iic.c

武汉创维特ARM7实验箱的全部源代码

/****************************************************************************/
/*                                                                          */
/* FILE NAME                                      VERSION                   */
/*                                                                          */
/* IIC.C                                            1.0                     */
/*                                                                          */
/* DESCRIPTION                                                              */
/*                                                                          */
/*     JX44B0(S3C44B0X)IIC驱动实验                                          */
/*                                                                          */
/*                                                                          */
/* DATA STRUCTURES                                                          */
/*                                                                          */
/* FUNCTIONS :                                                              */
/*     在JX44B0教学实验箱进行IIC实验                                        */
/*                                                                          */
/* DEPENDENCIES                                                             */
/*     JX44B0-1                                                             */
/*     JX44B0-2                                                             */
/*     JX44B0-3                                                             */
/*                                                                          */
/*                                                                          */
/* NAME:                                                                    */
/* REMARKS:                                                                 */
/*                                                                          */
/*								Copyright (C) 2003 Wuhan CVTECH CO.,LTD     */
/****************************************************************************/

/****************************************************************************/
/* 学习JX44B0中IIC总线编程方法：                                            */
/****************************************************************************/

/* 包含文件 */
#include "44b.h"
#include "44blib.h"
#include "rtc.h"

#define U8			unsigned char
#define U32			unsigned long

#define WRDATA	    (1)
#define POLLACK     (2)
#define RDDATA	    (3)
#define SETRDADDR   (4)
#define IICBUFSIZE 	0x20

typedef (*ISR_ROUTINE_ENTRY)(void);


/* functions */
void Test_Iic(void);
void IicInt(void);
void IicInt(void);

void iic_write_24C08(U32 slvAddr,U32 addr,U8 data);
void iic_read_24C08(U32 slvAddr,U32 addr,U8 *data);
void write_24C08(unsigned char slvAddr,unsigned char addr,unsigned char data);

void iic_isr(void);
void IsrIRQ() __attribute__ ((interrupt("IRQ")));


int iic_data_tx_size;
int iic_data_rx_size;

int iic_data_tx_index;
int iic_data_rx_index;

unsigned char iic_buffer[256];
unsigned char iic_command;
unsigned int  iic_status;

/*****************************************************************************
// Function name	: IsrIRQ
// Description	    : 非矢量方式下中断的查表处理
//					  中断地址表位于0x0c7fff00开始的256字节
// Return type		: void
// Argument         : void
*****************************************************************************/
void IsrIRQ()
{
	int count = 0;
	unsigned int isr_pending;
	unsigned int isr_mask = 0x00000001;
	
	unsigned int isr_mask_set = rINTMSK;
	
	ISR_ROUTINE_ENTRY isr_routine_entry = (ISR_ROUTINE_ENTRY)0x0;
	
	isr_pending = (rINTPND & ~isr_mask_set);
	
	while(isr_mask)
	{
		if((isr_pending&isr_mask) == 0)
		{
			count+=4;
			isr_mask <<= 1;
			continue;
		}

		isr_routine_entry = (ISR_ROUTINE_ENTRY)(*(int*)(HandleADC+count));
		break;
	}
	
	if(isr_routine_entry) (*isr_routine_entry)();
}

/*****************************************************************************
// Function name	: init_interrupt_handler
// Description	    : 非矢量方式下中断向量表初始化处理
// Return type		: void
// Argument         : irq_handler
//					  中断处理函数入口
*****************************************************************************/
void init_interrupt_handler(unsigned int irq_handler) 
{
	int i;
	
	rINTPND = 0x00000000;							/* 清除所有未决的中断	*/
	rI_ISPC = 0x03FFFFFF; 
	
	for( i = 0; i < 256; i+=4)						/* 清除中断表			*/
		*(unsigned int*)(_ISR_STARTADDRESS+i) = 0;

