=1;
if (SDA) ddata|=0x01;
}
SCL=0;_nop_();SCL=1;_nop_();_nop_();_nop_();_nop_();_nop_();_nop_();
SDA=0;_nop_();SCL=1;_nop_();_nop_();_nop_();_nop_();_nop_();_nop_();
SDA=1; //STOP
delay();
return ddata;
}
void WriteIIC_24C01(unsigned char address,unsigned char ddata)
{
SCL=1;
_nop_(); _nop_(); _nop_(); _nop_(); _nop_(); _nop_(); //Tsu:STA
SDA=0;
_nop_();_nop_();_nop_();_nop_();_nop_();_nop_(); //Thd:STA
SCL=0; //START
write_8bit( (address<<1) & 0xfe); //寫頁地址和操作方式,對于24C32－
24C256,page不起作用
ACK();
write_8bit(ddata); //發送數據
ACK();
SDA=0;
_nop_();SCL=1;_nop_();_nop_();_nop_();_nop_();_nop_();_nop_();
SDA=1; //STOP
delay();
}
2.這是一個讀寫24C系列EEPROM的程序，已經經過本人親自測試，通過�。。。�！
//*************************************
//** M2401,M2402,M2404,M2408,M2416,M2432,M2464,M24128,M24256
//** 21c01,24c02:1010A2A1A0R/W; 24C04:1010A2A1P0R/W; 24C08:1010A2P1P0R/W
//** 24C16:1010P2P1P0R/W; //** 以上6種芯片的讀寫格式為：start-device addr-ack-first word addr-ack-second word addr-ack-data-ack-stop
//** 進行讀寫的字節數，EEPROM首址，EEPROM控制字節，
//** 以及EEPROM類型。此程序結構性良好，具有極好的容錯性，程序機器碼也不多:
//** 以上5種芯片的讀寫格式為：start-device addr-ack-word addr-ack-data-ack-stop
//** 24c32-24c512:1010A2A1A0R/W; 24C1024:1010A2A1P0R/W; 24c1024:1010A2A1P0R/W //** 通用的24C01－24C1024共11種EEPROM的字節讀寫操作程序，
//**************************24C01讀寫的c51源程序***********************************
＃i nclude <reg51.h>
＃i nclude <string.h>
＃i nclude <stdio.h>
＃i nclude <intrins.h>
sbit SDA =P1^1;
sbit SCL =P1^4;
sbit WP =P1^7;
sbit light =P1^0;
sbit power =P1^6;
#define uchar unsigned char
#define uint unsigned int
void iic_delay10ms();
void iic_delay(void);
void iic_start(void);
void iic_stop(void);
void iic_ack(void);
void read_byte(void);
void send_byte(void);
void initial(void);
void ok(void);
void error(void);
void read_eeprom(void);
void write_eeprom(void);
void init(void);
uchar ack_flag,send_data,receive_data[32];
uchar rw,type,device_addr,addr[3],num;
void main(void)
{
initial();
power =0;
light =0;
while(1)
{
ES =1;
rw =0x55;
WP =0;
while(rw ==0x55);
ES =0;
switch(type)
{
case 0x01:
case 0x02:
case 0x04:
case 0x08:
case 0x16:
type =0x02;
addr[1] |=0xa0;
device_addr <<=1;
addr[1] |=device_addr;
break;
default:
type =0x03;
addr[2] |=0xa0;
device_addr <<=1;
addr[2] |=device_addr;
}
if(rw ==0x01) //讀EEPROM
{
read_eeprom();
}
else if(rw ==0x00) //寫EEPROM
{
write_eeprom();
}
else //error command
{
error();
ACC =0x01;
SBUF =ACC;
while(!TI);
TI =0;
}
}
}
void read_eeprom(void)
{
uchar i;
WP =1;
iic_start();
for(i=1;i<=type;i++)
{
