新唐的n76e003的iic代码的理解

只看该作者 · 2017-7-24 18:09

我想请问这个从机发送接收代码是怎么实现的
/*---------------------------------------------------------------------------------------------------------*/
/*                                                                                                       */
/* Copyright(c) 2015 Nuvoton Technology Corp. All rights reserved.                                        */
/*                                                                                                       */
/*---------------------------------------------------------------------------------------------------------*/

//***********************************************************************************************************
//  File Function: N76E003 I2C Slave demo code
//***********************************************************************************************************

#include "N76E003.h"
#include "Common.h"
#include "Delay.h"
#include "SFR_Macro.h"
#include "Function_define.h"

//***********************************************************************************************************
//  N76E885-series I2C slave mode demo code, the Slave address = 0xA4
//
// ____________          _____________
//  |          | SDA |          |
//  |          |<-------->|          |
//  |          |       |          |
//  |N76E003(M) |       | N76E003(S) |
//  |(I2C_Master)|       | (I2C_Slave) |
//  |          | SCL |          |
//  |          |--------->|          |
//  |____________|       |_____________|
//
//  The protocol of I2C is same the "24LC64"
//***********************************************************************************************************

#define I2C_CLOCK             13
#define EEPROM_SLA             0xA4

UINT8 data_received[34], data_num = 0;

//========================================================================================================
void I2C_ISR(void) interrupt 6
{
switch (I2STAT)
{
      case 0x00:
         STO = 1;
         break;

      case 0x60:
         AA = 1;
         //P3 = 0x60;
         break;

      case 0x68:
P02 = 0;
         while(1);
         break;

      case 0x80:
         //P3 = 0x80;
         data_received[data_num] = I2DAT;
         data_num++;

         if (data_num == 34)
            AA = 0;
         else
            AA = 1;
         break;

      case 0x88:
         //P3 = 0x88;
         data_received[data_num] = I2DAT;
         data_num = 0;
         AA = 1;
         break;

      case 0xA0:
         //P3 = 0xA0;
         AA = 1;
         break;

      case 0xA8:
         //P3 = 0xA0;
         I2DAT = data_received[data_num];
         data_num++;
         AA = 1;
         break;

      case 0xB8:
         //P3 = 0xB8;
         I2DAT = data_received[data_num];
         data_num++;
         AA = 1;
         break;

      case 0xC0:
         AA = 1;
         break;

      case 0xC8:
         //P3 = 0xC8;
         AA = 1;
         break;
}

SI = 0;
while(STO);
}

//========================================================================================================
void Init_I2C(void)
{
P13_Quasi_Mode;                      //set SCL (P13) is Quasi mode
P14_Quasi_Mode;                      //set SDA (P14) is Quasi mode

SDA = 1;                               //set SDA and SCL pins high
SCL = 1;

set_P0SR_6;                            //set SCL (P06) is  Schmitt triggered input select.

set_EI2C;                            //enable I2C interrupt by setting IE1 bit 0
set_EA;

I2ADDR = EEPROM_SLA;                   //define own slave address
set_I2CEN;                            //enable I2C circuit
set_AA;
}

//========================================================================================================
void main(void)
{

Set_All_GPIO_Quasi_Mode;

/* Initial I2C function */
Init_I2C();                               //initial I2C circuit

while (1);
/* =================== */
}