main.c

开发环境：ADS。测试IIC接口

// Include Standard LIB  files
#include "AT91SAM7X-EK.h"
#include "include/AT91SAM7X256.h"
#include "include/lib_AT91SAM7X256.h"
#define AT91_BAUD_RATE				115200
#define	WAIT_TIME					AT91B_MCK
#define AT91C_TWI_CLOCK				330000
#define AT91C_EEPROM_I2C_ADDRESS	(0x50<<16)
#define MCK							48000000
#define ERROR						(AT91C_TWI_NACK)
#define	EEPROM_TEST_ADDRESS			0x00
#define USART0_INTERRUPT_LEVEL		6
#define USART1_INTERRUPT_LEVEL		7

static const char szembed_header[]=
{
"\n\r================================================"
"\n\r==         Test IIC EEPROM Program            =="
"\n\r================================================\n\r"
};
volatile int	loop;
char			value_write[2]={0};
char			value_read[2]={'Y','Y'};
unsigned char	value_write_flag=0x00;

//*--------------------------------------------------------------------------------------
//* Function Name       : wait
//* Object              : Software waiting loop
//* Input Parameters    : none. Waiting time is defined by the global variable LedSpeed.
//* Output Parameters   : none
//*--------------------------------------------------------------------------------------
void wait ( void )
{
	//Wait at least 10 ms before value is written into EEPROM
    for (loop=0; loop<10000; loop++){};
}

//*----------------------------------------------------------------------------
//* Function Name       : delay
//* Object              : Wait
//* Input Parameters    : none
//* Output Parameters   : none
//* Functions calAT91B_LED    : none
//*----------------------------------------------------------------------------
void delay ( void )
{
//* Set in Volatile for Optimisation
    volatile unsigned int    i ;
//* loop delay
    for ( i = 0 ;(i < WAIT_TIME/50 );i++ ) ;
}

//*----------------------------------------------------------------------------
//* Function Name       : Usart_c_irq_handler
//* Object              : C handler interrupt function 
//* Input Parameters    : none
//* Output Parameters   : none
//*----------------------------------------------------------------------------
void Usart_c_irq_handler(void)
{
	char status;
	AT91PS_USART COM0 = AT91C_BASE_US0;
	//* get Usart status register
	status = COM0->US_CSR;
	if ( status & AT91C_US_RXRDY)
	{
	//* Get byte to write to eeprom
	    value_write[0]=AT91F_US_GetChar(COM0);
	    AT91F_US_PutChar(COM0,value_write[0]);
	    value_write_flag=0x01;
	}
	//* Check error
	if ( status & AT91C_US_FRAME)
	{
		AT91F_US_PutChar (COM0, 'F');
	}
	//* Reset the satus bit
	COM0 ->US_CR = AT91C_US_RSTSTA;
}

//*----------------------------------------------------------------------------
//* Function Name       : Usart_init
//* Object              : USART initialization
//* Input Parameters    : none
//* Output Parameters   : TRUE
//*----------------------------------------------------------------------------
void Usart_init ( void )
{
	AT91PS_USART COM0 = AT91C_BASE_US0;
   	// First, enable the clock of the USART
	AT91F_PMC_EnablePeriphClock ( AT91C_BASE_PMC, 1 << AT91C_ID_US0 ) ;
	//* Configure PIO controllers to periph mode
	AT91F_PIO_CfgPeriph( AT91C_BASE_PIOA,
 		((unsigned int) AT91C_PA0_RXD0    ) |
 		((unsigned int) AT91C_PA1_TXD0    ) |
 		((unsigned int) AT91C_PA3_RTS0    ) |
 		((unsigned int) AT91C_PA4_CTS0    ), // Peripheral A
 		0); // Peripheral B
	// Usart Configure
	AT91F_US_Configure (COM0, AT91B_MCK, AT91C_US_ASYNC_MODE, AT91_BAUD_RATE, 0);
	// Enable usart
	COM0->US_CR = AT91C_US_RXEN | AT91C_US_TXEN;
	//* Enable USART IT error and RXRDY
    AT91F_US_EnableIt(COM0, AT91C_US_FRAME | AT91C_US_RXRDY);
   	//* open Usart 0 interrupt
	AT91F_AIC_ConfigureIt ( AT91C_BASE_AIC, AT91C_ID_US0, USART0_INTERRUPT_LEVEL,AT91C_AIC_SRCTYPE_INT_HIGH_LEVEL, Usart_c_irq_handler);
	AT91F_AIC_EnableIt (AT91C_BASE_AIC, AT91C_ID_US0);
 	AT91F_US_SendFrame(COM0,(char *)szembed_header,sizeof(szembed_header),0,0);
}