send_data =addr[type-i];
send_byte();
iic_ack();
if(ack_flag ==0x01)
break;
}
if(ack_flag ==0x00)
{
iic_start();
addr[type-1] |=0x01;
send_data =addr[type-1];
send_byte();
iic_ack();
if(ack_flag ==0x00)
{
for(i=0;i<num;i++)
{
read_byte();
SBUF =send_data;
while(!TI);
TI =0;
SDA =0;
SCL =1;
iic_delay();
SCL =0;
}
iic_stop();
rw =0x55;
}
else
{
error();
ACC =0x03;
SBUF =ACC;
while(!TI);
TI =0;
}
}
else
{
error();
ACC =0x02;
SBUF =ACC;
while(!TI);
TI =0;
}
}
//如果你對本程序或者24C01讀寫還有什么疑問，歡迎到http://m.izizhuan.cn的論壇去交流。
void write_eeprom(void)
{
uchar i;
WP =0;
iic_start();
for(i=1;i<=type;i++)
{
send_data =addr[type-i];
send_byte();
iic_ack();
if(ack_flag ==0x01)
break;
}
if(ack_flag ==0x00)
{
for(i=0;i<num;i++)
{
send_data =receive_data[i];
send_byte();
iic_ack();
iic_delay10ms();
}
iic_stop();
rw =0x55;
}
else
{
error();
ACC =0x04;
SBUF =ACC;
while(!TI);
TI =0;
}
}
void read_byte(void)
{
uchar i,temp=0x80;
send_data =0x00;
SCL =0;
for(i=0;i<8;i++)
{
SDA =1;
SCL =1;
if(SDA)
send_data |=temp;
temp/=2;
SCL =0;
iic_delay();
}
}
void send_byte(void)
{
uchar i,temp=0x80;
for(i=0;i<8;i++)
{
if((send_data&temp)==temp)
{
SDA =1; //sda=1
}
else
{
SDA =0; //sda=0
}
temp /=2;
iic_delay();
SCL =1;
iic_delay();
SCL =0;
iic_delay();
}
}
void iic_start(void)
{
SDA =1;
SCL =1;
WP =0;
iic_delay();
SDA =0;
iic_delay();
SCL =0;
}
void iic_stop(void)
{
SDA =0;
SCL =1;
iic_delay();
SDA =1;
//WP =1;
}
void iic_ack(void)
{
ack_flag =0x00; //ack_flag等于0x00時有應答
SDA =1;
iic_delay();
SCL =1;
iic_delay();
if(SDA)
{
ack_flag =0x01;
}
SCL =0;
}
void iic_delay(void)
{
_nop_();
_nop_();
_nop_();
_nop_();
}
void iic_delay10ms(void)
{
#pragma ASM
mov r6,#200
mov r7,#10
delay:
nop
nop
nop
djnz r6,delay
mov r6,#200
djnz r7,delay
#pragma ENDASM
}
void initial(void)
{
TMOD =0x21;
TH1 =0xfd;
TL1 =0xfd;
TH0 =0xfd;
TL0 =0xfd;
SCON =0x50;
TR1 =1;
EA =1;
ES =1;
ET0 =1;
PT0 =1;
}
void ok(void)
{
ACC =0x55;
SBUF =ACC;
while(!TI);
TI =0;
ACC =0xaa;
SBUF =ACC;
while(!TI);
TI =0;
}
void error(void)
{
ACC =0xaa;
SBUF =ACC;
while(!TI);
TI =0;
ACC =0x55;
SBUF =ACC;
while(!TI);
TI =0;
rw =0x55;
}
void es_int(void)interrupt 4
{
uchar i;
RI =0;
type =SBUF; //型號
while(!RI);
RI =0;
device_addr =SBUF; //器件地址
for(i=0;i<3;i++)
{
while(!RI);
RI =0;
addr[2-i] =SBUF; //地址高、中、低位字節
}
while(!RI);
RI =0;
num =SBUF; //要操作的字節數
while(!RI);
RI =0;
rw =SBUF;
if(rw ==1) //接收到要讀的命令
{
ok();
}
else //接收到要寫的命令
{
for(i=0;i<num;i++)
{
while(!RI);
RI =0;
receive_data[i]=SBUF;
}
ok();
}
//else
//{
// error();
//}
}