_iicg.c

用于开发Linux的Bootloader源代码

/*
//==Program Name:iic.c================================
//--Program Description：iic fuction-------- 
//--Author:Yanyou Song---E-mail:[e-mail]-----------------
//--Some Program&Fuction May Have BUG------------------------
//--The Code Is Strictly In public,Forbiding Updata On Net---
//--Use This Code Caused All The Problem Is Irrespective The 
Programmer,Aftermath By Yourself!!---------------------------
//--Copyright Yanyou Song,All rights reserved.---------------
//--Design Data:2006-09-11 ----------------------------------
//===========================================================

//===========程序名称：Main_entry.c======================= 
//--程序目的：iic函数-----------------------------
//-----设计&编写者 :宋彦佑--电子邮件:[e-mail]---------
//------------程序&函数有存在BUG的可能--------------------
//------此原码不公开！！不允许公布在因特网上!!------------
//--使用此代码引起的一切问题与设计&编写者无关，后果自负---
//------------作者保留此代码的所有权力--------------------
//----设计日期：-2006-now---------------------------------
//========================================================

//--------最后更改日期---------
//---the last revision time----
//2006-10-20 

*/

#include "snds.h"
#include "std.h"


/*=====================================================================*/
/*                       IIC EEPROM ADDRESS MAP                        */
/*      Case of Using 64Kbit(=8K bytes) IIC Serial EEPROM,             */
/*      The address range is 0x0 to 0x1fff                             */
/*=====================================================================*/
#define IIC_DEV_0	0xa0    //IIC device's slave address
#define S_WRITE		0x00    //Write IIC data for slave
#define S_READ		0x01    //Read IIC data for slave

/*=====================================================================*/
/*                       CONTROL REGISTERS                             */
/*=====================================================================*/
#define BF 		0x01        //Buffer flag
#define IEN		0x02        //Interrupt enable
#define LRB		0x04        //Last bit received
                                    //ACK not received
#define ACK		0x08        //Acknowlege enable
                                    //Generate an ACK signal at 9th SCL
#define NOACK		0x00        //No more received data is required
                                    //from the slave
#define START		0x10
#define STOP		0x20
#define RESTART		0x30
#define BUSY		0x40
#define IICRESET	0x80        //Reset the IIC-BUS controller


//*********************************************************
//*                   IIC SETUP ROUTINE                   *
//*********************************************************
void iicSetup(void)
    {
	 IICCON = IICRESET;
	 IICPS = 0x00000025;  
    }
int iicread(uint16 ReadAddr)
	{
	 char i;
	 unsigned char rdata; 
	 unsigned int con_wait;
	 int error=0;
	 iicSetup();
	 con_wait=0;
	 while(IICCON&BUSY)  
	 IICCON = START|ACK;   
	 IICBUF=IIC_DEV_0|S_WRITE;
	 con_wait=0;
	 while(!(IICCON &BF))
	 IICBUF = ReadAddr>>8;
	 con_wait=0;
	 while(!(IICCON &BF))	 
	 IICBUF = ReadAddr&0xff;
	 con_wait=0;
	 while(!(IICCON &BF))	 
	 IICCON = RESTART; 
	 IICCON = START|ACK;
	 IICBUF = IIC_DEV_0|S_READ;
	 con_wait=0;
	 while(!(IICCON &BF))  
	 IICCON=ACK;
	 con_wait=0;
	 while(!(IICCON &BF))  
		 rdata=IICBUF;
		 con_wait=0;
		 while(!(IICCON &BF))
	 IICCON = NOACK;
	 con_wait=0;
	 while(!(IICCON &BF))
	 IICCON = STOP;
     return 0;
	}

int iicwrite(unsigned int WriteAddr,unsigned char pdata)
{
     char i;
	 unsigned int con_wait;
	 int error=0;	 
	 iicSetup();
	 while(IICCON&BUSY)  
	 IICCON=START|ACK;
	 IICBUF=0xa0;
	 while(!(IICCON &BF))
	 IICBUF=WriteAddr>>8;	 
	 while(!(IICCON &BF))
	 IICBUF=WriteAddr&0x00ff;	
	 while(!(IICCON &BF))
		 IICBUF=pdata;
	 while(!(IICCON &BF))
	 IICCON=STOP;
	 Delay(6000);
	 return error;
}