PIC單片機之I2C（從模式）

7,使能I2C中斷

PIE1bits.SSP1IE = 1;//Enabe interrupt MSSP

INTCONbits.PEIE = 1;

INTCONbits.GIE = 1;

如果你要使用PIC單片機I2C從模式只要使用下面的代碼：

將void i2c_salve_interrupt_tx();void i2c_salve_interrupt_rx();放到中斷程序中，如下：

void interrupt isr(void)

{

if(SSP1IE SSP1IF)

{

i2c_salve_interrupt_tx();

i2c_salve_interrupt_rx();

SSP1IF=0;

}

}

將初始化函數init_i2c_slave();放到主函數中

void main()

{

init_i2c_slave();

}

頭文件 :i2c_salve.h

#ifndef _I2C_SALVE_H

#define _I2C_SALVE_H

void init_i2c_slave();

void i2c_salve_interrupt_tx();

void i2c_salve_interrupt_rx();

#endif

代碼：i2c_salve.c

#include ;

#define input 1

#define RX_BUF_LEN 29

#define while_delay 6000

unsigned char i2c_address,word_address,Register[29];

unsigned char RANDOM_READ,i2c_counter;

extern unsigned char A_readflag;

/*I2C SALVE */

void init_i2c_slave()

{

TRISB6 = input;

TRISB4 = input;

SSP1CONbits.SSPM0 = 0;

SSP1CONbits.SSPM1 = 1;

SSP1CONbits.SSPM2 = 1;

SSP1CONbits.SSPM3 = 0;// I2C slave mode ,7bit address

SSP1CONbits.CKP = 1; // enable clock

SSP1ADD =0xA0; //slave address is 0xa0

SSP1CONbits.SSPEN=1;//enable I2c

SSPSTAT=0;

PIE1bits.SSP1IE = 1;//Enabe interrupt MSSP

INTCONbits.PEIE = 1;

INTCONbits.GIE = 1;

}

/*I2C salve mode interrupt */

void i2c_salve_interrupt_tx()//master read

{

unsigned char Temp;

unsigned int timercounter;

Temp=SSP1STAT;

Temp = 0x2D;

if(SSP1STATbits.R_nW ==1)//Read operation.

{

A_readflag=0;

SSP1IF = 0;

i2c_address = SSP1BUF;

i2c_counter = word_address;

while(i2c_counter RX_BUF_LEN)

{

SSP1BUF=Register[i2c_counter];//send data

SSP1CONbits.CKP=1;// enable colck

timercounter=while_delay;