利用單片機的硬件I2C讀取24C02具有更高的執(zhí)行效率宇色。代碼更為精簡。

1 I2C寫數(shù)據(jù)

void I2CWrite(u8 sub, u8* ptr, u16 len)
{
    do {
        I2C_SendPacket(sub, ptr, len);                                      //write data
        while(i2c.busy);                                                    //till I2C is not work
    } while(!i2c.ack);
}
u8 I2C_SendPacket(u8 sub, u8* ptr, u16 cnt)
{
    u8 i;
    i2c.opt = WR;                                                               //i2c option flag set to write
    i2c.cnt = cnt;                                                              //number to send
    i2c.sub = sub;                                                              //sub address
    i2c.busy = true;                                                            //I2C operation starts
    i2c.ack = false;

    if ((sub % PAGESIZE) > 0) {
        u8 temp = MIN((PAGESIZE - sub % PAGESIZE), i2c.cnt);                    //Need temp number of data, just right to the page address
        if(I2C_SendBytes(sub, ptr, temp)) {                                     //If WRITE successful
            ptr +=  temp;                                                       //Point to the next page
            i2c.cnt -=  temp;
            sub += temp;
        }
        if (i2c.cnt == 0) return true;                                          //i2c.cnt = 0 means transmition complete
    }
    for (i = 0; i < (i2c.cnt / PAGESIZE); i++) {
        if (I2C_SendBytes(sub, ptr, PAGESIZE)) {                                //Full page write
            ptr += PAGESIZE;                                                    //Point to the next page
            sub += PAGESIZE;
            i2c.cnt -= PAGESIZE;
        }
        if (i2c.cnt == 0) return true;
    }
    if (i2c.cnt > 0) {
        if (I2C_SendBytes(sub, ptr, i2c.cnt)) return true;
    }
    i2c.busy = false;                                                           //I2C operation ends
    i2c.ack = true;
    return false;
}

2 I2C讀數(shù)據(jù)

void I2CRead(u8 sub, u8* ptr, u16 len)
{
    do {
        I2C_RcvPacket(sub, ptr, len);                                           //read data
        while(i2c.busy);                                                        //till I2C is not work
    } while(!i2c.ack);
}
void I2C_RcvPacket(u8 sub, u8* ptr, u16 cnt)
{
    i2c.busy = true;                                                            //I2C operation starts
    i2c.ack = false;
    i2c.sub = sub;
    i2c.ptr = ptr;
    i2c.cnt = cnt;

    I2C_TXByte(i2c.sub);                                                        //Send sub address
    I2C_RevBytes();                                                             //receive bytes
    I2C_GenerateSTOP(I2C1, ENABLE);                                              //Stop transmission
    while((I2C_GetITStatus(I2C1, I2C_IT_STOP_DET)) == 0);                        //Checks whether stop condition has occurred or not.

    i2c.busy = false;                                                           //I2C operation ends
    i2c.ack = true;
    I2C_WaitEEready();
}

3 main函數(shù)

int main(void)
{
    u8 temp,i;
    
    InitSystick();
    LED_Init();
    /*
        Use I2C1 Port to connect external I2C interface type EEPROM 24C02;
        run Write and Read series bytes Data;
    */
    I2C_Initialize();                                                                    //Initial I2C

    I2CWrite(0x10, buffer0, 0x08);                                                //Write 8 bytes from buffer0[128] to 0x10 of EEPROM
    I2CRead(0x10, buffer1, 0x08);                                                 //Read 8 bytes from 0x10 of EEPROM to buffer1[128]

    temp = 0;
    for(i = 0; i < 0x08; i++) {
        if((buffer0[i]) == (buffer1[i])) {
            temp++;
        }
    }
    while(1) {
        LED1_TOGGLE();
        if(temp < 0x08) {
            delay_ms(100);
        }

        else {
            delay_ms(500);
        }
    }
}

如果寫入的數(shù)據(jù)與讀取出來一致，則LED慢閃屯蹦，否則LED快閃。