GPIO模擬I2C存取EEPROM

/**************************************************************************//**

 * [url=home.php?mod=space&uid=288409]@file[/url]     main.c

 * [url=home.php?mod=space&uid=895143]@version[/url]  V1.00

 * $Revision: 3 $

 * $Date: 15/08/18 11:54a $

 * [url=home.php?mod=space&uid=247401]@brief[/url]    NUC200 Series LED Controller Sample Code

 *

 * @note

 * Copyright (C) 2011 Nuvoton Technology Corp. All rights reserved.

 *

 ******************************************************************************/

#include <stdio.h>

#include "NUC230_240.h"

#include "NuEdu-Basic01.h"

#define I2C_ADDRESS_w 0xa0

#define I2C_ADDRESS_r 0xa1

#define I2C_DELAY_TIME  10 /* us */

#define ACK   0

#define NO_ACK   1

#define I2C_CLK PA11

#define I2C_DAT PA10

void I2C_init(void) {

GPIO_SetMode(PA, BIT10, GPIO_PMD_OPEN_DRAIN);//I2C_CLK

GPIO_SetMode(PA, BIT11, GPIO_PMD_OPEN_DRAIN);//I2C_DAT 

I2C_CLK=1;

I2C_DAT=1;

}



void I2C_start(void) {



 /* I2C start sequence is defined as 

  * a High to Low Transition on the data

  * line as the CLK pin is high */

 I2C_DAT=1;

 I2C_CLK=1;

 CLK_SysTickDelay(I2C_DELAY_TIME); 

 I2C_DAT=0;

 I2C_CLK=0;

 CLK_SysTickDelay(I2C_DELAY_TIME); 

}



void I2C_stop(void) {

  

 /* I2C stop sequence is defined as 

  * data pin is low, then CLK pin is high,

  * finally data pin is high. */

  I2C_DAT=0;

        I2C_CLK=1;

        I2C_DAT=1; 

}



unsigned char I2C_write(unsigned char data) {

  

 /* An I2C output byte is bits 7-0

   * (MSB to LSB).  Shift one bit at a time

  * to the MDO output, and then clock the

  * data to the I2C Slave */



 unsigned char i,temp;



 /* Write to slave */

 for(i = 0; i < 8; i++) 

        {  

        /* Send data bit */

        if((data&0x80)==0x80)         

                I2C_DAT=1;

          else

                        I2C_DAT=0;

  data <<= 1;   /* Shift one bit */

  I2C_CLK=1; /* SCL: High */

  CLK_SysTickDelay(I2C_DELAY_TIME); 

  I2C_CLK=0; /* SCL: Low */

  CLK_SysTickDelay(I2C_DELAY_TIME); 

 }

 I2C_DAT=1;

 

 I2C_CLK=1;  /* SCL: High */

 CLK_SysTickDelay(I2C_DELAY_TIME/2); 

 temp=I2C_DAT; /* Read ACK bit from slave */

 CLK_SysTickDelay(I2C_DELAY_TIME/2); 

 I2C_CLK=0;  /* SCL: Low */

 CLK_SysTickDelay(I2C_DELAY_TIME); 

 return temp;

}



unsigned char I2C_read(unsigned char send_ack) 

{

  

 unsigned char i, data;



 data = 0x00;



 /* Read from slave */

 for(i = 0; i < 8; i++) {

  data <<= 1;   /* Shift one bit */

  data |= I2C_DAT; /* Read data bit */

  I2C_CLK=1; /* SCL: High */

  CLK_SysTickDelay(I2C_DELAY_TIME); 

  I2C_CLK=0; /* SCL: Low */

  CLK_SysTickDelay(I2C_DELAY_TIME); 

 }



 /* Send ACK bit to slave */

 I2C_DAT=send_ack;

 I2C_CLK=1;   /* SCL: High */

CLK_SysTickDelay(I2C_DELAY_TIME); 

 I2C_CLK=0;   /* SCL: Low */

CLK_SysTickDelay(I2C_DELAY_TIME); 



 return data;

 

}



/*---------------------------------------------------------------------------------------------------------*/

/*  MAIN function                                                                                          */

/*---------------------------------------------------------------------------------------------------------*/

int main(void)

{



    SYS_Init();

    UART0_Init();

        I2C_init();

        I2C_start();

        printf("ack=0x%x,\n\r",I2C_write(I2C_ADDRESS_w));

        printf("ack=0x%x,\n\r",I2C_write(0x00)); //eeprom address high

        printf("ack=0x%x,\n\r",I2C_write(0x00));//eeprom address low

        printf("ack=0x%x,\n\r",I2C_write(0x55));//write 0x55

        I2C_stop();

        CLK_SysTickDelay(10000); //delay 10ms

        I2C_start();

        printf("ack=0x%x,\n\r",I2C_write(I2C_ADDRESS_w));

        printf("ack=0x%x,\n\r",I2C_write(0x00)); //eeprom address high

        printf("ack=0x%x,\n\r",I2C_write(0x00));//eeprom address low

        I2C_start();

        printf("ack=0x%x,\n\r",I2C_write(I2C_ADDRESS_r));

        printf("data=0x%x,\n\r",I2C_read(NO_ACK));

        I2C_stop();

        while(1);

                

}