	*(unsigned int*)(HandleIRQ) = irq_handler;		/* 设置IRQ模式处理函数	*/
}

/*****************************************************************************
// Function name	: install_isr_handler
// Description	    : 非矢量方式下中断向量的安装
// Return type		: void
// Argument         : irq_no, 中断号
//					  irq_routine, 中断处理函数地址
*****************************************************************************/
void install_isr_handler(int irq_no, void* irq_routine)
{
	*(unsigned int*)(irq_no) = (unsigned int)irq_routine;
}

/*****************************************************************************
// Function name	: Main
// Description	    : IIC测试程序主函数
//                    IIC总线实现对JX44B0教学系统上的EEPROM芯片24C08进行读写操作
// Return type		: int
// Argument         : void
*****************************************************************************/
int Main(void)
{
	int old_index ;
	
    rINTCON = 0x7;						/* Non-vectored,IRQ/FIQ disable		*/
	
	init_interrupt_handler((unsigned int)IsrIRQ);
	install_isr_handler(HandleIIC, 	(void*)IicInt);

    rINTMOD=0x0;						/*设置所有中断为IRQ模式				*/
	
    rINTMSK=(0x07ffffff&~(BIT_GLOBAL|BIT_IIC));		/* 使能TICK中断			*/

    rINTCON=0x5;						/* IRQ enable,FIQ disable			*/
    
    Test_Iic();
    
    while(1);
}

/*****************************************************************************
// Function name	: iic_init
// Description	    : IIC初始化
// Return type		: void
// Argument         : void
*****************************************************************************/
void iic_init(void)
{
    rPCONF = (rPCONF&0xFFFFFF0) | 0xa;	/*PF0:IICSCL, PF1:IICSDA			*/
    rPUPF |=0x3;						/*pull-up disable					*/
    
    Delay(100);

    rIICCON=(1<<7)|(0<<6)|(1<<5)|(0xf);	/*Enable interrupt, IICCLK=MCLK/16  */

    rIICADD=0x10;						/* S3C44B0X address					*/
    rIICSTAT=0x10;
}

/*****************************************************************************
// Function name	: Test_Iic
// Description	    : test iic
// Return type		: void
// Argument         : void
*****************************************************************************/
void Test_Iic(void)
{
    unsigned int i,j;
    static unsigned char data[128];

   	Uart_Printf("[IIC Test using KS24C08]\n");

	iic_init();
	    
    Uart_Printf("Write test data into KS24C08\n");
    
    for(i=0;i<128;i++)
    {
    	Uart_Printf("\rWrite 0x%02x", i);
		iic_write_24C08(0xa0,(U8)i,i+0x18);	  /*IIC写操作，写128个字节 0-255*/
	}
	Uart_Printf("\n");
		
    for(i=0;i<128;i++)	data[i]=0;
      
    Uart_Printf("Read test data from KS24C08\n");
    for(i=0;i<128;i++)
    {
    	Uart_Printf("\rRead 0x%02x", i);
		iic_read_24C08(0xa0,(U8)i,&(data[i]));		/*IIC读操作,读取一个字节*/
	}
	Uart_Printf("\n");

    for(i=0;i<16;i++)
    {
		for(j=0;j<16;j++) Uart_Printf("%2x ",data[i*16+j]);
		Uart_Printf("\n");
    }
}

/*****************************************************************************
// Function name	: iic_write_24C08
// Description	    : write data to 24c08
// Return type		: void
// Argument         : U32 slvAddr : Slave addressdata
// Argument         : U32 addr    : address into chip
// Argument         : U8 data     : data by writen
*****************************************************************************/
void iic_write_24C08(U32 slvAddr,U32 addr,U8 data)
{
    int index;
    
    iic_command=WRDATA;
    iic_data_tx_index=0;
    iic_buffer[0]=(U8)addr;
    iic_buffer[1]=data;
    iic_data_tx_size=2;
    