//*=========================================================
//*		INIT
//*=========================================================
//*----------------------------------------------------------------------------
//* \fn    AT91F_SetTwiClock
//* \brief Initialization
//*----------------------------------------------------------------------------
void AT91F_SetTwiClock(void)
{
	int sclock;

	/* Here, CKDIV = 1 and CHDIV=CLDIV  ==> CLDIV = CHDIV = 1/4*((Fmclk/FTWI) -6)*/

	sclock = (10*MCK /AT91C_TWI_CLOCK);
	if (sclock % 10 >= 5)
		sclock = (sclock /10) - 5;
	else
		sclock = (sclock /10)- 6;
	sclock = (sclock + (4 - sclock %4)) >> 2;	// div 4

    AT91C_BASE_TWI->TWI_CWGR	= ( 1<<16 ) | (sclock << 8) | sclock  ;
}

//*=========================================================
//*		WRITE
//*=========================================================
//*----------------------------------------------------------------------------
//* \fn    AT91F_TWI_WriteByte
//* \brief Send a byte to a slave device
//*----------------------------------------------------------------------------
int AT91F_TWI_WriteByte(const AT91PS_TWI pTwi ,int mode, int int_address, char *data2send, int nb)
{
	unsigned int status,error=0;
//	unsigned int counter=0;
	// Set TWI Internal Address Register
	if ((mode & AT91C_TWI_IADRSZ) != 0) pTwi->TWI_IADR = int_address;
	// Set the TWI Master Mode Register
	  pTwi->TWI_MMR = mode & ~AT91C_TWI_MREAD;
	// nb = 1 Byte Write mod, nb > 2 Page Write mod
	if(nb <2){
		pTwi->TWI_CR = AT91C_TWI_START | AT91C_TWI_MSEN | AT91C_TWI_STOP;
		pTwi->TWI_THR = *data2send;
	}
/*
	else{
		unsigned int p,d; // p: page number, d: data offset in page
		d = nb%0x10;
		p = (unsigned int)(nb/0x10);
		if(p<=0){
			AT91F_DBGU_Printk("\n\rwrite in the same page");
			// Set the TWI Master Mode Register
			for(counter=0;counter<nb;counter++){
				pTwi->TWI_CR = AT91C_TWI_START | AT91C_TWI_MSEN;
				if (counter == (nb - 1)) pTwi->TWI_CR = AT91C_TWI_STOP;
				status = pTwi->TWI_SR;
				if ((status & ERROR) == ERROR) error++;
				while (!(status & AT91C_TWI_TXRDY)){
					status = pTwi->TWI_SR;
					if ((status & ERROR) == ERROR) error++;
				}
				pTwi->TWI_THR = *(data2send+counter);
	    	}
		}
		else if(p>0){
			unsigned int j;
			AT91F_DBGU_Printk("\n\rwrite more then one page");
			
			pTwi->TWI_CR = AT91C_TWI_START | AT91C_TWI_MSEN;
			for(j=0; j<=p; j++){
			
			// pTwi->TWI_MMR = 0x500100 | (j << 16);//select the page 0 - p
			 pTwi->TWI_IADR = int_address;
			// uprintf("\n\r0x%x\n\r",pTwi->TWI_MMR);
			for(counter=0;counter<16;counter++){
				if ((counter == (16 - 1))&&(d == 0)&&(j > p)) pTwi->TWI_CR = AT91C_TWI_STOP;
				status = pTwi->TWI_SR;
				if ((status & ERROR) == ERROR) error++;
				while (!(status & AT91C_TWI_TXRDY)){
					status = pTwi->TWI_SR;
					if ((status & ERROR) == ERROR) error++;
				}// end while (!(status & AT91C_TWI_TXRDY))
				pTwi->TWI_THR = *(data2send+counter);
			} //for(counter=0;counter<nb;counter++)
            } //for(j=0; j<=p; j++)

            //write the last page data number is d
            pTwi->TWI_IADR = int_address;
            for(counter=0;counter<d;counter++){
            	pTwi->TWI_CR = AT91C_TWI_START | AT91C_TWI_MSEN;
            	if (counter == (d - 1)) pTwi->TWI_CR = AT91C_TWI_STOP;
            	status = pTwi->TWI_SR;
            	if ((status & ERROR) == ERROR) error++;
				while (!(status & AT91C_TWI_TXRDY)){
					status = pTwi->TWI_SR;
					if ((status & ERROR) == ERROR) error++;
				}
            	pTwi->TWI_THR = *(data2send+counter);
	    	}

