This example describes how to make a communication with I2C EEPROM

Procedure for EEPROM interface with Cortex M4

1. Initialize UART0
2. Power: In the PCONP register, set the PCI2C0 bit
3. Configure pins P0.27 (CH0) and P0.28 for I2C function using IOCON registers
4. Clear all the I2C registers and Flags
5. Enable I2C
6. Configure the I2C frequency as 100KHz or 400KHz
7. Enable I2C Interrupt
   Write a block data:
8. Send START
9. Send device address with write
10. Send the block address where we going to write a block of data
11. Send a block of data
12. Send STOP signal
    Read a block of data:
13. Send START
14. Send device address with write
15. Send the block address where we are going to read a block of data
16. Send a REPEATED START
17. Send device address with read
18. Read a byte of data and send ACK signal
19. Send a NACK signal if the byte read is the last byte
20. Send STOP
21. Display the data received in HyperTerminal

#include <LPC407x_8x_177x_8x.h>
#include "uart0.h"

#define DEVICE_ADDR 0xA0

unsigned char Status=0,rbuf[20],tbuf[20]="ARM CORTEX M4\r",Str[6];
unsigned char Status_Flag=0,i=0;

void Init_I2C0(void);
void Page_Write(unsigned char *str);
void Page_Read(unsigned char *str);
void wait_i2c(void);
void delay_ms(long ms);
void Start(void);
void Wait_I2C(void);

void I2C0_IRQHandler(void)
{ 
		Status_Flag = 1;
		Status = LPC_I2C0->STAT;									//	Read Status byte
		LPC_I2C0->CONCLR =	0x28;									//  Clear Interrupt Flag
}	

int main(void)
{	
		//1.Initialize UART
		init_serial();	
		Init_I2C0();
		delay_ms(100);
	
		Page_Write(tbuf);
		delay_ms(100);
	
		while(1)
		{
			Page_Read(rbuf);
			//21. Display the read data in HyperTerminal
			UART0_puts(rbuf);
			delay_ms(1000);
		}
}

void Init_I2C0(void)
{
	//2. set bit PCI2C0 
		LPC_SC->PCONP |= (1 << 7); 										/* enable power to UART0*/

	//3. Configure pins P0.27 and P0.28 for I2C Clock and data
		LPC_IOCON->P0_27 |=  1;        								/* Pin P0.2 used as I2C DATA */
		LPC_IOCON->P0_28 |=  1;        								/* Pin P0.3 used as I2C CLK */
	
	//4. Clear all the Registers
		LPC_I2C0->CONCLR=	0x6C;
	
	//5. Enable I2C
		LPC_I2C0->CONSET=	0x40;
	
	//6. Set I2C Frequency as 400KHz
	//   30MHz/400KHz = 75=SCLH+SCLL=38+37=75
		LPC_I2C0->SCLH  = 38;
		LPC_I2C0->SCLL  = 37;	
	
	//7. Enable Interrupt
		NVIC->ISER[0] |= (1<<10);					//Enable I2C0
		NVIC->IP[2]   |= (0x3<<19); 			//Interrupt Priority 0-High, 31-low		
}

void Start(void)
{
	 LPC_I2C0->CONCLR = 0x2C;
	 LPC_I2C0->CONSET = 0x20; 									
	 Wait_I2C();	
}

void Page_Write(unsigned char *str)
{
 
	 Start();																				//8. Send Start 	
	
	 LPC_I2C0->DAT = 0xA0;													//9. Send device Address + write
	 Wait_I2C();

	 LPC_I2C0->DAT=0;																//10. Send block address High
	 Wait_I2C();
	 
	 LPC_I2C0->DAT=0;																//10. Send block address Low
	 Wait_I2C();

	 for(i=0;i<16;i++)
	 {
			LPC_I2C0->DAT = str[i];											//11. Send a block of data
		  Wait_I2C();
	 }
	 LPC_I2C0->CONSET = 0x10; 											//12. Send STOP
}

void Page_Read(unsigned char *str)
{
	 Start();																				//13. Send Start 	

	 LPC_I2C0->DAT    = 0xA0;												//14. Send device Address + write 
	 Wait_I2C();
	
	 LPC_I2C0->DAT=0;																//15. Send block address High
	 Wait_I2C();
	 
	 LPC_I2C0->DAT=0;																
	 Wait_I2C();																		//15. Send block address Low
	
	 Start();	 																			//16. Send r-Start
	
 	 LPC_I2C0->DAT = 0xA1;													//17. Send device Address + read
	 Wait_I2C();
	
	 for(i=0;i<15;i++)													  	//18.	Read a byte of data and send ACK signal
	 {
			LPC_I2C0->CONSET = 0x04; 
			Wait_I2C();
			str[i] = LPC_I2C0->DAT;
	 }
	 
	 //Last byte																		//19.	Send a NACK signal and Read the Last byte
	 LPC_I2C0->CONCLR = 0x4; 
	 Wait_I2C();
	 str[i] = LPC_I2C0->DAT;
	 LPC_I2C0->CONSET=0x10; 												//20. Send STOP
}

void Wait_I2C(void)
{
		while(Status_Flag == 0); 
		Status_Flag = 0;
}

void delay_ms(long ms) 					// delay 1 ms per count @ CCLK 120 MHz
{
		long i,j;
		for (i = 0; i < ms; i++ )
		for (j = 0; j < 26659; j++ );
}