    rIICDS  = slvAddr;
    rIICSTAT= 0xf0; 					/*MasTx,Start						*/
    
    /* Clearing the pending bit isn't needed because the pending bit has	*/
	/* been cleared.														*/
    while(iic_data_tx_size!=-1);
    
	rIICSTAT=0xd0;						/*top MasTx condition				*/
	rIICCON=0xaf;						/*resumes IIC operation.			*/
	Delay(1);							/*until stop condtion is in effect.	*/
    
    iic_command=POLLACK;

    while(1)
    {
		rIICDS=slvAddr;
		iic_status=0x100;
		rIICSTAT=0xf0;					/*MasTx,Start						*/
		rIICCON=0xaf;					/*resumes IIC operation.			*/

		while(iic_status==0x100);

		if(!(iic_status&0x1))
	 	   break;						/*when ACK is received				*/
    }
    rIICSTAT=0xd0;						/*stop MasTx condition				*/
    rIICCON=0xaf;						/*resumes IIC operation.			*/
    Delay(1);							/*until stop condition is in effect.*/
    
    /*write is completed.*/
}

/****************************************************************************
// Function name	: iic_read_24C08
// Description	    : read data from 24c08
// Return type		: void
// Argument         : U32 slvAddr : Slave address
// Argument         : U32 addr    : address into chip
// Argument         : U8 *data    : data buffer
*****************************************************************************/
void iic_read_24C08(U32 slvAddr,U32 addr,U8 *data)
{
    iic_command=SETRDADDR;
    iic_data_tx_index=0;
    iic_buffer[0]=(U8)addr;
    iic_data_tx_size=1;

    rIICDS=slvAddr;
    rIICSTAT=0xf0;						/* MasTx,Start						*/
    
    /* Clearing the pending bit isn't needed because the pending bit has	*/
    /* been cleared.														*/
    while(iic_data_tx_size!=-1);

    iic_command=RDDATA;

    iic_data_rx_index=0;
    iic_data_rx_size=1;
    
    rIICDS=slvAddr;
    rIICSTAT=0xb0; 						/*MasRx,Start						*/
    rIICCON=0xaf;  						/*resumes IIC operation.			*/
    while(iic_data_rx_size!=-1);
    
	rIICSTAT=0x90;  					/*stop MasRx condition				*/
	rIICCON=0xaf;   					/*resumes IIC operation.			*/
	Delay(1);							/*until stop condition is in effect.*/
										/*too long time...					*/

    *data=iic_buffer[1];
}
/****************************************************************************
// Function name	: IicInt
// Description	    : iic中断处理函数
// Return type		: void
// Argument         : void
*****************************************************************************/
void IicInt(void)
{
	unsigned char data;
    U32 iicSt,i;
    rI_ISPC=BIT_IIC;

    iicSt=rIICSTAT; 
    
    switch(iic_command)
    {
	case POLLACK:
	    iic_status=iicSt;
	    break;

	case RDDATA:
	
		iic_data_rx_size--;
		
		iic_buffer[iic_data_rx_index++]=rIICDS;

		if( iic_data_rx_size == -1 ) break;    

		/* The last data has to be read with no ack. */
	    if((iic_data_rx_size)==0)
		{
			rIICCON=0x2f;				/* resumes IIC operation with NOACK.*/
		}
	    else  
		{
			rIICCON=0xaf;				/* resumes IIC operation with ACK	*/
		}
	    break;

	case WRDATA:
	case SETRDADDR:
	
		iic_data_tx_size--;
		if(iic_data_tx_size==-1) break;

		
	    rIICDS = iic_buffer[iic_data_tx_index++];  /*iic_buffer[0] has dummy*/
	    
	    for(i=0;i<10;i++);				/*until rising edge of IICSCL		*/
	    
	    rIICCON=0xaf;	    			/* resumes IIC operation.			*/		
	    
	    break;
	    
	default:
	    break;	  
    }
}