		} //  else if(p>0)
	}
*/
        // check SR register
	status = pTwi->TWI_SR;
	if ((status & ERROR) == ERROR) error++;
	while (!(status & AT91C_TWI_TXCOMP)){
    		status = pTwi->TWI_SR;
    		if ((status & ERROR) == ERROR) error++;
        }
	return error;
}

//*=========================================================
//*		READ
//*=========================================================
//*----------------------------------------------------------------------------
//* \fn    AT91F_TWI_ReadByte
//* \brief Read a byte from a slave device
//*----------------------------------------------------------------------------
int AT91F_TWI_ReadByte(const AT91PS_TWI pTwi ,int mode, int int_address, char *data, int nb)
{
	unsigned int status,error=0;
//	unsigned int counter=0;
	// Set TWI Internal Address Register
	if ((mode & AT91C_TWI_IADRSZ) != 0) pTwi->TWI_IADR = int_address;
	// Set the TWI Master Mode Register
	pTwi->TWI_MMR = mode | AT91C_TWI_MREAD;
	// Start transfer
	if (nb == 1){
		pTwi->TWI_CR = AT91C_TWI_START | AT91C_TWI_STOP;
		status = pTwi->TWI_SR;
		if ((status & ERROR) == ERROR) error++;
		while (!(status & AT91C_TWI_TXCOMP)){
  			status = pTwi->TWI_SR;
			if ((status & ERROR) == ERROR) error++;
		}
		*(data) = pTwi->TWI_RHR;
	}
/*	
 	else{
		pTwi->TWI_CR = AT91C_TWI_START | AT91C_TWI_MSEN;
		status = pTwi->TWI_SR;
		if ((status & ERROR) == ERROR) error++;

		// Wait transfer is finished
		while (!(status & AT91C_TWI_TXCOMP)){
			status = pTwi->TWI_SR;
			if ((status & ERROR )== ERROR) error++;
			if(status & AT91C_TWI_RXRDY){
				*(data+counter++) = pTwi->TWI_RHR;
				if (counter == (nb - 1)) pTwi->TWI_CR = AT91C_TWI_STOP;
			}
		}
	}
*/
	return error;
}

//*----------------------------------------------------------------------------
//* \fn    AT91F_TWI_Open
//* \brief Initializes TWI device
//*----------------------------------------------------------------------------
void AT91F_TWI_Open(void)
{
	// Configure TWI PIOs
	AT91F_TWI_CfgPIO ();
	// Configure PMC by enabling TWI clock
	AT91F_TWI_CfgPMC ();
	// Configure TWI in master mode
	AT91F_TWI_Configure (AT91C_BASE_TWI);
	// Set TWI Clock Waveform Generator Register
	AT91F_SetTwiClock();
}
//*----------------------------------------------------------------------------
//* Function Name       : main
//* Object              : Main interrupt function
//* Input Parameters    : none
//* Output Parameters   : TRUE
//*----------------------------------------------------------------------------
int main( void )
{
    char status;
   	AT91PS_USART COM0 = AT91C_BASE_US0;
    Usart_init();
    // Enable User Reset and set its minimal assertion to 960 us
    AT91C_BASE_RSTC->RSTC_RMR = AT91C_RSTC_URSTEN | (0x4<<8) | (unsigned int)(0xA5<<24);
    //open port
    AT91F_PMC_EnablePeriphClock ( AT91C_BASE_PMC, 1 << AT91C_ID_PIOA );
    //Initializes TWI device
    AT91F_TWI_Open();
	while(1)
	{
		if(value_write_flag==0x01)
		{
			delay();
			// Write a byte
    		status = AT91F_TWI_WriteByte(AT91C_BASE_TWI, AT91C_EEPROM_I2C_ADDRESS | AT91C_TWI_IADRSZ_1_BYTE, EEPROM_TEST_ADDRESS, value_write, 1);
			// Wait 10 ms before data is written into EEPROM
			wait();
			// Read a byte
			status = AT91F_TWI_ReadByte(AT91C_BASE_TWI, AT91C_EEPROM_I2C_ADDRESS | AT91C_TWI_IADRSZ_1_BYTE ,EEPROM_TEST_ADDRESS, value_read, 1);
			wait();
			AT91F_US_PutChar(COM0,'<');
			wait();
			AT91F_US_PutChar(COM0,value_read[0]);
			wait();
			AT91F_US_PutChar(COM0,'>');
			value_write_flag=0x00;
		}
	}
}